Direct Injection Debacle

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You may have noticed that new cars with gas engines “diesel.”crusty valves

They clatter and rattle a little at idle. It’s especially noticeable if you raise the hood (and remove the big plastic sound-deadening cover almost all new car engines are covered with).

What you’re listening to is the sound of direct injection – which is not-so-quietly replacing port fuel injection (which replaced throttle body, or TBI, injection).

DI is replacing – supplanting – PFI because DI achieves a fractional fuel-efficiency increase compared with PFI. It’s not anything you’d notice. Maybe 1-2 MPG overall. But the gunvernment notices – and that (gunvernment pressure) rather than market demand – is what increasingly drives new vehicle design. A year from now, in 2016, the gunvernment’s fuel efficiency fatwa that decrees all new cars – and all new trucks – will achieve an average of at least 35.5 MPG goes into effect.

Italics added.DI graphic

A small handful of cars achieve 35 MPG or better … on the highway.

Almost no new cars average 35.5 MPG.

Hybrids like the Prius are among the few that do.

Those that don’t will incur gunvernment-enforced “gas guzzler” penalties – passed on to you, the car buyer. Your next new car may be slightly more fuel-efficient. But it will also cost you significantly more.

And in more than one way, too.

The federal fuel economy fatwa – Corporate Average Fuel Economy, in gunvernment-speak – is also choke-holding the auto industry to get rid of V-8s and even V-6 engines. Including those that used to be standard in luxury cars. For example, Mercedes will no longer offer a V-8 in the 2015 E-Class; the BMW 3 and 5 Series now come standard with 2.0 liter four-cylinder engines. Only the very affluent – and gunvernment capos such as Obama and his successors – will enjoy big V-8s henceforth.

DI graphic 2But back to the DI thing – and how it’s going to ding you.

There’s the additional up-front cost, of course. DI requires (among other things) a specialized fuel-delivery system with multiple fuel pumps instead of just one – including a high-pressure pump near the injectors. Extremely high pressure. In excess of 30,000 PSI (not a typo). The extreme pressure is the source of DI’s fuel-efficiency advantage. The fuel is almost ideally atomized, so almost perfectly burned – which means the engine uses a bit less of it to make the same power as it would have if fed the fuel by less efficient means, such as port fuel injection.

Which sounds like a positive thing – except for this one negative (and costly) thing:

Carbon build-up inside the engine.

On the tops (and stems) of the intake valves, specifically. GDI

In an engine fed fuel by a carburetor or throttle body (TBI) or port fuel injection (PFI), the gas enters the combustion chamber from above the intake valve, cooling it and cleaning off combustion residue (carbon) in the process. This is the purpose of the detergent additives in fuel you may have heard advertised by gas companies. You “drive your engine clean” – literally.

But in a DI engine, the injectors are mounted below the intake (and exhaust) valves. The fuel is sprayed directly into the cylinder. As a result, there is no valve cooling/cleaning effect. The valves thus run hotter – and are prone to carbon encrustation. As carbon accumulates on the valves, they no longer seat properly – that is, the combustion chamber is no longer sealed when the valve is closed. You lose compression (and power). The engine will begin to misfire – and (if the leakage is bad enough) its emissions will actually increase as combustion efficiency decreases.

But this will probably not happen until the vehicle is out of warranty – and has about 75,000 miles or so on the clock.GDI graphic 2

At which point, it will be your problem.

And it could be a very expensive problem, indeed.

To get at the valves – in order to get the carbon crust off them – it is necessary to partially disassemble the engine. The intake manifold (and all the attached parts) must be removed, then the cylinder head. Typically, most of the accessories (e.g., the water pump, alternator and other engine-driven components) must also be taken off first before you can even get at the rest of the engine.

It is a major job.

And how much is it going to cost you?timing belt job

Consider the cost of replacing a timing belt. Many late-model cars (especially imports) have overhead cam (rather than overhead valve/pushrod) engines that require periodic timing belt replacement. If you own one of these cars, you probably already know all about it. The job entails partial engine disassembly – and the cost is typically in the $700-$1,500 range, depending on the make/model of the car and whether you have the work done by a dealer or an independent shop.

But a timing belt job is a less involved job. Because the taking-apart process does not require removal of the engine’s cylinder heads, which house the engine’s intake and exhaust valves. If the heads have to be pulled – in order to clean the valves – you are looking at the R&R cost for that in addition to all the other taking-apart you had to do (or rather, your mechanic had to do) in order to get at the heads.

If a timing belt jobs costs you say $700, expect a “DI job” (carbon removal, possible valve/head work) to cost you more. How much more will depend on how involved the job turns out to be – and of course, who’s doing the job.Dear Leader

But cost you, it will.

This is a fact that won’t be touted in the advertising literature. The car companies will talk about the fuel-efficiency gains – which won’t cost them anything since they’ll be passing along those costs to you. But to be fair about it, you can’t blame them for this. Shit rolls downhill. The gunvernment decrees all new cars will average 35.5 MPG (or else)  . . . soon to be upticked to 54.5 MPG, by the way – and the car companies have no real option but to comply.

But they can’t comply for free.

Which is why the costs get transferred to us.

Throw it in the Woods?

If you want this train to keep on chugging along – and running over Clovers – please throw some coals in the fire.

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  1. This article sounds very biased and misinforming…
    Yes some DI engines had issues with carbon build up but these were quite effectively addressed years ago, and only limited to certain manufacturers such as VW and BMW. In fact Hyundai/Kia engines now do a double spray upon cold start up – one into the combustion chamber, and another onto the backs of the intake valves when they open. This heats up the Cat converter quickly while having a cleaning effect on the backs of the valves.
    I know of a 2011 GDI Hyundai Accent in New Jersey that has over 550,000 MILES on its original engine and transmission, and has never had any form of carbon cleaning or problems relating thereto.
    Fuel and oil quality are extremely important too. Poor quality mineral oils have more volatile compounds that can enter the PCV system and accumulate on the intake valves, and low octane fuel causes the engine to run richer, therefore increasing fuel dilution, thus increasing the volatility of the oil again.
    Pretty much 100% of GDI engines I’ve seen with intake deposits have spent their lives idling in traffic as well. It seems they can be held at bay with regular highway runs and occasionalhigh RPM driving. A good hard drive can even sometimes clean the valves enough to clear a misfire, as they start to rotate close to redline it cleans off the valve seats and allows them to seal fully again.
    If you have a GDi engine, don’t worry about these fear spreading rumours. Just make sure you use high quality oil and fuel (which lets be honest applies to any engine) and if you drive mostly in the city, make sure once a week a good hour run down the highway with some good full throttle bursts are a part of your preventive maintenance!
    Happy driving these great machines!

    • Not to mention any carbon buildup on the intake valves can be completely removed within an hour via walnut shell blasting… It’s becoming pretty cheap too!

  2. This article has some valid points but also ignores that valve-timing, oil catch-cans and improved PCV systems can largely prevent carbon buildup. Certain Audis and VWs gave GDI a worse reputation than it deserves. Also, the rattling claim is largely specious; GDI engines don’t sound like old diesels at all.

    And the whole angle that increased fuel-efficiency is a conspiracy against working stiffs is born of Peak Oil & AGW denial. Oil is FINITE, depletes in a bell-curve (fracked shale peaks especially fast) and we should do everything possible not to squander our one-time ancient energy bonanza. All the talk of “rights” and “freedoms” won’t override the laws of physics and geology. Protest something with an actual moral angle, not blind rebellion against anything that cramps your style a bit.

    • Jim,

      I’ve been reading about “peak oil” being imminent since the ’70s. Oil may indeed be a finite resource but the relevant question is: How much is left?

      Rant along those lines is on deck….

    • As to AGW, just look up the meetings in the 70’s of The Club of Rome, where they said climate change “would do” to get the public on board with the agenda. At that time is was the global cooling & coming ice age scare that they made mainstream fear.

      This is one single recent “magic discovery”. There are more in Alaska even bigger.

      An American Oil Find That Holds More Than All of OPEC
      Nov. 13, 2012
      By ALAN FARNHAM via World News

      Drillers in Utah and Colorado are poking into a massive shale deposit trying to find a way to unlock oil reserves that are so vast they would swamp OPEC.

      A recent report by the U.S. Government Accountability Office estimated that if half of the oil bound up in the rock of the Green River Formation could be recovered it would be “equal to the entire world’s proven oil reserves.”

      It really is all about the biggies getting it to $150.00 a barrel. Everything else since the Alaska pipeline was built in 1977 is propaganda.

  3. One 1997 Ford Expedition and one 2004 VW Touareg TDI diesel. Never going to give these two old ODB II monsters up. Plain jane simple V8 gasoline PFI engine and pre-urea tank V10 diesel engine. This was the pinnacle of engine technology and I hope I am never put in a position to buy anything post 2006… and ESPECIALLY post 2015.

  4. Sounds like the final step in the p-lan to elimanate used cars. Once it’s out of warranty…it is no longer economically feasible to own.

    Myu V-8 Town Car used to get 23MPG. Most people I see with 4 cyl.s are barely getting that, because once these modern technological marvels have some wear on them and have a few components which are not operating at perfect peak efficientcy….the MPGs take a serious dump- and you can’t fix it, ’cause you’ll never know what parts are causing the loss of efficiency, since they’re not busted…but rather just not operating at peak. And there are so many [needless] parts….just a few of ’em losing only 2 or 3% capacity, in conjunction with a few others…and blammo! – you have a cramped, slow 4cyl POS that will get 19MPG for the next ten years.

    Whereas if it were a carbureted vehicle…you could fix it with the turn of a screwdriver…or even if you had to replace ALL of the parts, it’d be cheaper than fixing one thing on the fancy technological marvel!

    I’ll stick to my 11MPG vehicles, thank you very much Al Gore & co. There is absolutely no incentive to ever purchase any of these modern monstrosities. (I guess I didn’t learn from the last time we “ran out of gas” in the 1970’s…. )

    • Moleman – “I’ll stick to my 11MPG vehicles”

      Hallelujah and Amen brother….

      Almost all my vehicles have been $20,000 (financed) – resale value ~$5000-10000 – 40mpg’ish. Flimsy, over complicated and not particularly practical (except for commuting). Lots of safety gear, most of which will be relocated to the trunk during a head on impact with an F350 carrying a ton. While the crash cage has improved dramatically, you can only engineer a light (by today’s standard) vehicle to deal with so much mass at impact. A 460 alone weighs about 1/4 of an ecobox.

      I drive less than most so fuel consumption is less of an issue to me so as they say YMMV. However, I still maintain that since a service (or two) on new vehicles can run over the cost of my entire truck, when you add up all the costs, fuel is not as big of a percentage of total cost as people think. Yes there is a warranty on new but don’t forget, that is factored into the purchase price too. And the taxes, and PDI and interest, and higher insurance (due to finance) and airbag replacement, and turbo replacement, and, and, and…….

      In 2035 I really doubt any of the 2010+ vehicles are going to be running as well as a 25yo vehicle of today, at least without replacing most of the moving bits at least once.

      • Very, very good points, Me2! Even my ’99 F250 is way too complicated- but still manageable, as it’s one of only two vehicles, and I keep my vehicles a long, long time. But the funny thing is, for all that added technology, it only gets 1 MPG more than the old ’81 F250 I had years ago…..

        I too drive very little these days. I live out in the country- and only go to town to shop/run errands maybe once every two weeks. I guess for the average schmoe who commutes 50 or 100 miles a day, the MPGs matter- but if they were smart, they’d change their lifestyle/where they live/work (No wonder the average American is spending 25% of their income on transportation!). I think all these “fuel efficient” vehicles are just encouraging people to perpetuate that kind of lifestyle. Where I come from originally (Long Island) it’s not unusual to see people who spend 4 or 5 houts a day just commuting….so they can pay their $12K a year property taxes. It’s AMAZING what people will tolerate!

        Sometimes I envy you guys with the hi-MPG vehicles…. I bought a little old car a while back which got nearly 30MPG…couldn’t stand sitting down there a few inches off the ground driving that thing that had no personality. It was just a “transportation appliance”. Didn’t feel so bad filling up my truck’s gas tank and spending $100 to do so after that. (And luckily, I sold the gas-sipper for a nice profit!). I love my truck…big…safe…comfortable and sitting up nice and high…so it may cost me a few hunnert bucks a year more to drive….it’s well worth it. (Plus, 90% of the time I need to haul a good amount of stuff/or big items when I go to town, anyway)- and these full-size trucks endure. Don’t see many 15 year-old Escorts still on the road…but ya do see plenty of 15-25 year old trucks still. That more than makes up for a little extry gas.

        But I’ll still be thinking of you and your sipper next time I have to fill up! 🙂

      • Some text was missing from above. Not sure why. The complete version is below.

        Moleman – “I’ll stick to my 11MPG vehicles”

        Hallelujah and Amen brother….

        Almost all my vehicles have been $20,000 (financed) – resale value ~$5000-10000 – 40mpg’ish. Flimsy, over complicated and not particularly practical (except for commuting). Lots of safety gear, most of which will be relocated to the trunk during a head on impact with an F350 carrying a ton. While the crash cage has improved dramatically, you can only engineer a light (by today’s standard) vehicle to deal with so much mass at impact. A 460 alone weighs about 1/4 of an ecobox.

        I drive less than most so fuel consumption is less of an issue to me so as they say YMMV. However, I still maintain that since a service (or two) on new vehicles can run over the cost of my entire truck, when you add up all the costs, fuel is not as big of a percentage of total cost as people think. Yes there is a warranty on new but don’t forget, that is factored into the purchase price too. And the taxes, and PDI and interest, and higher insurance (due to finance) and airbag replacement, and turbo replacement, and, and, and…….

        In 2035 I really doubt any of the 2010+ vehicles are going to be running as well as a 25yo vehicle of today, at least without replacing most of the moving bits at least once.

        • Jesus, something is F’ed up. Repost lost the same text as the first time.

          Apparently something in this won’t post.

          “For years I have listened to folks telling me how economically crazy it is to drive such inefficient vehicles. Funny thing is they never look at TOTAL cost of ownership.

          90’s F350 crew long 460 – $2500 (cash) – resale value ~$2500 – 9-15mpg. Solid and near zero maintenance required, simple and DIY when it is. Infinitely practical. Carries a ton+ and 6 passengers. 300,000km, still uses no fluids, all original bits other than water pump, alternator, brakes, tires and muffler.”

          Whatever. Just my brain fart anyway. Ignore.

          • Ah, finally, success, Me2!!!!!

            Heh…that reminds me: Years ago, I’d see all the car and consumer magazines always hyping the cheesy little new econoboxes- some heaping POS was always “Car Of The Year” (Once included the Ford Fairmont ROTFL- and the Dodge Omni- LOL!)- Point is, they were always the flimsiest cars, on which everything would wear out (especially the suspensions and bodies! -and forget about it if you lived where the streets were rough- like NYC!)- People’d spend thousands to save $20 or $30 a month in gas (when gas was $1/Gal)…and in 3 or 4 years, those cars were all in the junkyards.

            Meanwhile, all the full-size trucks I’ve had, last forever….almost never need a thing. I see friends and relatives constantly buying new cars, and making sure to get rid of them before the warranty expires- they live with car payments their entire lives…and the depreciation they suffer in one year, would be enough to keep me and my 11MPG trucks in gas for the rest of my life! -But they want to drive something “economical”-LOL! It costs a fortune to drive something “economical”!

          • Thank Moleman.

            Still not quite a success as some more was still missing. Ahrg.

            “Almost all my vehicles have been $20,000 (financed)” is entirely wrong and should have been this (if it posts correctly).
            “Any new ecobox – >$20,000 (financed) – resale value ~$5000-10000 – 40mpg’ish.”

            I by cars (and everything else) cash, never financed.

          • Ditto, Me2. I’ve never had a “car payment” in my entire life. Always pay cash- for everything, from a $125 car once, to a $10K car-carrier. (The $125 one was a ’78 Buick LeSabre I had picked up in the 90’s- clean and in good shape, but for a hole in the floor- I loved that car.l It even got decent MPGs with the V8…never did a thing to it, other than change the erl! -and drove it for 2 years. Now THAT’s economy!)

  5. Two technical points:-

    – You can push back valve heating problems with sodium cooled valves, first introduced in the 1930s when Rolls Royce was developing the Merlin aero engine (sodium in hollow valve interiors melts easily, and then it convects heat away efficiently as it is shaken by the valve movement).

    – Two stroke engines don’t need valves anyway, and with direct injection (and a little more scavenge air) they don’t have their usual fuel wastage/exhaust mixing problems.

    Of course, both of those approaches have their own costs and there are even better approaches that don’t use direct injection, but if you are going to have direct injection, then those solve the particular problems that were outlined here.

  6. GM and Ford have claimed that the DI valve fouling is caused by leaving the intake valve open too long and letting partially combusted fuel past the intake valves. They claim to have fixed this problem and I have not heard of issues with GM or Ford DI engines. VW/Audi and BMW seem to have the most problems for some reason.

    • Hi Matt,

      My main beef is the technology forcing. That is, cars – including powertrains – are being made preposterously complex (and expensive) for the sake of “returns” that are ever diminishing.

      How much does DI add to the retail price of a car vs. PFI (or TBI)?

      What is the gain?

      A small (2-3) MPG uptick.

      Is it enough to justify the cost?

      Even if there is no issue with carbon build-up, you are still paying for the new hardware and the added complexity axiomatically means that the odds of something going wrong eventually increase. And given the complexity, the cost to fix is apt to be high.

      It will almost certainly be a repair beyond the ken of the DIY/home mechanic.

      • Eric, all the low hanging fruit was picked long ago and no, for the average consumer the increased ownership costs are not worth the fuel savings because the extra components and repairs end up being more expensive than the fuel saved!

        But, from the fed nationwide point of view, an extra 2-3 MPG saves billions of gallons of fuel per year and that’s the perspective where the regulations are developed.

        • Hi Jlw –


          And now there’s a conflict between “safety” and “good gas mileage.”

          Cars have become preposterously heavy (e.g., subcompacts like the Smart car and the Fiat 500 that weigh 2,300 or so pounds) which renders them less fuel-efficient.

          So, which will it be?

          We could have fantastically fuel-efficient cars (and without the expense or complexity of DI or multiple turbochargers, etc.) if it were allowable to build them light.

          But the automakers are (effectively) forbidden (by economic considerations) from selling light cars.

          So we get “safe” but gas-hungry cars.

          • So waddya think about ‘start-stop?’

            My bet is that is the next mandated technology – IIRC there are already ‘start-stop’ equipped vehicles where it can’t be turned off.

  7. Mercedes were using gasoline injection in the early 1950’s. Their 300 SEL was incredibly fast, used a Bosch mechanical six-piston pump to time and deliver the fuel, though they did use port injection, not direct into the comubstion chamber. That three litre engine developed enough horsepower to drive the cars in excess of 150 mph… in 1953. At a more sedate cruise, they’d deliver well over 30 mpg.

    In about 1962 they develooped a downsized version of that basic engine design (down to 2.2 liters) and the same six piston Bosck mechanical port injection system and fitted it to their family sedan, a four door luxury car with a nice interior, manual 4 speed column shift or optional 4 speed automatic. The car weighed in at about 2800 lbs, heavy for the time (Volvo 122 tipped in at about 2100, also heavy, the VW Beetle at about 1800). Those cars would effortlessly cruise at 80+ mph all day long and deliver fuel economy in excess of 40 mpg at that speed. For a spacious comfortable four door sedan, that was quite remarkable. I had one, and wish I still did. The ideal would have been to fit that mechanical injection powerplant into the very rare station wagon (“touring”) coachwork built at the same time. No, the SE version was never offered in the T series. Sigh…. though it would not be much of a trick to do so. THAT would be quite the travel car. A station wagon that handled, was fast, and delivered in excess of 40 mpg………

    • I remember reading an article in an old issue of Popular Mechanix from about 1957-58 talking about the Corvette’s Rochester ramjet mechanical fuel injection system, which if I recall, was also available on the Pontiac Bonneville, as well as Chrysler’s ill-fated Bendix Electrojector system (whose problems were mostly caused by the wax-paper wrapped capacitors and resistors under the hood). This article predicted that by 1963, fuel injection would replace carburetors…what happened?

  8. The answer is to become a gov’t employee and get a gov’t issued car so you need not worry about any of this stuff or the cost or whether the fed is printing money or anything else.

    Gov’t employees are insulated from all of life’s problems the rest of us face.

    And all they have to do is show up for work in the morning and pretend they work for eight hours. It’s a great gig.

  9. Eric seems to have little, if any technical background. The carbon issue is isolated to one engine Ford makes because Ford is not very good at making engines and didn’t consider certain long-term things when designing here-said engine.

    I agree that the “rules” are going too far but the automaker can choose anyway they want to increase the fuel mileage of the vehicle.

    Ford is notorious for cutting corners on really important design elements that would only add a few bucks to the cost of the vehicle.

    The airbox design on their 7.3 diesel on SD trucks in 99 is one. The filter was too small and would plug up and suck into the engine. It took them over a year and several band-air fixes before they came up with a design that sort of worked. It wasn’t until 4 years later that they came out with an “upgraded” airbox that actually solved the problem.

    • No JLW–my BMW mechanic complains loudly and frequently about the carbon build-up he’s seeing on the new direct-injection engines.

      Mine’s port. I drop a couple bottles of SeaFoam into the tank and take it for an “Italian tune-up” once in a while–a quiet Sunday morning run, fast and hard, frequent trips near redline and sustained high speed.

      Gets the engine hot, forces lots of nice solvent past the intake valves and keeps them clean.

      That’s not possible with DI. And it’s already causing trouble on the new DI BMW’s.

      I wonder if this is why Subaru/Toyota chose dual injection on the BRZ/FR-S; that engine is both port and direct-injected.

      • Hi Meth!

        Glad to see you’re still around!

        On the DI:

        For me, the biggest objection is technology forcing. DI may have some advantages, but are they worth the additional expense and the potential problems?

        Absent government pressure to incrementally improve gas mileage, I argue it’s not.

        Government is pushing ever-more-diminishing returns.

        And we’re getting the bill.

        • LOL “rumors of my death” etc.!

          Just busy as usual, doing as many hours as possible at my current gig which is both pleasant, challenging programming, and lucrative….put away as much as we can before the whole fucking thing collapses.

          I miss you guys, and lurk whenever I have a free moment. The boy is now 3.3 years old and about as busy as a Formula 1 connecting rod.

          And YES–I love the technology, but I despise having it shoved down my throat at gunpoint.

          What I WISH we could get done–and I’m agitating for it with my local “leader”–is to have Texas nullify a host of regulations. If CO and WA can give the FedGub the middle finger with cannabis, why not make Texas the “Kick-Ass Car State”? Why not have Texas be the only state with toilets that fucking work? Or lightbulbs as big and hot as we want?

          It would lead to a Renaissance of manufacturing in Texas. 1800-pound cars that do 60 in 3.5 seconds and get 45mpg on the highway.

          Why not?

    • Ford wasn’t intentionally cutting corners. They just “bought-out” most of their senior engineering talent as a cost cutting measure…. It was pretty sad when outside vendors knew far more about how their components functioned (Fuel pumps and port injectors and transmission valve bodies in my case) than the company engineering team.

      It was sad to see all that cumulative knowledge and experience walk out to early retirement. And the recent stumbles and gaffs since then are a symptom of the young engineers who don’t understand why some things were “always done that way”. Sooo they’re relearning some lessons the hard & expensive way.

      Just deserts for letting MBAs count pennies over accumulated, priceless experience and knowledge.

      • Among programmers we often joke when someone goes into management that you have to look at their upper eyelids….to see the frontal lobotomy scars.

        Young MBA’s are a scourge, a pestilence, a tumor.

      • At a place I once worked the term we used was “The War on Talent”.

        Engineers are considered fungible human resources. The finance and other people who can’t make product but are good at the institutionalized behaviors and games of a corporation don’t know the difference between engineers and why one might cost more than another. All they care about is pushing wages down.

        And what do companies want? More H1B Visas to drive engineering wages down further.

        The work/reward ratio of engineering is way out of wack now. It’s getting worse.

        When an engineer is doing several different job functions working on multiple projects usually unlike things and being interrupted keeping production going… which is the way things are now… mistakes happen.

        • Yup–MBA’s firmly believe the 9-women myth…if a woman can make a baby in 9 months, 9 of them can do it in one!

          And absolutely; this idiotic idea that engineers are drop-forged bits of a machine permeates their thinking. However, the free market is not so easily fooled, reality eventually wins. The pell-mell rush to outsourcing has reversed dramatically after some large and embarrassing failures.

          I worked on the early prototype stages of a project at BP to re-write their gas pipeline management software. We wrote a killer prototype; five times faster than the competing team’s. It wasn’t the technology we used, it was the architecture we designed–flexible, scalable, and lightweight.

          BP decided for our technology…but put the opposing team in charge of the architecture!

          Then they outsourced.

          Six years and $190 million later they shitcanned the whole thing. Total, abject project failure. Nothing gained.

          Stories like that get noticed. When one department of BP wants to sue another to recover their investment, questions are asked.

          It’s well-known among programmers and managers who started as programmers that a good programmer isn’t 50% better than a mediocre one; he’s 10X better. It’s an enormous gap in productivity…and managers who recognize it are rewarded with projects that work.

          Want another BP-like example? How about!

          • “a good programmer isn’t 50% better than a mediocre one; he’s 10X better”

            My wife is one of those, except the disparity is even more: she can quickly write major programs that are bug free, that others are simply incapable of writing. But she only gets paid twice what the chair-warmers do. I don’t know why she bothers, but I suppose pride of accomplishment is part of it.

            She’s also well aware of the outsourcing idiocy. I think the Indian companies involved probably use kickbacks to get those contracts. Let’s face it, upper management are often slimeballs, so there is no surprise how things work out.

          • @PJ–LOL indeed!

            Well, take heart. I know many guys who have “The Knack” who are making only 30% more than the seat-warmers. At least your wife’s paid closer to her real value.

            And you’re right; a big part of it is simply pride in accomplishment. It hearkens back to every artisan in history; we just LIKE doing it well. It’s craftsmanship and it’s very satisfying.

          • Eventually over-performing for the pay gets tiresome.

            Eventually I learned over performing pays nothing and gets the same results as performing just good enough.

        • I’ve always been bothered by the change from “Personnel department” to “Human resources”. An employee is no longer a person, but a resource…something to be used up and discarded. Much like furniture, supplies, etc.

          • It’s exactly what they intend. They want us to see ourselves as that which is why they changed the term. But at least it is honest. Which is why I use human resource in a derogatory fashion. I want it to sound as horrible as it really is, hopefully so it is rejected by people rather than accepted in the stealth like fashion it was intended.

          • Me too, Mike.

            It is one of those insufferable politically correct terms – like “diversity” and “reaching out” and “community.” All syrupy with faux overtones of caring.

            Makes me want to run screaming into the woods….

      • @ Shazaam – “Ford wasn’t intentionally cutting corners. They just “bought-out” most of their senior engineering talent as a cost cutting measure…”
        And what, pray tell, is the difference?

    • The 6.0 diesel ,which is an international engine, was aweful for carboning up the intake from the EGR system. But not allof them do it. Most of it is a fuel quility issue. The engines are designed to run on a minimun of 40 cetane. Some states require a certain rating. But most do not enforce it. I’ve seen some with 350k no carbon never been touched or <100k and corboned up so bad the ports in the intake are 75 percent blocked. All of the clean ones were people either from a state with stricter enforcement, use a cetane boost additive, or don't idle all the time. Diesels are no longer made to idle constantly.

    • Actually DI carbon is across brands. I first learned about with regard to Audis some years ago.

      As to engineering changes for problems, I could explain the processes, and why it goes that way so often. Usually poor info from the field, inability to replicate the problem, resistance internal to the company, company required testing, regulatory testing, etc and so on. Changing an airbox is a huge EPA deal. It would be avoided at all costs.

  10. Don’t take my head off, because I’m not a car guy, but how do operators of diesel engines get around the problem of having to take the engine apart to clean the valves? They haven’t been tolerating that expense and trouble all these years–or have they? If those operators are assumed to be mostly commercial, isn’t that an onerous expense?

    • Hi Paula,

      Diesels (compression ignition engines) may not have the same issue as a spark-ignition (gas) engine. The fuel itself, for instance, is much less volatile (and also has lubricating qualities, which gasoline – a solvent – doesn’t). Diesels also have a different operating range (lower engine RPM) and different power curves.

      Perhaps Powertrain Guy will jump in?

      • I think most of the problem of carbon on the intake valves is actually caused by the EGR valve. Of course something else that was mandated by the government. Until recently, big truck engines were not equipped with an EGR valve, hence no problems with intake valve deposits. The old Volvo tractor I drive at work has 1,070,000 miles on it and has not really ever had any engine work done it except a water pump. I do know that the new trucks require diesel exhaust fluid but I don’t know if they have an EGR or not. I will find out when I get one I guess. The new trucks do seem to have a lot of issues with the check engine light and emissions controls. Kind of like GM vehicles of the early to mid 80’s vintage.

    • I work on a lot of diesels, both the automotive types (precup heads) and equipment/truck (direct injection). The main difference in carbon buildup comes from the nature of the fuel itself, and somewhat from how it enters the combustion chamber. The fuel, as it burns, never forms the type of hard, abrasive carbon that gasoline does. It does build up somewhat, but it is a soft carbon, unstable as it builds up on heads, valves, pistons, etc. Since it is unstable, it only builds to a certain point, then sloughs off in blobs and begins to build up again. The super high compression ratios used in diesels (18:1 for a low pressure direct injection low speed heavy truck engine to maybe 22:1 in a high speed precup automitove engine) also results in far higher turbulence in the combustion chamber, adding to the forces that tend to break up the accumulating carbon. I’ve torn down Mercedes diesel engines with 300 to 400K miles on them, clean and nice inside, no carbon buildup. One other factor is the typical engine lube oil used in diesel engines…. VERY high in detergent action, these oils tend to provide an engine that does not build up “gunk” inside. I also find using those same oils in a standard gasoline engine promotes longer life, in part due to a cleaner engine inside. Engine operating RPM does not seem to be much of an issue relating to lack of buildup. The much slower turning heavy truck engines (redlines of around 1650 or so), some marine and industrial engines (900 RPM) don’t run any dirtier than do the higher RPM automotive and light truck engines (3600 RPM). In all of these, the much higher turbulence from higher compression ratios and greater power outputs contributes to the breakdown of any potential carbon buildup long before it becomes an issue.

      • Thanks, Eric and Tionico. My personal technical advisor thoroughly explained the difference between diesel and gasoline engines yesterday, and between his lesson, which was well-adapted to the meanest understanding, and your answers, I’m comfortably less ignorant on the topic.

  11. “…the car companies have no real option but to comply.”

    What the car companies should do is join together to go on strike and shut all their plants down in protest. Let the government scum deal with the fallout.

      • If they were going to do that, California would be the state they pull out of (have you *seen* the CARB requirements? Insane!). But the market is too big to ignore.

  12. A few things to correct. Gasoline DI pressures run around 3000psi, not 30,000 psi, which is where modern common rail diesels run. Also, the boost in efficiency does not come from better fuel atomization. In the past with PFI, the injector would typically inject onto the back of the hot intake valve while it was closed. This gave the fuel a brief period of time to evaporate before the intake valve opened and drew in air and fuel. Without this benefit, GDI has to atomize the fuel better than a typical PFI injector. Ultimately, the actual difference in fuel atomization in the combustion chamber just before the sparkplug fires is about equal between GDI and PFI.

    The main benefit to efficiency comes from two things. First, is the increase in volumetric efficiency: GDI only has to breath air whereas PFI engines breath 15 parts of air to 1 part of fuel. In other words, without the fuel in the way, we can now fit 6.7% more air into the cylinder. The engine now acts like it has 6.7% more displacement. Second, as the air is compressed, it is heated. Spraying fuel directly into the cylinder cools down this air charge. This allows the engine to run a higher compression ratio than would be possible with PFI. Higher compression ratios extract more work from the engine. All together, GDI adds around 10% efficiency increase over a PFI engine.

    All of this requires a mechanical fuel pump and the injectors are very noisy compared to low pressure PFI injectors. There might be some additional carbon build up on the intake valve but it’s not bad enough to have to tear an engine down to fix. If you ever pulled apart a modern high mileage PFI engine, you would find the ports and intake manifold caked with carbon(from the EGR) with a small clean spot where the fuel sprayed on the intake valve. GDI would simply do away with that clean spot but the engine will still run to 200k miles plus. With modern cam phasing(variable valve timing), it is possible to do away with the EGR completely, negating the carbon issue.

    I agree the OEMs are being squeezed with conflicting edicts that drive up vehicle weight while asking for absurd levels of fuel economy. However, GDI would be the least of my gripes as it’s a way for the OEMs to gain an instant 10% efficiency, which is huge in terms of economy. The engineers typically fight hard for 1%. And with the phasing out of EGR, carbon build-up is a non issue.

    • I knew that GDI was much better than this article would lead us to believe. How about timing the fuel injection pulse? Anything to be gained there?

      • Better, how?

        An incremental fuel efficiency advantage (maybe 2-3 MPG) that’s hardly noticeable to the vehicle’s owner. At the cost of much greater complexity and likely much higher repair costs down the road.

        Here’s something to consider: Significant improvement in fuel efficiency (as well as performance) could be achieved without such complexity (and cost) merely be reducing the vehicle’s weight by a few hundred pounds.

        • A ten percent increase in fuel efficiency across the fleet is nothing to sneeze at. And as you say, weight savings are a crucial part of the fuel saving formula. So I’m thinking the winning combination will involve both GDI technology and serious weight reduction.

          • Hi Mitrick,

            I agree, a 10 percent fuel efficiency gain is impressive. But at what cost? In particular, down the road service/maintenance? Those costs may very well negate the fuel efficiency savings. In any case, it’s far easier – and much less expensive – to build a light weight, fuel-efficient car. There were cars back in the late ’70s and early ’80s that achieved better mileage than most direct-injected modern economy cars… and they (the ’70s and ’80s cars) did so with carburetors.

            And they were able to do that because they were light.

  13. Climate change seems to be a ruse by which UN and UK thug havens such as NYC, Vatican, and London can slow down more productive populations and emerging economies to their slow growth rates.

    Rather like the Soviets would be doing if they had survived, they’d tell any who would listen that they keep their economy in an anemic stagnant shambles because of their concern for the environment. Not because they’re a militarized, production killing, authoritarian fiat banking police state.

    What can be observed scientifically is various small scale human cause planetary changes. For example, the beavers were hunted to extinction in Iran, now their rivers all run swiftly and unimpeded and their groundwater is disappearing at an alarming rate.

    The dustbowl was a prime example of human caused planetary change. Each of these kinds of problems can be observed and verified. And there exist mitigation and correction strategies for them.

    Measuring air temperatures across the world is unlikely to tell anyone anything meaningful. The solar weather is by far the most important factor, and no one has proposed any kinds of strategies to deal with the varying solar radiation that I’m aware of.

    It would make sense to have strategies for the amount of world ice doubling or for all of it completely melting, just as a measure of robustness and as a kind of world prepper provisions in order to be prepared.

  14. Well, yes and no.

    Yes it is more expensive, and yes there are unique challenges with this technology, and most definitely yes this would likely not be as prominent if it weren’t for CAFE standards, but it’s not quite as bad as it seems.

    First, the DI technology has been around for decades in diesels and they’ve pretty much worked out the kinks. It’s NOT a problem on the TDI engines, which tend to run for hundreds of thousands of miles trouble-free (but not necessarily the rest of the car). I would predict the gasoline version of DI, which is newer, will have problems, as you suggest, because it’s not as well established, but more because they’re having to combine it with other untested strategies to get better MPG numbers, and it’s hard to test engines for 100k miles and get them to market in time. Mostly, the carbon deposit issue is on the exhaust valves since carbon deposits come from burnt fuel. The valve overlap time does expose the intake valves to exhaust gasses a little, but since that’s when fresh air is mostly entering, it’s a minor problem at best.

    One thing I’m not certain about, but highly suspect, is that if you ever got air in the fuel line (e.g., ran out of gas), the ultra-high pressure injectors might just die a painful death and leave you stranded. Fuel injection is less tolerant of air in the line anyway, so I’d imagine higher pressures mean worse problems.

    Second, though better atomization is part of the advantage, most of the improvement in efficiency is due to the cooling effect of directly injecting cool gasoline into the relatively hot combustion chamber which subsequently permits the use of higher compression ratios. Higher compression means both more power and more fuel efficiency for the same amount of fuel used. That’s the primary reason we’ve seen large jumps in both horsepower and fuel economy in the past five years using the same displacement engines.

    My guess is that the industry would have eventually gone to DI anyway, but it would be more mature and efficient purely in response to consumer demand rather than government diktat.

    Third, and I need to confirm this, but I’ve read that the 35.5 mpg requirement is measured by a different method than the EPA estimated fuel economy numbers are. There’s a difference between the two such that the actual EPA estimates on the Maroney sticker in the window won’t be 35.5mpg but a bit lower in the real world. (since when has any government agency functioned in the real world?) It’s still a huge leap up, and will end up costing lots more money than it will save in fuel and emissions, but it might not be quite as big a jump, which may be why so many car companies, as you mentioned, aren’t even in the same ballpark as the upcoming mandate yet.

    There’s a similar apples and oranges comparison problem between Euro and US gas mileage figures. You’ll notice that many times Euro models of the same vehicle sold in the US gets much better gas mileage even with a bigger engine, often by 10+ mpg. While part of it is due to tighter emissions requirements in the US (the highest in the world, thanks to California), and part due to excess weight from the safety and emissions equipment required in the US, most of it is due to two factors. Firstly, the Euro measures are done differently than the EPA measures are. They use different cycles and processes when testin and calculating. For the record, the numbers are calculated based on independent subsets of data. No one actually takes an example of the model in question and drives around a predetermined loop of a houssnd miles or anything. Secondly, and more importantly, the Euro guys use a different measure for the gallon, the imperial gallon, than we do. There’s is actually a bit bigger, so they can go farther on a single gallon in an identical vehicle. A US gallon is 3.79 liters while an Imperisl gallon is 4.546 liters. This is the same “gallon” used in Canada, Britain, and most of the rest of the world, apparently.

    As a side note, there is a major “law of diminishing returns” in effect with gas mileage which the government regulations, and those pushing them, don’t recognize. An improvement of 5mpg is very different when you consider that going from 15mpg to 20mpg in a full size truck is a 33% improvement whereas going from 30mpg to 35mpg is only a 16.7% improvement. Thus in absolute terms of how much less gas up is burned and emissions generated, saving 5mpg on the truck is much more beneficial if you believe their stated goals (carbon emissions, greenhouse effects, etc). Every time the government forces higher efficiency standards, it costs more and more to implement while achieving less and less benefit. Rather than letting the individual consumer decide what is most important to them, and what they are willing to pay for that, they implement a one size fits no one policy. Which I think is more to your point.

    • Plus, I would venture to guess – that the EPA figures are also using 100% real gasoline (or the energy output of same) rather than the corn syrup spiked crap we have been forced to consume.

        • In Oz we have E5 (95 octane) and E10 (98 octane). Never encountered any efficiency problems with E5 and it allows me to hike the timing up a couple of degrees, but everything I’ve tried on E10, I lost a full 10% economy.

          Note that this is also the case with “performance” 98 octane fuels without ethanol. To make it work needs higher compression.

          • The ethanol stuff is not problematic (beyond the reduction in mileage) in newer stuff designed to burn it. The big upside (as you note) is it’s possible to run higher compression – and more aggressive ignition timing. But the older stuff – especially stuff with carburetors – does not like ethanol. Minimally (if the vehicle has a carb) the mixture must be adjusted to compensate. Which would be ok, if that’s all there was to it. But the alcohol attacks parts not designed to withstand alcohol and the moisture introduced into the system can (and often does) accelerate internal rusting (cars with uncoated/untreated metal tanks are particularly vulnerable to this).

            • eric, this is another reason I don’t understand fuel filters that remove water not being pushed harder. If the water in fuel were pure, nothing but H2O then I don’t see much of a problem with that. The other contaminates, minerals for the most part, do tend to build up on parts. I used to run methanol/water injection system on a carbed vehicle but “pure” methanol and distilled water were a must. All this system did was allow the engine to run more timing without having a hotter combustion chamber. It was good for performance and fuel mileage but you had to be careful to use the best fuel all the time with it(premium only and the highest number you could find). Back in the early 80’s you could still find numbers as high as 98 octane(rare) but 96 was fairly common then. Even in the 90’s I could find 93 for the boat but that went away too. I rarely see anything above 86 now and have my doubts of the accuracy of that. Put pump gas in a plastic bottle and watch the bottle turn milky and then watch it melt. That’s some seriously sorry fuel. It often doesn’t even smell like gasoline.

    • the Imperial Gallon has been mostly gone for some time. At most it might still be used in the UK. The rest of Europe is on the metric system, as has been Canada since about 1978 (I lived there when the litre replaced the imperial gallon). That does not dispel your statements that different calculations and test protocols are used….. in the old German shop manuals fuel ecomony is generally listed as l/Km. The Brits, of course, used miles per imperial gallon, not specifying the ImpG, as it was the only standard in England for liquid measure.

      You are 100% correct that the stupid One Size Fits No One model adoped by the gummint is nuts. Let the free market determine “who wins”. Maybe we’d again have 40+ mpg Volvo sedans again, like we did in the late 60’s and 70’s until the Bosch K Jetronic came out in 1971 on the 140 series. NONE of those injection cars could deliver more than 25 mpg, no matter HOW nicely yuo drove it.

  15. Back when I had the troublesome Civic, I spoke with a Honda powertrain engineer during a test-drive around town. He said (unofficially) that the new Earth Dreams direct-injection motors from Honda don’t have the carbon problem.

    Of course, they were just introduced, so it’s too soon to tell if that was a true statement for customer-owned vehicles. But given their engine-building chops, if anyone could do it, it would be Honda.

    GDI motors aren’t the only ones with carbon problems – VW’s TDI motors also tend to carbon-up. Not at the valves, but at the intake manifold, due to the EGR valve.

    • I have a 2007 Audi that has Direct Injection.To alleviate the carbon build up,I not only use Premium fuel,but every so often,sustain the engine to 3,000rpm for about 20 minutes(5th gear at highway speeds)to burn the carbon off the valves.IT WORKS!
      You will NEVER read this in the manual or hear it from the dealership or their affiliates!

      • Neal, since premium fuel has less energy than regular(it ignites at a higher temp controlling pre-detonation for higher compression ratio engines) I’d be interested how that’s a plus. I’m guessing an over-size fuel filter that filters to a smaller micron size and possibly filters out water would be of a great benefit. Diesels used to always have drains in the bottom for accumulated water. If you owned your own rig, you’d drain it every day and they also have two filters for fuel with one managing a much smaller particle. This is the reason you’d have more water in your secondary filter.

        Due to the alcohol content in gasoline these days you’d think that instead of using additives to emulsify it with the fuel and run it on through the engine, just the opposite tack of filtering it better would be the better answer. Of course, that would increase maintenance and since 99.9% of the driving public knows virtually nothing beyond turning a key and hoping for the best, that’s probably not going to ever happen unless it’s a totally automatic system which would cost more but can be done.

        While “blowing” the carbon off is better than it building up I suppose, that carbon is very hard and scratches any portion of the engine it comes into contact with.

        I recall back in carburetor days that “sick” engines with good plugs and timing, etc. were often helped by running WOT for several miles or close to WOT if it got scary fast(YMMV in the scary fast dept.). You could see it coming out the exhaust from the cab and watch it cure up but not having that carbon build-up in the first place was much preferable and back then, the gasoline tended to wash the valves. eric kindly pointed out to me one day that DI doesn’t wash a valve so I’m not entirely sure how “blowing it out” would work on a DI engine. I’ll have to take your word for it.

        I can see this being a problem only for those who use gasoline engines(maybe, I’m not sure how the DI diesels perform in this category). I think the almost non-existent sulfur content in diesel now may lead to a reduced diesel engine life since the sulfur did help lubricate and keep internal temps down. Every diesel pump had warnings for vehicles not designed for ultra-low sulfur fuel when the change was made. I rarely use a commercial pump so don’t know if the warnings are still there. I did dope my older diesels more when that fuel was the only brew available then and continue to do so. Seems like I now see older diesels (big rigs)having more cracked head problems now and blown head gaskets.

        As an aside, I did notice Red Devil fuel additive seemed to disappear along about the time red dye was used to denote ag diesel(no road tax). That’s a shame since it worked well and you could tell your concentration by the color of the fuel. Now the green stuff is just funky looking.

        I have yet to have my fuel inspected at a DOT harassment. It’s probably a good thing since the tank of road diesel being dry will have me over there filling up at the equipment tank. C’est la vie.

      • I forgot to mention diesels used to always have a water separator in the fuel system. I don’t see this much anymore and the throwaway filters rarely have a drain for water either. I’ve wondered about this quite a bit too. Maybe someone here can shed some light on this.

        I can’t help but think that aftermarket fuel filter systems are more important now than ever, much like dual oil filter systems.

  16. So why haven’t we started the ptichfork-and-torches brigades?
    At what point do you say, “ENOUGH!”

    I am reminded of an old cartoon… Three panels, words tell the story.
    You can’t keep a good man down.
    You can keep an average man down for 15 minutes.
    You can keep Carl in a bottle….

    I won’t be Carl. Will you?

    • Yup.

      The “beast” gets 4 MPG, IIRC.

      But that’s ok.

      Just as it was ok for Stalin and his crew to have special highways built for their exclusive use.

      • The Beast is actually based on a Chevy Kodiak/GMC Top Kick truck (F-600 for you Blue Oval folks), so it stands to reason that it’s CAFE exempt.

        Which brings me to this: If Obummer and his ilk were truly worried about climate change and pollution, they’d request that their rides got better gas mileage. Better yet, they’d cut back on all their schlepping around creation and try using Skype once in a while. I’d loooove to see Obummer say, “In the interest of reducing our nation’s energy consumption and carbon output, I’m cutting back on state visits by 20 percent. I’ll be making more use of Skype and WebEx, and encouraging all federal agencies to do the same. I’m also commissioning a new presidential limousine that gets double the mileage of the current vehicle.”

        In other words, I’ll believe climate change is a problem when TPTB start acting like it’s a problem.

        • If they were really worried, they’d put an auxiliary power unit on the M1A2 tank so it doesn’t have to idle all the time to power it’s systems.

          But hey the rules never did apply when “National Security” was at stake.

          • Right!

            How large is Air Force One’s climate change “footprint”?

            Does Dear Leader really need a customized 747? How many square feet does one couple need? Don’t expect Dear Leader to turn down his thermostat.

            Not that it matters.

            After all, he’s not paying the electric (or gas) bill.

            We are.


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