When Should I Change My Car’s Oil?

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It’s a very common question – but it’s hard to get a straight answer.oil change lead

I’ll try to give you one.

It depends.

On your particular car.

And how you drive it.

First, let’s consider the car you’ve got.

The older it is, the more often you’ll need to change the oil. Especially if it’s older than circa late 1980s and has a carburetor (rather than fuel injection) and does not have a computer.

Carbs have many virtues, including adjustability and fixability (fuel injection components are generally not adjustable or fixable; they’re pre-set to work a certain way and you replace not-working parts with a new parts). But, they are sloppy with the gas. Carburetors are basically little metal (alloy, actually) boxes filled with liquid gas. The gas is held in a reservoir called a fuel bowl – and it’s from here the fuel (along with air) gets sucked by vacuum into the engine.

These fuel bowls are prone to seep and leak; liquid gas washes down the engine’s cylinder walls and other metal surfaces (taking with it the protective film of oil that would otherwise lubricate the moving parts) and ends up mixed with the oil in the crankcase.

Oil and gas – just like oil and water – is not a match made in heaven.Q jet fuel bowl pic

Reagan-era (and older) cars with carbs also do not have computers to monitor – and automatically adjust – the air-fuel ratio, to prevent the engine from running over-rich (too much gas in the mix) or lean (not enough gas in the mix). Less than optimum combustion means more combustion byproducts, which means the oil gets more gunk in it sooner. This, in turn, compromises the oil’s ability to lubricate (and keep clean) the engine’s innards. Which results in more rapid wear and tear… and so on.

An aggravating factor back then was the oil itself. By current standards, the stuff we put into our crankcases even 20 years ago was the equivalent of Folger’s Crystals vs. Starbucks coffee.

That’s why – in the past – the rule of thumb was to change the oil every 3,000 miles or so.

But cars built since the mid-1990s through today have fuel-injected engines. The gas is fed to (rather than sucked into) the engine in a carefully atomized spritz. There’s no reservoir of liquid gas sloshing around in a fuel-injected system to dribble into the engine; also, the  computer monitors and adjusts the air-fuel ratio for optimum combustion. If something’s not right, you get a “check engine” warning to let you know. Ignition systems are also much-improved (and engine build tolerances much tighter now than in the olde days). Contamination of the oil is thus much less – and takes much longer.injector pic

Oil quality is also much improved. Synthetic and semi-synthetics are now commonly prescribed. These offer more protection, especially under extreme conditions – and they maintain that higher level of protection for longer.

Result: Longer intervals between oil changes.

In some cases, as infrequently as once every 10,000 miles or even longer. Which is fantastic, especially given that some synthetics cost $10 (or more) a quart and even run-of-the-mill non-synthetic oil typically costs about $4-5 a quart.

But, you’ve also got to take into account how you drive.

If you read your vehicle’s owners manual (the service booklet may be separate) you’ll discover this – and specifically, discover something the salesman may not have told you when you bought the car: That the advertised long-duration changeout interval may not apply to you.

Because of the type of driving you do.legal contract

In the manual, you’ll usually find two service schedules. One for “normal” driving. The other for “heavy duty” (or “severe”) driving. The latter triggers a more frequent oil and filter change schedule than the best-case/long-haul scenario which may have been touted by the salesman (and featured in car company advertisements). The catch here is that most people assume that because they do not drag race or overload their vehicles, their driving falls into the “normal” category. But it may not. Short A to B trips, mostly stop-and-go driving, prolonged periods of idling the engine, prolonged periods of the car just sitting … these are a few examples of driving/usage patterns that can qualify as “heavy duty” or “severe” – and trigger the more frequent oil/filter changeout schedule.

So, remember: Don’t go by what the salesman (or service advisor – who is also a salesman) tell you. Check out the manual – and go by what it tells you.

It’s important you do so for the sake of your car’s longevity – and for the sake of your warranty coverage, which was carefully crafted by a room full of lawyers to give the company that made your car a plethora of ways to welsh on the coverage if something breaks. Keep in mind that almost anything major that could go wrong with a car engine can plausibly be attributed to an oil issue.check oil

And it’s not just the intervals that are important to keep track of. It’s also imperative to use only oil (and filters) that meet the manufacturer’s specifications. That means type – and weight. Use no other. If you don’t – or, more to the point, can’t prove you did – then you could find yourself holding a weighty bag. This means keep records – and receipts. Document every oil/filter change, most especially those you do yourself.

One last thing: It’s still just as important to periodically check the oil level. Today’s cars may not burn oil as obviously as they did back in the RRRRRRReagan years. But they all burn oil nonetheless. It’s a function of combustion – and though the amount varies by car as well as age, over time, the oil level will decrease as oil is consumed.

Never make the mistake of assuming your crankcase is full.

Know that it is.

Check it once a month, at minimum.

If not, it’s on you if something goes bang.

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72 COMMENTS

  1. Go by TIME rather than mileage unless you’re driving a taxicab or delivery vehicle. Six months or 7.5K miles is what’s recommended for my 2014 Ford Focus, which has a computer to “advise” when to do an oil change. The reasoning is simple: if you drive a lot of higher speeds on the highway, the engine is getting well warmed and turning revs; that keeps it as clean as it can keep itself. It’s ‘stop and go” and never getting fully warmed up that is hard on the engine oil and the engine parts. I’ve kept to strictly Motorcraft 5W-20 Synthetic Blend and the Motorcraft oil filter, not because they’re any better product, but keeping that to keep the engine warranty in effect. The incremental cost over the Walley World equivalent is cheap enough insurance against warranty hassles.

  2. My oil usually leaks out a bit and burns off some, so I can just constantly refresh it by adding more…no changing required. 😀

    • Hi, Ignatius!

      I know people who do that – and they seem to get away with it, too. Although I’m a risk taker when it comes to many things, this is one thing I’m cautious about. Probably because I’m so OCD about machinery and maintenance!

  3. Buddys dad had a ford ranger bought new. Gave it to his kid. Kid asked when the last oil change was. He said he has never changed it. Just added when needed. Truck had 110,000 on it. Ran for a long time after that for the kid. I have 190,000 on a cavalier. Changed oil 3 times. That is, i have it changed when its on the rack for new tires. Still runs like a top. I think the engine will outlast the body.

  4. Are there any special implications for turbo? I have a Subaru WRX, and I was warned by my old company’s fleet manager years ago that these cars “ate oil”. Sure enough it appears to do so. I have to top it off occasionally. I’ve asked mechanics why this occurs and have gotten multiple answers. One guy suggested that it could be due to seals that are leaking, but when I took it to another place, I was told the seals were fine, and the turbo is really the culprit. He said that if you don’t idle long enough before turning the car off, the turbo fan stops too abruptly and gets knocked slightly off center. Once this happens, small amounts of oil gets into it and burned up by it, and there’s nothing you can do but replace it. Interestingly he said not to be too concerned by it, and that I didn’t need to replace mine right now. I trust the guy, but I just don’t know enough to say whether or not it’s true. Does turbo generally have this issue?

    • Hi McSack,

      Turbocharged cars run hotter (and under greater loads) so oiling is particularly critical. And – yes – many (older) turbo models would suffer premature deaths from being run hard, then shut down – which cooked the turbo as oil was no longer circulating with the engine not running.

      This has apparently been addressed in the newer models, but if it were my car I would do exactly as you wrote: Let the engine idle for a minute or so after a hard run (maybe always) before shutting her down. It can’t hurt. I’d also use the best-quality synthetic available, too. Amesoil would be my first choice (and no, I am not a distributor, just a very satisfied user).

      Hope this helps!

      • mcsack,
        i am assuming you have a 3rd gen wrx and there are tech service bulletins for those regarding the turbo getting starved of oil due to an inline mesh filter. a mesh to decrease particulates but then it gets clogged and starves the turbo oil, sounds like damned if you do, damned if you don’t to me.
        see it on amsoil’s site. i suspect many rex fans just pull the mesh screen out.
        http://www.amsoil.com/mygarage/VehicleLookupPage.aspx?FromIndex=1&url2=2015+SUBARU+WRX+F

        eric,
        my prior turbo experience:
        I had a 1991 turbo mr2 back in teh day and the older turbos had issues, bascially running it hard and shutting it down immediately afterwards caused the oil to stop circulating thru the turbo so it would sit and boil due to the turbo temp and no flow pulling the heat away. it would then cake on and cause the turbo to basically aircool quickly, this woudl cause distortions over time. simple solutino was to let it idle for 30 secs to a few mins depending on driving “manners”. i went the lazy route and installed a turbo-timer and got 155k out of that engine before issues arose and i drove that mf’er hard (got it at 95k rightbefore i turned 17).

        i recently purchased a new wrx (very happy so far) and i am told new turbos are liquid cooled and because the fa20 engine’s turbo sits lower than the engine (gravity allows flow to continue after shutdown) and cooling system it does not require a turbo timer. i am still breaking it in soit isnt’ driven hard at all but would rpefer to not install a timer if i dont’ need to. you have anything to add regarding this, do stock audi turbo’s and vw’s have factory timers?

        my first oil change is free but follwing that i will do them myself and plan on using amsoil or royal purple. if i use amsoil and order it thru their site after clikcin on the link on epautos do you get a cut of my purchase or jsut a few pennies for when i click on the link regardless of whether i purchase anytihng?

        • Our Forester XT left us stranded at the mercy of the Minnesotans (thanks be to God). The screen was clogged. The dealer said they routinely take them out. An acquaintance, who bought our wonderful 1967 SAAB 95, said when I told him about the turbo, “Pennzoil should pay for all the damage they’ve done.”
          Our tractors all require a cool down idle and our tractor mechanic suggests the same for non-turbo engines. We got rid of the Subie which was junk anyway, requiring two handed shifts on occasion ; prolly because its previous owner was a female public defender in Chicago.

    • McSack, I doubt a turbo engine shut off too soon would shunt the turbo off-centre. That’s just impossible as the turbine is held in place by bearings that can’t shift. Go to another mechanic.

      Different engines use different amounts of oil. Even identical cars will use differing amounts of oil. No engine is exactly the same.

      • Thanks for the advice. Any idea what might explain the oil depletion then? If there’s a leak, then it’s not pooling up on the ground anywhere, but there’s a definite slow loss going on as I have to top off every 60 days or so. I do notice after driving for a while when it comes to an idle I can definitely smell the odor of vaporized oil.

        • Hi Mc,

          It is normal for all IC engines to consume a small amount of oil, which (over time) will result in a “low” reading on the dipstick. So, even if there are no leaks/drips, the oil level will go down eventually.

        • McSack, interesting how you smell oil but nothing left on the driveway. You might have a slow drip onto the exhaust that burns off. If nothing can be found to be leaking externally, it might be a crankcase breather hose with a split or.. but I’m just guessing.

          It’s like with my sister’s car. Very new but always smells like coolant although it never loses any. Probably residue left somewhere.

          Remember the turbo’s bearings and seals are just another area where small amounts of oil can get sucked into the engine, similar to valve stem seals etc.

          Maybe check the WRX forums on your oil usage patterns and see if this type of engine has some innate history.

        • Another thought..

          If you’re using the recommended weight oil, such as 10W-30 or whatever it uses, you can always use slightly thicker oil, such as 10W-40 or 10W-50 that don’t thin out quite as much when they get hot. Even 15W-40 which is a bit thicker initially.

          Just don’t go full 20W-40 unless you seek some advice whether it can handle that. There shouldn’t be a problem but modern engines tend to use thinner oils because clearances are tighter.

          • On older vehicles with worn engines I’ve found that 20W50 can work well. Not too good if you get really frigid winters though. (I’m talking about 1960s-1970s vintage iron. The new stuff seems to want 5W or even 0W oils.)

    • Hi Steve,

      I recommend using a high quality (and appropriate for the application) oil; then additives ought to be unnecessary.

      Example: I use Amesoil formulated with extra ZDDP in my old muscle car, because its engine is a flat tappet design and needs those additives, which are largely absent from most oils (including high-end synthetics).

      • Mobil 1 15W50 also has high ZDDP levels for flat-tappet engines, though it’s not one of their more popular formulations and may be tough to find. An interesting site for oil info is bobistheoilguy.com.

    • Steve, some oil “slick” additives are useful. I found some with PTFE (teflon) do pretty much what they say. Molybdenum additives are also good. Oil thickeners/stabilisers thicken the oil and help reduce it burning away, but it can only do so much if your engine’s crapped out.

      But beware those fuel additives! I can’t stress that enough. Fuels are designed to a certain standard with enough detergents to keep your engine clean enough. Early fuels were simply awful. They’d clog the works with wax, gum and sludge.

      If your engine’s already clean, there’s nothing an additive could do, except maybe in a diesel to reduce gelling in freezing temps.

      It might be useful to run a bottle of cleaner every 20K miles, but only if your car only ever does short trips, which clog up the cylinders and exhaust with deposits. Even then I dare say a cleaner might not be useful. Take the car for a fast run, say 50 miles or more to really heat up and burn out the deposits. Plant the foot into high load and revs occasionally. That usually works best.

      Those “octane boosters” are just garbage, mostly coloured kerosene. If you look into the tech of what an octane rating is, you’ll get it. Sure they’ll “boost” the octane numbers, but higher octane fuels burn slightly slower, reducing “ping”, but also therefore reduce fuel economy.

      The only way they can increase their claimed power is that if the engine already has sufficiently high enough compression and ignition timing that it can benefit or, such as avoiding the knock sensor backing off the timing because of pinging caused by crap fuel.

      I’ve tried many fuels and additives in many engines but one thing remains clear – I never got more power that I could actually perceive and, up to octane 95 fuel economy remains the same, but a switch to 98 and I lose around 10% economy.

      I’ve never had a high performance engine to try anything with though but for the average engine, just stick to 91 octane and avoid the “boosters”.

      One thing I DID have success with though, was a fuel pre-heater, using radiator or engine block temps to raise the fuel temp before induction. Worked great on my carby CBR1000 bike. There was a noticeable increase in power. It can be hard to do depending on your engine, but it might be good looking into.

  5. When there is no manual, what do we consult instead?
    Having never owned a new vehicle, by the Gary North theory, I’ve never seen a manual. I’ve always gone by the sleaze factor. When the oil starts changing color from the standard carbon black to the tan, the breakdown is accelerating, and it is time to reset.

    • Hi Bill,

      The info is usually easy to find online in PDF, CD or hard copy form. eBay, for example, is an excellent resource. I strongly recommend that one obtain an owner’s manual for every vehicle one owns; the information it contains is well worth the small cost. And if one intends to do anything more than the most basic maintenance work on one’s vehicle, I recommend buying the factory shop manual.

  6. My wife’s 2011 Honda CR-V has what Honda calls its ‘Maintenance Minder’ system, that supposedly monitors all driving conditions and adjusts the oil life, which is indicated in percentage of oil life left. There is also a series of displayed codes to other types of maintenance that should be done at each oil change. When I was younger, I probably would have said, “screw the Maintenance Minder, I’m going to do things how I think they should be done”, but given that I’m older now, and realize that I don’t know everything there is to know, I’ve decided to let her car tell me when to do things. Honda seems to do things pretty well, so I’m trusting them with this one. We bought the vehicle at two years old with 13K miles on it, and have put on 38K since we’ve owned it. So far, so good.

    • Hi Dan,

      It’s important to determine whether the reminder is “dumb” – based on mileage accrued – or “smart” – sensors capable of analyzing the condition of the oil in real time and notifying you when the oil needs to be changed based on that.

  7. What about running in?

    For my last 2 motorcycles I’ve followed the new-fangled advice to just run the engine hard from new – but change the oil the same day!

    Some racing teams do this, saying they have found they can avoid lengthy running in of new factory engines, by just thrashing them hard, then changing the oil there and then. Not only does it avoid hours of running in, they claim it actually gives better power and reliability.

    Your thoughts Eric?

    (So far I have done this on 2 little single cylinder dirt bikes, both seem fine)

    • Hi Alan,

      It would be useful to have objective data. comparing these methods. My immediate reaction, though, is that a race engine is not expected to live a long life. So long as it holds together for the duration of the competition – and makes good power during that time. But a car or bike you or I just bought? We probably want it to hold together – and run well – for many years.

      I’d therefore follow the protocols set forth by the manufacture unless objective data proved that there was no major risk of long-term durability issues by doing what the race teams do.

      That’s my 50!

      • Well this guy has a museum of pristine pistons, which is data of a sort..

        http://www.mototuneusa.com/break_in_secrets.htm

        I used the technique on my Malaysian-made MLE XTM-R 200, which pulled like a little tractor, with no problems at all for a year. Still running fine when I sold it last week. Just bought a new Kawasaki KLX and have done the same thing, so far no problems.

        A friend of mine, also with a KLX, introduced me to the concept. Said no need to run in, just change the oil after the first ride lah”

        (Malaysians tend to say “lah” at the end of some sentences, it’s rather cute)

        Bear in mind my bikes get hammered through the jungles and mountains of Borneo, powering up slopes and lots of engine braking down the other side, rinse and repeat for hours. I’ve seen a lot of 2 strokes seize up and watercooled bikes blow gaskets. Small, single pot 4 strokes seem to be best at shedding heat without breaking.

        • Hi Alan,

          Everyone has their own way of doing things!

          When I rebuild an engine (or have a brand-new one) I drive/ride the vehicle it’s in at varying but moderate speeds/loads for about 500 miles, then change the oil/filter and ride/drive normally.

          Your mileage may vary!

    • As a truck driver who has broken in brand new diesel engines and as a hobby engine builder I say the best way to break in a new engine is to drive it like it has 100,000 miles on it from the get go. Don’t abuse it but don’t baby it either. I have seen it both ways on identical engines and always the one broken in easy and babied for the first few hundred or thousand miles will never perform, either in power or economy, as one broken in as I said earlier. If I have built an engine I like to get it out on the road and accelerate hard a couple times up to the speed limit. Don’t over rev it but don’t be afraid to make the engine work either. That will seat the rings quickly and you will have a stronger running engine.

      As a truck driver when we got a new fleet of identical trucks some drivers would baby theirs for a few thousand miles and other drivers, like me, would drive them on the first day as though they had thousands of miles already. Every time the ones broke in easy never perform like the quickly broke in engines. There just was no way to get those babied engines to perform like the others either, no matter how they were driven or what we did to them. An easy break in period made a gutless engine every time.

  8. Oil additives wear out, moisture gets into the engine, combustion byproducts as well, these are things a filter cannot touch. Those are why I change the oil (standard oil) every 3000 miles on all my cars, old and older.

    Incidentally, I noticed that 5-30 weight oil started saying it was semi-synthetic a few years ago. This was certainly not the case before then. What % of modern oil is synthetic?

    • Hi Ross,

      Here’s my schedule:

      ’76 Trans-Am: Once annually with Amesoil (high ZDDP) or Royal Purple. The TA sees maybe 500 miles a year, so I change it according to time rather than miles.

      ’98 Nissan truck: Once every 3k or annually with good quality synthetic such as Mobil 1. This truck sits a lot, too and I usually get to 1 year before 3k.

      ’02 Nissan truck: Once a year or every 5k with good quality synthetic. This truck is used regularly and often reaches 5k before I get to 1 year.

      I use nothing but the best filters (Wix, K&N, Mobil 1) in my stuff.

      • Hi Eric,
        I wrestle with this on a 2005 Camry V6 that gets driven 1.6 miles each way to work 180 days a year (school teacher.) We try to warm the car fully when it’s freezing cold out, so most of the time it does get all the way to operating temp, and intend to get it up to 70 mph once a month, but still won’t hit 3000 miles in a year. I’ve been putting a high quality full synthetic in it once a year but wonder if that’s often enough. The oil on the dipstick always looks like the day I poured it in.

        Have you an opinion? Once a year or twice?

        • Hi DC,

          1.6 miles one-way is probably (almost certainly) not sufficient to bring the engine completely up to normal operating temperature – and even if it is, it doesn’t run the engine long enough to burn off accumulated contaminants. So, I’d do two things if this were my car:

          Change the oil every six months.

          Take at least one “long drive” (30 minutes or more) on the highway or at least, at highway speeds (55-plus MPH), at least once a month. Ideally, twice a month.

          Remember: It’s not just your engine that’s involved. You want lubricants to circulate through the rest of the driveline, too.

  9. OK, so your super duper filter, filters out any particle bigger than the oil itself. But gasoline that bypassed the rings is finer than the oil, so it doesn’t get filtered out and eventually breaks down or dilutes your oil, right?

    • Hi Clik,

      Absolutely. Condensation is another potential contaminant.

      These are two of the reasons why I prefer to err on the side of caution with regard to oil/filter changes. Better to be conservative than to push the envelope.

  10. Typo Eric:

    “This, in turn, comprised its ability to lubricate..”

    Should be “compromised”.

    On that note, I would also add that if your engine overheats at any time, such as blows a cooling hose or boils dry, the oil should be replaced as overheated (burned) oil can also have its lubrication qualities compromised.

    Although synthetics may be less susceptible to burning, it’s still a good idea considering oil is relatively cheap compared to engine wear.

  11. The day after I gave my hemi-headed Corolla the spray-N-wash treatment I ended up at the dealer with “check engine” light blinking and sputtering and popping – from water down the spark plug hole. While there I asked a couple of the mechanics what normally goes bad on my kind of car. They all pretty much said not much, but they did see major automatic transmission falilures. Why, are they poorly designed? No, not at all. Most people only change the engine oil and forget to do the same for the transmission.

    • Garysco, you’re lucky water didn’t end up in a wire connector somewhere. They can be a bastard to locate.

      In manual transmissions people often forget to change that oil, but in auto trannies, the diff oil ends up being forgotten almost altogether, because auto trannies require service, the diff is furthest from anyone’s mind.

      • @Rev – That was a weird one.
        After washing the engine I drove the car about 20 miles with no problem. You would think any leftover water would be gone by then. But the next day – sputter pop pop, all the way to the dealership 15 miles away. They charged me $90.00 diagnosis, then another 1/2 Hr labor to blow out the spark plug holes with compressed air. Ah, what the heck, it has 90,000 miles on it so throw on a new set of plug wires while you are in there.

        I keep waiting for the day it gives me trouble so I can sell it, but that was the one and only time that car has seen a dealership in 14 years and 170,000 miles, so I can’t complain too much. 🙂

        • Garysco, it sounds like any water ingress after the engine shut down evaporated in a closed space and seeped into some electrical wiring.

          This is why I cringe every time I see someone with the bonnet up and spraying high pressure caustic cleaners and water in there. High pressure is OK for the block, but wiring and connectors aren’t made for this, regardless if the connectors have rubber o-rings inside them. The problems can manifest immediately or shortly thereafter.

          About the only way problems can be avoided are to fill every connector with vaseline. The second best way is WD40 every connector inside instead of the vaso, but it’s never a guarantee.

            • Thanks Brent. Although not everyone has this on hand or can find it easily in some speed shops. Most sealers, lubricants and gaskets can be found in the bedside drawer IMHO.. 🙂

              It’s always a good idea to do something with all electrical connections under the hood from the day you buy the car, because moisture in the air will cause corrosion over time.

            • @Brent & Revolution. Good to know about the water/ vapor thing.
              As to dielectric grease, yes I have a tube of the stuff and use it. Especially on my bikes – as anything electrical is the #1 trouble point with them from my experience. But it was a bear to find an auto parts counter guy who knew what I was talking about . They kept trying to sell me little packets of light bulb stuff, which is not silicone. Finally an older guy at Napa said sure, here ya go.

      • My old commodore, since scrapped, had 411K kilometers on the diff, and it was only checked 5 times for fluid. Never changed. The least maintained system on the car was the most reliable. Never opened up the diff at all.

  12. I think modern vehicles (past 15 years) are so well assembled that the engines are virtually indestructible. The engineers design the powertrains with abuse and neglect in mind. If you change the oil within 10k miles you will be just fine for 300k miles.

    My last vehicle (92 Sentra SE-R) went almost a decade with low and dirty oil due to a leaking valve cover gasket. I would do daily 7500RPM runs to redline and the weekends were a mix of street racing and/or runs at the track.

    The only reason I got rid of the car was because of rust.

    • My father-out-law had a 68 Newport 383. I forget how many miles it had on it when his son finally rebuilt it. He changed the oil religiously every 3k. But one thing he NEVER did, even though it was recommended back then, was change the oil w/o changing the filter. Claimed it made more sense to change the filter and just add a quart of new oil than to change the oil and leave a quart of dirty, used oil in the mix.

  13. | “Oil and gas – just like oil and water – is not a match made in heaven.”
    _

    2-cycle engines directly mix oil & gasoline by design.

    So the chemistry must be more complicated than it first appears.

    • PtB is right Cassidy. 2 strokes are designed with the fuel/air mix travelling through the crankcase before being compressed in the cylinder because they don’t have cylinder head valves. This negates the possibility of a sump and therefore requires a small amount of correct type oil mixed in with the fuel prior to induction to lubricate big and small ends and piston rings.

      Some 2 strokes have this mixed in via an automatic oiler, but in general the oil’s mixed in with the fuel and then the tank filled. The correct fuel:oil ratio depends on the engine, which ranges from 25:1 to 50:1. It depends on the engine design and manufacturer.

      My older sister isn’t aware of such things and uses engine oil instead of the proper 2 stroke oil – in a haphazardly measured amount. Although this is effective for a short while, engine oil isn’t designed for this purpose and can produce more smoke and gunk within the engine.

    • Hi Cassidy,

      Yes, but it’s apples and oranges.

      In a two-stroke, a small amount of oil is mixed with the fuel charge and burned by design. Raw gas doesn’t pool in the lubricating oil because two strokes don’t have a sump.

  14. When I bought my TDI Sportwagen, they said change the oil every 10k, using a synthetic approved by VW. At that time (November ’08) that meant Castrol Syntec. Period. I’m sure the choices have expanded since then, but haven’t bothered to check.
    BTW, that 10k interval meant that the 36k or 3 years ‘free’ service that came with the sale only included 3 oil changes. 1st recommended tranny service, at 40k, not covered.

    • I keep looking at bypass oil filters for my TDI. They sound like they’re just the ticket: essentially “unlimited” miles between oil changes, 1 micron filtering, and change the filter every 25K. But then again, it might be overkill too.

      • Eric G, this is anathema to many on this site. For what reason other than ignorance I can’t say. Big rigs and big equipment have used bypass filtration for more than half a century. Luberfiner used to be THE thing in big rigs but now companies have expanded to include in-house filtration systems. Since it’s been fairly well proven that it takes a 5 micron or above solid to scratch an engine part, filters that remove everything that small and below are ideal for bypass use.

        Amsoil uses nano-tech filters that can hold up to ten times the amount of pollutants that other filters can although some are much better than others. If you really want an education just go to the Amsoil site and they will supply you with reams of material(in your hand, not only on line)showing what they have found.

        And as far as using a specific brand of oil, they have fairly much written the book via legality in courts that allows you to use any oil that meets or exceeds the oil mandated by the manufacturer.

        So when a company says you must use one brand of oil and forsake all others it won’t hold up and they know it. They simply use their corporate muscle and public ignorance to keep people using “Honda” or “Mercedes” or whatever oil the corporation says to use when in fact, you can use any oil that meets or exceeds those specs.

        If you want to use something like Amsoil, and I say this because they’re the only ones that have taken this to court, and the company says No, you must use Our oil, then Amsoil will get a lawyer on the line and “line them out” so to speak.

        Amsoil has vehicles with signs that say This Vehicle Never Changes Oil. What they mean is there is never a complete oil change. You must change the filters and add make-up oil but that may be all you ever have to do on an engine. You can have your current oil tested and that will indicate when it should be completely changed and on tight engines, that will be never using a full-flow and bypass filters of the right type together. Sure, you will eventually replace all of the oil but it’s mostly determined by how long you can run the same oil and how long each filter change increases that length of time. Not only big rigs but car and light truck engines can go half a million miles without a “full” oil change.

        If you really want to know as much as you can about engine oil, filtration and changes and how long oil can last, Amsoil is a good place to get some great info. Most other companies simply want you to believe you need to change oil every 3,000 miles for obvious reasons. That ain’t the truth though.

        Of course the air filter has a great deal to do with real world conditions of how often oil needs to be changed. Some products let no discernible dust into an engine, others, not nearly that good. There is a certain company that makes “performance” air filters that suck as far as being good air filters although they may flow a lot of air. An open plenum flows lots of air too and that company with a K in it’s logo is nearly as ineffective in some models as an oiled sock.

        • Eightsouthman,

          Not everyone wishes to add an oil bypass system to their vehicle or wish to take the time to analyze their oil to determine the optimal time/mileage for oil changes.

          Eric_G,

          If you want people knowledgeable about using bypass filtration in a TDI check Freds TDIclub. IIRC, some TDIs cannot fit a bypass system without modifying the hood.

          • TDIclub is where I found out about bypass oil filters. After I followed the rules on the “break-in” sticky thread and have NO oil consumption, I know that’s the place to go for advice.

            But they are a little obsessive about their cars, hence the question about filters.

        • Hi Eight,

          Probably, different “rules” apply to compression ignition vs. spark ignition engines. Diesel engines get lubed to some extent by their fuel, right?

          My position with regard to oil/filters is to err on the side of caution. A bypass system and just changing filters and topping off may be ok. But I’d never experiment with it using one of my vehicles! Well, not one I cared much about, anyhow.

          (And I am a fan/user of Amesoil, by the way).

          • eric, I wasn’t speaking of different fuels. I’ve installed a bypass filter on an Accord and a Lexus. Indications on both those cars tend to support the “never an oil change). Diesels are prone to have a great deal more particulate in their crankcases simply because of high pressures in the cylinders since they’re turbo-charged.

            There was a time when you could count on diesel to lubricate but since the sulfur has been removed it’s become dicey for older engines that were built with that in mind. Now diesels have more places where oil is sprayed for lubrication than previously.

            On a side not, it was once figured out the sulfur industry would tank if all the sulfur was removed from diesel fuel as well as gasoline. Well, we’re there and sulfur companies are doing ok I suppose since they’re still appear to be going strong.

            So what happens to that sulfur removed at the refining process? Is it exported? I see a lot of tankers headed for the coast these days.

            Anyway, back to the original subject. By pass filters commonly removed particles down to 1 micron and that leaves oil dang clean. The deciding factor as I understand it is how long it takes to use up the additives in the oil since synthetic oils are better simply because their source, mineral oil, is a better lubricant. I wouldn’t say there is no benefit to paying $20 every now and then to ascertain how the oil is holding up in a particular engine. I think we are progressing in that direction though simply by the better filters available and much longer service intervals.

            I’ll change oil as often as I need to and in some vehicles I’ve had, that would be every 1,000 miles. I chose to not use synthetics in those too. Also, those were abused engines before I became the owner.

            I wouldn’t say there’s a hard and fast rule about oil changing either.

              • Various nutritional supplements use the sulphate form of various compounds, primarily those used to ‘lube’ your joints. But that would be miniscule.
                Some farmers that test for trace elements as well as the big 3 (NPK) will use some sulfur as fertilizer.
                Perhaps the most interesting use is in making black powder.
                Of course there is always good old H2SO4.

                  • Dear Rev,

                    I know what you mean.

                    I can see both sides.

                    I went to elementary school in Vancouver, BC, Canada. Later I attended junior and senior high school in the US.

                    I’ve gotten used to the US spellings, but I actually think the older British spellings are better.

                    Also, the British practice of putting punctuation after quotation marks makes more sense. Easier to remember because it follows in logical and chronological order.

                    The American practice requires anticipating the punctuation and is more laborious.

                    http://www.thepunctuationguide.com/british-versus-american-style.html

                    Quotations

                    American style uses double quotes (“) for initial quotations, then single quotes (‘) for quotations within the initial quotation.

                    “Economic systems,” according to Professor White, “are an inevitable byproduct of civilization, and are, as John Doe said, ‘with us whether we want them or not.’”

                    British style uses single quotes (‘) for initial quotations, then double quotes (“) for quotations within the initial quotation.

                    ‘Economic systems’, according to Professor White, ‘are an inevitable byproduct of civilization, and are, as John Doe said, “with us whether we want them or not”’.

                    The above examples also show that the American style places commas and periods inside the quotation marks, even if they are not in the original material. British style (more sensibly) places unquoted periods and commas outside the quotation marks. For all other punctuation, the British and American styles are in agreement: unless the punctuation is part of the quoted material, it goes outside the quotation marks.

                    • Thanks Bevin. The intricacies of language and spelling are really only clearly evident to those with degrees in the subject, but for spelling, you’d think that everything would be spelled “phonetically”, but that word itself is already phonetically redundant.. 🙂

                      I once had a conversation with another YouTuber, and he replied to one of my posts:

                      What’s a “tyre”?

                      It was obvious his English teachers at his U.S. school never noted to the class there were different spellings between English domains. I chuckled.

                    • Hi PtB. Most browsers and document software use U.S. spellings in their database, so you’ll always end up with a red underline when trying to use particular English spelled words. It gets rather annoying at times 😉

                • We’ve had to add sulfur fertilizer since the reduction in coal fired power plants here in Iowa. We use an additive in all our diesel fuel because our tractors and combine were made before the fascist ultra low (intelligence) sulfur laws were put in place.

                  • Don’t worry Fritz, once Obummer’s been assassinated and the country has rolling blackouts, the coal power plants will be back – just like ex-ultra-green Germany.

                    The only way to get around low sulphur diesel is to use additives at the moment, until the EPA discovers its folly and discovers ULD fuels are worse for the environment, considering the amount of sulphur volcanoes worldwide spew out – such as Jellystone Park for one teeny example.

                    One guy I spoke to said he uses a large block of lead in his fuel tank to replace lubricity, although diesels use sulphur for that. Not sure how well it works though.

        • VW never said you had to use a specific oil, just that it had to meet a specific standard. Since they wrote new standard when the ‘new’ TDI came out (2008) to satisfy the EPA anti-sulfur gods, Castrol was the 1st company to produce a product to the new spec – and only one when I bought mine in November 2008.

          • I don’t think that this is correct.

            See this Audio TSB for example:
            http://microsites.audiusa.com/ngw/09/media/downloads/pdfs/Audi_TechnicalServiceBulletin_1997-2012.pdf

            Not sure if that is still valid, based on date, and if they no longer do them.
            But they did have oils on a list that met their standards.

            As Eric points out, why risk a warranty rejection by given them an out? If I were the manuf, facing some high-price catastrophic claim, I’d do an engine oil analysis, determine it wasn’t an oil that met the approved standard, and then deny the claim.

            It’s not just legalese, apparently there are (some) valid reasons for this: not all the products are identical, even with same SAE ratings, and the ones on the list have been specifically tested to be fine.
            Doesn’t mean unlisted ones are not, may only be that an unlisted one wasn’t evaluated.

            Point is, why run the risk, plenty of choices.

            • Scrolled right past page 2.
              see top of p2 under Service it spells it out plain and simple:

              you must use an approved oil, no other is permitted.
              If you don’t no warranty coverage.

              So, there it is at least from Audi / VW

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