It’s taken as gospel that pre-modern cars, especially those made in America, and particularly those with big V8s, were “gas hogs.”
But were they, really?
And are new cars as fuel-efficient as advertised?
The answer may surprise you.
Modern cars have, in general, smaller engines. These are tasked with moving cars that are, in general, heavier than the cars of the past. So they often have to work harder – especially if they’re tasked with moving the car quickly. This has consequences.
I’ll give you a study in Now vs. Then and you draw your own conclusions.
First, the Now – a modern sporty car with a very small (1.6 liter) engine: The 2016 Hyundai Veloster R-Spec.
I picked this car because it’s almost a direct comparison in two critical ways – the power it makes and the performance it delivers – vs. the car I will use to represent Then.
The great pumpkin, my 1976 Pontiac Trans-Am.
You may think it’s an odd juxtaposition. A rear-drive muscle car with a V8 vs. a front-wheel-drive sporty car with a very small four. But, despite the huge difference in the size of their engines – 1.6 liters as opposed to 7.4 liters – both engines produce nearly the same horsepower (201 and 200, respectively) and both cars do the 0-60 run in about the same seven seconds.
So, they’re different in layout – but similar in terms of what you get.
And the same goes for gas mileage.
According to the government, the Hyundai is capable of 25 MPG in city driving and 33 MPG on the highway, or 29 MPG on average. It may well be capable of that. But it actually delivered 20.7 MPG during my week-long test drive.
Which is still good for a sporty car.
But it’s not all that much better than what my 40-year-old old muscle car can manage. Especially when you take into account that the Trans-Am’s engine is literally five times the size and doesn’t have the electro-tech advantages of such things as direct injection and variable valve timing – both of which the Hyundai (like most modern cars) does have.
And the Pontiac – when new – did not have an overdrive top gear to cut engine RPMs at cruising speed. It came with a four-speed. The Hyundai has a six speed.
Yet the ancient Indian still averages about 16 MPG (the same-year Firebird Formula with the smaller 350 cubic inch V8 and a two-barrel carburetor and a three-speed automatic averaged 21).
So, about 5 MPG’s difference in real-world driving after 40 years of technological “improvements.”
Especially because my particular Trans-Am gets the same – or better MPGs – as the brand-new Hyundai. Because it has the one modification that’s worth real gains, MPG-wise: an overdrive transmission. I replaced the stock box with a modern one and without doing anything else to the car, it is capable of going about as far on a gallon of gas as a brand-new sporty car with a tiny four cylinder engine.
Many years have passed, but not as much has changed as you might think.
It’s true something new like the Hyundai is capable of giving better mileage – but not when driven as you probably would drive such a car.
Or at least, not as I would drive it.
To get the sporty acceleration of which it’s capable, it’s necessary to really wring that little engine out. Work it. If not, not much happens. The big V8, in contrast, is like a really big dude down at the gym. He has power to spare. Doesn’t need to work as hard to push the same weight as the smaller dude on the next bench.
But wait, you say. The 1.6 liter four and the 7.4 liter V8 both make about the same power – and they do. But the big V8 also makes tremendous torque: 330 ft.-lbs. at just 2,000 RPM vs. 195 ft.-lbs. at about the same RPM (1,750) for the Hyundai. It’s torque that gets a car moving; the more available, the better the leverage – the easier (more efficient) it is to get it moving. The Pontiac has to use less of its available motive force to get moving. And to stay moving. With the overdrive box, the TA lopes along at about 2,000 RPM at 75 MPH; the Hyundai’s engine is working harder (spinning faster) at the same road speed.
Anyone lucky enough to have driven a V8 muscle car knows all about it – about how effortlessly the big V8 propels all that steel and glass. You hardly have to touch the gas pedal. Which is why they use less gas than you might imagine – and have been told. At least, relative to the Now.
The car companies have added turbochargers (as here) to get more torque (and sooner torque) out of their smaller engines, but this adds complexity and cost and – all else being equal – the bigger engine still makes more torque. And – potentially, at least – can be surprisingly easy on gas.
The new (2016) Camaro SS – packing a 6.2 liter V8 that makes 455 horsepower (and 455 ft.-lbs. of torque) carries an EPA rating of 17 city, 28 highway. That’s (once again) only about 5 MPG off the pace of the four-cylinder Veloster.
But here’s where it gets interesting – sad, actually.
If the Camaro weren’t such a bloated hog – it weighs 3,685 pounds, despite all the advances in metallurgy, despite the use of aluminum for the engine rather than cast iron – it would get better mileage than the Hyundai does. The new SS weighs about the same as my ’76 Trans-Am. And the Pontiac has a cast-iron engine that weighs hundreds of pounds more than the Camaro’s aluminum V8. It also has a cast iron rear axle and a heavy steel (and bolt-on) front subframe. Steel wheels. Stamped steel control arms. Etc.
That’s the bedrock problem – weight.
It’s the reason why, despite all the technology, the cars of Now aren’t all that economical vs. the cars of Then. They’re too damned heavy. Because they need to meet ever-escalating “safety” standards that can only be met (economically met) by adding structure, which adds weight.
The tragedy is a car like the Veloster could – and should – be averaging 40 MPG and modern muscle cars like the Camaro averaging about 30. We (cue the Six Million Dollar Man) have the technology.
But we also have too much government.
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Since I fixed the exhaust manifold gasket leak on my Excursion (gas) it’s starting to get up into the 10MPG range! Not bad for a 8,000 lb. vehicle with a v-10 that drives like a sports car. (Imagine if it had reasonable gearing, instead of c 4.30’s -She’d probably get over 15MPG!)
Do what they will to an engine, there is only so much energy in a gallon of gasoline.
Increased efficiency is the only way to improve milage. How much has efficiency of the total machine been improved?
Engine efficiency has improved; the problem is the engines are expected to pull more weight, negating the efficiency improvements of the engine. Most current compacts weigh as much or nearly as much as mid-sized cars did back in the ’70s. It’s ridiculous. My ’76 Trans-Am was considered overweight in its time, but it’s hundreds of pounds lighter than its modern analog, a new Camaro SS.
eric, another thing about new engines is the horsepower they’re expected to have…..whatever the hell for? since you can’t use it without suffering from some lowlife with a badge and I won’t expound on that….the lowlife’s that is.
Getting in a car or pickup now I feel like I’m ready to race. As a friend recently said, This would be a good truck if it didn’t have a fuckin 10 speed meaning he’d have more speeds. He likes 13 speeds but I prefer an 18 speed(17% difference in the last 8 gears) if I’m limited to a single gearbox.
Ford and Chevy had collaborated in building a common 10 speed transmission and Ford is making a 9 speed while Chevy hasn’t gone above an 8 speed. I just wish they’d make every one of them manual.
Well eight thanks ,it warmed up to 36 overnight and the crust is softening on the snow and the radial ice is leaving ,we are supposed to have pretty nice weather by the weekend.
Its a shame about the downfall of mighty GM , all it takes is a profit driven management without vision ,to ruin a perfectly good company(GM used to be a very smart and resourceful company ,I liked the way they got out of one onerous govt contract ) even though ,I was never a GM man , butI admire and respect their wares ,despite everything ,they still seem able to pull out some good coups ,now if they can start timing stuff right .
Hello Eric, I have commented on your articles from time to time. A general theme that emerges on this website, are new cars better than old cars? It recurs in the form old muscle vs modern muscle (2 threads if not mistaken), discussions on durability and now fuel economy. It is a debate I have had many times with people at car shows and swap meets. I drive two cars at present, a 72 GranTorino with a 351 Cleveland 2bbl model engine, and a 2005 Chrysler Sebring, and I am constantly thinking about comparisons as I drive them. Both cars handle and drive really well, especially on the highway. The Torino, now equipped with an Edelbrock 4bbl, Edelbrock intake, and headers, but otherwise stock doesn’t get as good of mileage as the Sebring, but feels like it has a lot more power, especially at interstate speeds. The Torino with a 100K on the odometer also gets better oil economy than the Sebring with 70K. The Torino goes 3K miles between oil changes with no discernible loss of oil, in contrast with the Sebring which uses a quart every 1500 miles or so. As the Sebring did not use this much oil when new, I have concluded it’s increased oil consumption is a sign it’s engine is wearing out. I like the modern conveniences of the Sebring and the fuel economy, especially for long road trips. Cup holders are great inventions. But is the Sebring a better car? Ummn… I am not convinced. I think it is found lacking in the quality of construction department.
I’ll state my thoughts another way Eric. I saw the movie Bullit again two nights ago. If this were a tail of two car lots, one selling new 1968 model cars, like some of the beauties in the movie or a lot next door selling modern stuff, it’s pretty likely I’ll be looking at the 68s. Perhaps there would be enough cost difference because of the absence of gov’t regs that I could purchase me a nice Charger with a 318 for daily driving and another like the one in the movie, with a 440, so I could have some fun. I’ve driven two vehicles with 440s. It is a fun engine. If I’m able to buy a car in heaven it will have a 440, god willing.
Thats why I am sick and tired of those piss pot standard engines ,My Dodge Dakota V6 gets almost as good a mileage as the V8 model (WTF ) ,but where they get you is the extra cost for a more desireable engine (they didnt even offer a real good v6 for the Dakota ,even though they had several )so no more Mopar for me (I should swap a 5.7 Hemi into the Dakota so it would get decent mileage compared to the 3.7 Powertech V6 ) Good Grief.
Eric are you forgetting the diminutive Ford 3.5 ecoboost has 420 lbs ft of torque(213 cid ) but where are the gas savings ?.I have said it before ,I would sooner have 300 # less weight .then 10 extra horsepower ,my Dodge Dakota fails miserbly on both counts.it only has 235 lbs ft of torque and weighs close to 5000 # with me setting in it So you can imagine the adventure of trying to merge on the freeway with it
A friend had a dead Ford Ranger 4 banger and a good 302. Next thing you know he had a tire eating Ranger that wasn’t picky about what gear it was in.
Kevin, hemi…hemi….hemi….how bout a 426?
Ok Eight ,I also have a friend that did that .A 426 would get me killed in short order ,a 5.7 is a very doable swap in the lead sled Dakotas ,not to mention the fact that a 426 would harder to find then a 428 SCJ (COUSIN HAD ONE OF THOSE ) or a 427 SOHC .
Actually ,I am thinking of trading ol ‘ ” Blanco Chin ” on a ” Santa Cruz ” when they become availible ,with either the turbo gas motor or Diesel engine (Diesel Blue ) doesnt scare me
Hope this finds you in good weather ,sure is crappy around here ,pushed snow all day yesterday Had to drive around a stalled Sysco rig on the Mtn when I was headed to my route .
Kevin, we had beautiful weather yesterday with a high of lower 70’s and expect more today unless the wind howls. Hope you have a better one today.
You could also say that the new cars are doing pretty well considering that they have “everything”: good gas mileage, safety, low emissions, reliability, comfort, etc….
“they have ‘everything”’ – right, they have it all, whether you want it or not, and none of it is optional, except in the sense of ‘take it or leave it.’
But their gas mileage is actually not very good, all things considered! The best of them average in the 30s; which cars were doing back in the early ’80s.
I’ll give you “safety”… but you can have that! 🙂
T like electric windows, no A/c two seats and 2100 lbs max.
Would it not be a great thing for Ford to do a concept strippo car to show what can be done at 1800 lbs?
I doubt Ford or any other major car company will ever do such a thing – because it would run contrary to Loving Big Brother. All the major companies have essentially “partnered” with the government; accepted the “safety” regime and all the rest. They have done so because they have decided it is easier to join them than to fight them and because by joining them, they can more effectively throttle possible competitors (regulatory capture).
always enjoy your articles. I worked on the Plymouth Fury III with 440 magnum engine etc. of the ’70s. Those oldies, pre-computer and sensors days, were easy to work on. You and I could tune ’em up etc. Now I’m afraid to touch anything under the hood for fear of breaking something. But I can still work on my 2001 Ford Ranger v-6 going on 238000 miles! And still gets 18 mpgs with an overload of tools and my fat ass.
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My old Rambler 660 Classic with the 327 V-8 and three speed stick with electrically operated overdrive would get around 22 mpg or so on the highway. About two mpg fewer than my Subaru, but with twice the power.
i think that too many equate horsepower and torque with performance.
i once owned a 1972 lotus europa big valve twin cam.
a lovely vehicle. in twisty bits would clean big v8 corvettes.
and would get 40-50 mpg in that era. problem was it wanted good high test gasoline. oddly, it loved high octane avgas. which i could supply.
car was light. 2,100lbs. epa, dot hated it though.
i always thought it was the future of vehicles. light. highly maneuverable. and a great deal of fun to drive.
i miss it. sort of.
A remake on that Lotus engine with deeper dish pistons would set the compression ratio down to about 8.5 or so, yes, drop some power but let it burn today’s regular petrol. Rework the spark advance curve to better suit the octane rating of the lower grade petrol and you’d likely find it still delivers close to the same 40 mpg, but on the low grade fuel,. Sure, you’d lose the high end performance of the higher compression ratio works engine, so it would develop a bit less power in the twisties. It would still be light years ahead of that Veloster…. or most of what else passes for a performance car today.
The empty weight of my 1968 Oldsmobile Delta 88 was 3,950 lbs, for crying out loud. The Camaro weighs that much with two people in it.
The monstrous Olds Rocket 455 made 310 hp at 4,200 RPM and 490 lb./ft. of torque at a lazy 2,400 RPM…and that’s for the standard 2bbl model. Mine had the 4-bbl, which made 375 hp at 4,600 RPM and 510 lb./ft. of torque at 3,000 RPM. I also made some minor mods (Pertronix Ignitor ignition, 268-degree cam, dual exhausts) that likely put the output at 390-400 hp/525 lb./ft of torque.
The Turbo-Hydramatic 400 and the 3.08:1 rear end certainly held back the full potential of that Rocket…but there was many a time when I had to barely touch (or not touch at all) the gas pedal.
I truly believe that the reason that old Rocket managed to survive 40+ years and still have plenty of blast-off power into the 21st century is that it was never stressed all that much. The same cannot be said of today’s turbocharged 2.0L and smaller aluminum engines. They run hotter and at higher RPMs, and are working pretty hard most of the time.
Although they’re not sputtering and smoking after 50,000 miles like many the V8s of yore, it’s highly doubtful they’ll last even 15 years.
And, there’s this: An old school V8 like yours (and mine) can be completely rebuilt for a relatively small sum. About $1,500 in parts and machine work. That’s for the entire engine, oil pan to carburetor. And it can be done in the garage by anyone with a basic tool set and some mechanical aptitude.
With a modern engine, you have the engine… and then the fuel injection system (direct injection, increasingly), the computers, the sensors and the wiring… they are throw aways, after a certain point. Very few people are going to spend $6k-$10k on the parts and labor to rebuild something like the Veloster’s engine when it gets tired. When the Veloster itself is worth maybe $6k.
Appliances, like a toaster or a microwave. You use them until they stop working and then you toss em and buy a new one.
Not to mention that production of these new fangled devices requires energy and materials, which contributes to (cough cough) emissions and coal/oil burning. The lower lifetime of these vehicles also means non-optimum use of the materials and energy that went into making them. Typical result of tunnel visioned bureaucrats making technical decisions.
But cars would last too long. The only thing in the US economy that’s been decent for any industry in the last decades has been car sales and look how expensive they are now and how short their lives will be. I’ll be as likely to finance a new car for 8 years tomorrow as I ever will…..and I worked 3 days last month. I can show you old towns that never got very large, maybe 3000 people and are considerably smaller now. Nearly every house is a trailer house with $40-70K vehicles outside, not even a garage or carport. To me that says a great deal about the mindset of people these days, not much mind and a lot of set.
Eight, you forgot to mention one of the best growth industries un the USA… the firearms industry. Near exponentioal growth since the kinyun ascended the throne, no end in sight, and they are building better and longer lasting and more accurate guns than they were 20 years ago…. and that does not even factor in the “consumables” part of the industry.
And they are working on a “Cash in your Clunkers” program for the firearms….
Under guises of mental health, mental disability, “predisposition to violence,” etc, etc, etc.
If you don’t love Dear Leader, you’re incompetent and insane.
If you went to fight for your country, you’re incompetent and insane. (Unless you join the police, then you’re re-armed because Government Says.)
Which makes me think (despair) that no one really gives enough of a flying rodent’s rear to actually work on the hard (dirty) part of preserving the tree of liberty.
And the Hyundai gets 20MPG in the real world when NEW. What will it get in a few years when things are a little worn, and things are not functioning at optimal levels?
The T/A is still here 40 years later. It’s doubtful that the Hyundai will still be around in 10 years, ‘cuz once the warranty’s expired, it’s economically unfeasible to drive.
I think that is the true purpose of all these idiotic gov’t meddlings with cars: To eliminate used cars, and greatly reduce the number of people who can remain autonomous, because soon, only those who can afford to/care to purchase brand new or late-model disposable cars every few years will be able to drive.
Shoot, an old Falcon or Fairlane with a 6 cyl. would blow most modern cars away, MPG-wise, and be economical to maintain forever.
My own car-buying philosophy is: If I can’t fix it, I don’t buy it. It’s already getting hard to find computers and electronics for late 90’s/early 00’s vehicles. A friend needs a new ‘puter for his 99 F350 dually 4×4. Has to send his old ‘puter away to get rebuilt.
Time to dig up the circuitboards and hand-wire.
Although Radio Shack doesn’t even carry components any more. WTF is wrong with us, that we need everything laid out ahead of time? If it’s not in a kit, pre-built, we can’t be bothered?
(Which isn’t a problem when you’re wealthy, speaking of the society, but is a REAL problem when that society gets real poor, real fast. The Ravaging Hordes will be seeking the precious “juice” fast enough…)
(sigh) Got up on the wrong side of the Rack today, I guess…
Shoot ,those old little Fairlane V8 s (221 ,260 cid ) would get high 20s mpg with overdrive transmissions,Believe it or not the last Caprice (waterbug style) with a 350 TBI ,was capable of mid 20s mpg cruising on hi test with comfort and room to spare ,if the govt is going to meddle they need to get their Ducks in a row(nothing worse then an unelected bureaucrat )
Shades of “Minority Report ” the police are using a computer program now called “Predpol” at Santa Cruz to predict crime before it happens ,said to increase arrests 50% ,while decreasing crime by 20% (is it just me or does something seem a bit hokey with that math? )
“bureaucrat” – need to check your spelling Kevin. That’s ‘burro’ (as in ass) then ‘crap’
Damn PtB, that’s burro scat, the r being silent. That’s what we need to build that wall on the “border” with, burro scat….and the US will pay a bounty for the real thing and who has the most? Yep, nothing like getting illegals to build a wall for illegals. It takes a “famous” mind to come up with “scat” like that.
All I can say is ,heh,heh ,
(maybe Hee Haw ?)
The police state is upon us .
You dropped an aftermarket override into your 1976 Trans Am. Maybe a few other little “tweaks” to its emissions equipment, also to improve efficiency, hmmmmm?
So to make this a fair comparison, shouldn’t you free Hyundai’s engineers to make a few aftermarket mods too? 😉
Other than the OD transmission, the drivetrain’s stock!
No computer. No fuel injection. A carb. No fancy ignition system.
A better comparison would be to find out how far the mileage of the Hyundai would fall if it didn’t have the OD box (but had everything else!)
I still think if we’re doing “then” vs “now” comparisons, both cars should be stock. Or allow each of them to make minor mods to improve the product. 🙂
Well, the point is that the old engines weren’t as inefficient as commonly believed.
The fact that I can get an old muscle car with a carbureted V8 to within a few MPG of the real-world gas mileage of a new car with a much smaller engine and that has computer controls, direct injection and an OD transmission is telling.
How much more mileage could I wring out of the TA if its engine had a TBI system?
“Well, the point is that the old engines weren’t as inefficient as commonly believed.”
No argument there…at least until the later 1970s, early 1980s, when tightening emissions regs got way ahead of technology. Those were dark times indeed.
Right.. Ford’s “feedback carburetter” of that era was a nightmare. I have given up on a number of those disasters, impossible to sort out correctlyh, and simply gone boneyarding, found a standard Holley 2 Bbl from early 70’s, bolted that on, and cured it all. Some of the Jap cars of the era used similar carbs, but at least thei not only did the original product development well, they were repairable and a sharp guy could sort them out.
I think Eric was looking more at how much govt interference has hamstrung the new cars, and he succeeded.
The auto manufacturers want to sell cars. Left to their own devices, they would come up with safe cars, fast cars, cars that are cheap to operate. Maybe even combine at least two of those factors. The market would decide, not bloated bureaucrats from DC that no doubt have chauffeured 6 ton SUVs to protect them and their entourages from the proles.
If you want them to be “stock” then maybe Eric should get rid of his radials and the safety, mileage and handling they offer, and go back to the bias-ply PolyglasGT or Firehawk tires his Bird came with? Also, go look for the original spark plugs and air filter, maybe see if he could still find SF/CC spec oil? Otherwise it’s not “fair”.
A more appropriate comparison than the one you’re asking for, Mike, would be to allow Eric to hang the best of the new technology on that Bird without the EPA and NHTSA crapfest that cripples everything today.
For quite a while now I’ve been wanting to take a 2nd Gen like Eric’s and add modern tech to it. Not the ubiquitous LS transplant, but a Pontiac 455 built with the best that modern tech offers. Aluminum block and heads with a roller cam and shaft rockers, updated combustion chamber, and a plastic LS-style intake with a single blade throttle body. The latest thermal and lubrication coatings on forged pistons linked by H beam rods to a lightened forged crank. Add one of the great EFI systems Holley currently offers that DIY guys can install and tune. Put in a 6L90 overdrive trans and tune that EFI for lean cruise. Bet your ass I could get 30mpg out of it at sustained 70mph between cities, while I’d be able to tow a dump truck out of a mud hole with all that torque.
Hi Ellis, I have also been thinking of doing something like this, but becoming self-employed is my number one goal at this time. I probably should keep my eyes open for a donor car now because the price for suitable rear wheel drive cars will probably go up, I used to have a ’73 Monte Carlo that I just loved. It wasn’t quite a sports car, but sports cars are already very expensive. I would probably be better off looking for a newer (than 1973) Monte Carlo SS or something similar.
In the past, I also had considered trying to build a car similar to the famous and rare Buick Grand National. I sure could use a bale of money right now.
Even though a Monte back then was a Chevelle underneath, they were a lot different inside and it was all to the good. My SS El Camino has a Monte interior with swivel buckets, a comfy ride and good handler since it had the trailer towing package and I subbed a bunch of T/A front end parts from the WS 6 package.
My ’73 had swivel bucket seats too. I would actually buy another one if it wasn’t rusted out or something. I traded mine off in Kansas in the late ’80’s, so I am sure that that car has rusted out long ago and probably been crushed. I don’t even see cars like that being driven around any more though. Still, if I find a first, second, or fourth generation Monte Carlo that is structurally sound; I may buy it. I didn’t much like the looks of gen 3. A Chevelle or Grand Prix would likewise catch my interest. I wouldn’t want an El Camino though. My F-350 is the only cargo-hauling vehicle that I need.
For people interested in learning the differences in generations of Monte Carlos that I had mentioned, go here:
“cargo-hauling vehicle”? The primary purpose of an Elco is not hauling cargo – it’s hauling @55!
Two contradictory directives of higher fuel efficiency and ‘safety’ issued to the automobile industry, and quite likely the bureaucrats at the EPA/DOT/XYZ agencies don’t even realize it.
“Two contradictory directives” – Make that 3, reduced emissions.
and not “just” rediced emissions, but reductions in specific TYPES of emissions. That adds a level of complexity that’s a real challenge. Further, they never stop to figure that if fuel efficnency is increased to a certain point, the concurrent reduction of EVERYTHING that goes out the tailpipe will reduce the pollution per mile to below the prescribed limits per whatever else they figure out. Burn less fuel you also produce less pollution. But gummint fewls can’t think like that.
“But gummint fewls can’t think like that.”
No need to say “like that.”
Weight factors in more during stop and go driving than in highway use, which is probably why all my cars that got excellent city mileage were flyweights.
’95 corolla 1.8L 5spd – 30 city/35 highway
’85 golf 1.8L 5spd – 26 city/26 highway (lol)
’90 something mazda 626 4cyl auto – 19 city/30 highway
’01 regal gs 3.8Lsc auto – 17-19 city/26-29 highway
’95 roadmaster 5.7L (LT-1) auto (2.56 gears ugh) – 16-17 city/22-23 highway
’87 Z28 not stock 5.7L t.p.i. (DIY conversion from a 5.0L I did in 1991) auto 3.23 gears – 12-16 city/20-23 highway
’87 ext cab S10 old school 10:1scr 350sbc w/comp 292h cam etc…, 700r4 and 4.11 gears on 26″ tires – don’t know or care what it got in town/ 18.5 mpg highway
eta: correction ’87 s10 – 17.8 MPG highway
also worth mentioning ’92 grand am 3.3L v6 auto 19 city/30-37 highway (mileage went way up if u kept it under 65 mph)
DBB, that grand am is similar to the cars some friends and I own(95 Cutlass Supreme SL, 97 Malibu, 96 Grand Am, they all got 28-32 mpg at 70-75. So where’s the big improvement except power…you can’t use? What speed does the EPA cycle use for highway mileage?
Very solid point about the power you can’t use.
And which most people don’t.
Every day, I roll up behind someone in a car or SUV with 200-plus hp (Camry-Accord type cars with V6s have 260-plus) gimping along at slightly over or slightly under the ridiculous speed limits. Which, except for highway limits – remain what they were 40 years ago when the typical car was a four cylinder K-Car with maybe 110 hp.
Now, I get why people don’t use the power they’ve got. The omnipresence of cops and the over-the-top sanctions that come with even a couple of “speeding” tickets takes the joy right out of it. Countermeasures such as radar detectors help – but most people don’t have them (good ones are expensive) and so most people just slow-poke along. They accelerate from red lights as if hypermiling in a Prius, with the car in the left lane invariably matching pace with the car in the right lane. Everyone goes slow. What’s the point of having all this power?
I’ve said this before, but it’s the automotive equivalent of everyone walking around with a gaudy codpiece… but unable to get it up!
“…it’s the automotive equivalent of everyone walking around with a gaudy codpiece… but unable to get it up!”
Kind of like the trend of people putting graphics, wings, loud pipes, fake hood scoops, etc on their cars but performance wise it might have a K&N filter and some overpriced 4 electrode gimmicky spark plugs. We get them at the dragstrip once in a while but they rarely do more than run test & tune and wonder why their crap is slow.
RICE = Race Inspired Cosmetic Enhancements
If everything doesn’t go south for me, The Plan is to upgrade the 455 in the TA just a wee little bit. The trick is doing it without screwing with the historical coolness of it, which for me means sticking with the iron heads and (of course) stock block. The OE heads are the weak link with these things. The aftermarket alloy heads flow serious numbers. But they are obviously not stock and – for me – that is a problem. The Great Pumpkin has survived these 40 years mostly intact and I feel obliged to keep her that way.
But, a hotter cam couldn’t hurt…
My $.02, try to bump the scr up to 9/9.5:1, select a cam for no more than 5500 rpm peak power and dump the 4 series gear for something like 3.08-3.23.
The big torque but slow reving 455 will pull just as hard with a taller gear. My friends supercharged (stock unported iron heads) 428 powered GTO runs the same ETs (low 11s/high 10s) with 4.10s and 3.00s in the back and he’s not the only one that uses a mild gear ratio behind a big pontiac motor to go fast.
Porting the heads would be a nice upgrade too, if the budget allows for it.
IIRC the con rods are also a weak point in poncho motors, did a quck search and found this:
Latech, Creech, and Cobalt know their pontiacs way better than I do. I generally stick to chevys because i am a tightwad….
With the iron heads, compression ratios much over 9.0:1 or so can be iffy on pump gas. These engines run hot – and the octane they need isn’t commonly available. It’s why Pontiac went down to 8-something (even the SD-455) for the duration of the ’70s. The aftermarket alloy heads dissipate heat much better and I’ve heard you can run 10.0:1 or higher on pump gas with them.
I had a 3:23 in my pumpkin but there’s a 3.90 in there now. Probably too much, but lots of fun doing rolling burnouts at 30 – or so!
almost all of the 70s motors were 8 something scr (or less), not just the ponchos.
If you get the quench tightened up (.040 ish) and keep the dynamic compression ratio around 8:1 you should be fine with those old iron heads.
You can push higher if you’re confident in your tuning ability.
A funny thing about heads. Aluminum is so much better for higher CR’s but in every case I know of, they’re much better flow wise.
You can take one of the aluminum heads from a stock Chevy engine and it’s a great deal better in flow than any of the HP iron heads.
Of course, the aluminum stock head for BB’s of any brand are nearly non-existent. I always wondered how the heads from that all- aluminum 427 from way back when would stack up to any brand new aluminum head from the later aftermarket. Back in the 60’s that aluminum bare block 427 was $3000, the price of a new car and it was just a bare casting. In ’76 I had a chance to buy 2 Ford side-oiler crate engines for $1500/each. I was broke and waiting for back surgery. Any other time……..
Aluminum does not always mean a better flowing head, case in point look at the 113 casting L98 corvette head. The flow numbers were pretty weak. Flow isn’t the only consideration, port velocity is also important. This is why you dont put 220 cc (intake runner) heads on a 350 c.i. truck motor.
In general, a modern head (especially aftermarket stuff) is always going to outperform any stock 45 year old heads you can find. Any exceptions i can think of pertain to chinesium castings that lack proper quality control.
The weak point eh? Well, Poncho’s had a few weak points including the crank, rods, heads and lack of big HP oiling. They corrected all those things for one year though, in ’73 they had a forged crank with some outside sourced rods, high compression(don’t tell anybody, clover would shit), a cam that wasn’t listed in the books with some better heads. They would shit and git. Too bad they lost their cojones after one year. GM was horrible about that. I had a Tonawanda 350 SBC in a Impala, ’69 vintage. It was all original with one type of lifter and tappet on the left side and another on the right side. This sumbitch ran like a scalded dog and last 200K and would have lasted no telling how many miles if it hadn’t been for that damned nylon timing gear. When I tore it down, it had chamfered oiling ports on the lower end. The crank, cam, and pistons and rods were not to be found on any GM parts book. I had friend who worked in the parts dept. and they’d just scratch their heads, You sure these are the right numbers? Yep, I was sure. GM did a lot of stuff like that. BTW, the block on that ’73 Poncho in the T/A was a one year wonder from what I know. Coulda, shoulda, woulda……crap.
The thing about Pontiacs is they were torque engines, primarily. Especially the 428/455. The blocks and cranks are usually very dependable unless you want to regularly spin the things over 5,500 RPM – which isn’t necessary. That’s what 327s and 350s are for!
Pontiac made many heads and some are (much) better than others. D and round port designs of varying chamber volumes and other design differences.
The SD-455 you mention was offered for two years – 1973 and 1974. It had the round port heads and a beefier block and other upgrades. However, any 400 or 455 will make a good and reliable street engine.
Again, just don’t rev the things as if they were small Chevys … and think torque, not hp!
The only truly flawed Pontiac V8 – as a performance engine – was the 301. But it was meant to be an economy engine, primarily.
Aye, a pontiac is not a chevy so don’t build it like one. It gets costly in a hurry if you want to get high rpm from a pontiac (and have it live).
Word on the street is if you want a badass poncho start with a 400 and forget the 455.
The firing order of a Chevy made a difference in making big power. The 427 would rev pretty well too. I’d argue that the Pontiac 307 was just a pathetic engine. The way it was designed left it virtually impossible to gain any significant hp. Seemed like that same 307 was used in some Olds. Of course I’m speaking of the worst years ever for power. Mid 80’s everything sucked bad.
My experience with those Pontiac big blocks was limited, and the memory of that period in my career is dimmed through the years, but I seem to recall something about heads from a different displacement big block having larger ports and valves, but being the same basic casting. Thus, with a little help from an electric gopher and the right cam, the other heads could signficantly increase airflow yet retain a neat stock appearance. I DO remember the old Ford 390 head swap… go find a pair from a worn out Ford TBird and swap those onto the 390 in, say, an F 350 and the right workhorse cam. You want power? Simply press on that little thing over to the right. Add the stock TBird four barrel spreadbore manifold, low power economy remains, but open uo those large economy sized secondaries and try and pull your head off the back of the seat. Fun stuff….
Pontiac made two basic types of heads, the D port and the round port. Either bolts on to any Pontiac V8 block except the 301. Some of these heads (earlier hi-performance castings) had larger (1.77 vs. 1.66, IIRC) exhaust valves. The combustion chamber volume determined the compression ratio of the engine.
One of the cool things about the Pontiac V8 is that there are no “big” (or “small” blocks). The 326 and the 455 look the same – are physically the same size on the outside. You tell them apart by casting numbers (and measuring their insides).
There were, however, two basic “lines” – the 326/350/400 V8s (which were shorter stroke designs) and the 428/455 (which were longer stroke designs). Still, most parts freely interchange. You can bolt a 455’s intake manifold onto a 326, for example. And the 455’s heads will bolt right onto the 326.
The 301 was an oddball. It was designed to be very light and the block/heads/intake and other components are specific to that engine. POntiac began to work on it as a potential performance engine (1980-’81) when a turbocharger was fitted (in Trans-Am applications) but then GM killed Pontiac’s V8 engine program and that was that.
Do the heads! Look at it this way- save the stock castings and they won’t wear out/crack like they could in service. If you want it to look stock, paint the aluminum heads. Nobody’s going to look that close anyway. And losing 100 lbs off the front wheels won’t bother you much either.
I agree; paint ’em and casually look the other way. On the other hand, if you just leave them on you don’t have to worry about losing them, says the guy who wants a ’68 Camaro that says 327 on the fender with a small block 400 under the hood!
The 400 would be The Last engine I’d want. They were limited in ways no other SBC was. Push em hard as in revving, and you’d have a place you could store your boot in the side of the block. Stock exhaust manifolds cracked, every one that had much time/work. Take that block and use a stroker crank with corresponding machine work so it would clear and with correspondingly good rods and you have a winner. Or take that block and use a destroked crank via 383, another winner and revving fool. I never saw a single 400 that reliably made power anywhere in the range of a warmed up 327. Maybe I just led a sheltered life.
Have to agree Eight ,the 383 is very popular around here ,The 400 is alright but the engineers werent exactly designing it for HiPo,it comes down to what you are trying to pull with that mill and the level of performance desired , I have a friend who had a Ford He wanted to use for pulling it had a 429 in it ,did nothing else to it but put a big cam in and Had me go Mathias’s speed shop and get him some Blue and the other racing fuel ,the poor old low compression 429 wouldnt hardly even light the stuff.Needless to say He had a miserable performance when Hooked to “sitting Bull “He Basically wasted his money ,he could have very simply made a contender out of this truck by doing a good tuneup ,lower gearsets and lightening it up enough to pull in a lighter class with the proper tires for the average track condition. When I used to attend truck and tractor pulls ,I never saw (even once ) somebody with a notebook taking notes .Back in the day one of the better pullers was a lightly modified 350 Chevy in a good chassis ,for some reason it would just hunker down a pull ,finall y these days these guys have so much money in the ‘strokes and Duramaxs the little Guy doesnt stand a chance .