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I'm impressed by the fact that we have factory 400-700HP V8's that can idle smooth as a low-HP 4cyl, have excellent drivability, and get better gas mileage than V6's from a decade ago.
20 years ago, to get 700HP out of a v8 required extensive mods that resulted in poor drivability and reliability.
Contender for worst idle is the 4 cylinder "range extender" (ha... ha) in the Chevy Volt. When it kicks on in "high idle" to regen the traction battery, describing it as a cacophonous snarl is an understatement.
Funny about the V6's their whole motto was "the power of a V8 with the economy of a 4-cyl" when it's been the opposite... LOL
You are right but on all counts. The closest car to what you are describing is the GEO Metro in 1991 at a weight of 1620 lbs.
The MPG was 43/51 with a combined MPG of 46 mpg.
The closest car to that description today is the Mitsubishi Mirage weight 1973 lbs 41 MPG highway
So has the 353 lb weight difference between these two vehicles cost 20% in fuel economy, 30 years later with all the mentioned innovations on this thread?
Has anyone found that internal combustion engine efficiency data 40 year time line yet. Thank you for your responses.
To be fair, you need to compare the Mirage to a 4 door Geo Metro hatchback which averaged 33 mpg with the automatic transmission. The Geo's hp to weight ratio was .032 vs the 4 door hatch automatic Mirage's .04, and averages 39 mpg.
The Mirage is much quicker, much safer, much more comfortable and gets avg 6 mpg better even though it weighs about 300 more lbs.
Another part of the equation is that people simply didn't drive as fast in the past.
Quote:
Originally Posted by EckyX
This is true, broadly speaking. Aerodynamic drag goes up with the cube of speed, making it hard to get good fuel economy when driving faster. Another part of the equation is that people simply didn't drive as fast in the past.
I get around 65mpg at 75mph in my Insight, but it's also a tiny, 2-seater, rattly, slow car with no creature comforts and the bare minimum in features.
Look up Montana's or Nevada's speed limit before 1970 there was none. Back to the question of engine efficiency. Could corn in the gas be a factor? How about catalytic converters and back pressure. Both of those variables are counter to engine efficiency and added within the question's 40 year timeline. I'm still looking for the data on the original question.
Exactly right. Law of Diminishing Returns. They took the $200 carburetor away and replaced it with a $2000 injector in order to gain 10% in fuel efficiency.
They only every-day-practical advantage of new, computer controlled engines over the old points & condenser ignition, flushing toilet carbureted cars of 60 yrs ago is that the new one are easier to start in cold weather. Only the super cars of that era could go 120mph. Now any run of the mill commuter car uses 4 valve, gear driven double OHC and over square pistons to achieve better power efficiency.
The vast majority of improved fuel efficiency achieved in the last 50 yrs has been because cars are now smaller and lighter. E = 1/2mv^2..... V has only increased a little. M has dropped a lot.
Remember the Geo? It got 50mpg, but the EPA and lawyers took it away from us. Now they're trying to shove EVs & self-driving cars up our a...er...down our throats.
Well. A modern EFI car with solid state ignition does not need to be tuned on a regular basis like a car with points and a carburetor does. But really the great cold starting is just a high-energy ignition system of some sort combined with fuel injection of some sort. My old 82 Scirocco is a great starter when it's cold out, I'd put it up against a new Toyota or whatever. Part of why I keep that old 'roc is that it's a 40 MPG or near that car that is not an out and out econobox. Also it dates from the era when Volkswagen made an effort to make their cars easy to work on, accessible to any competent DIY mechanic.
Look up Montana's or Nevada's speed limit before 1970 there was none. Back to the question of engine efficiency. Could corn in the gas be a factor? How about catalytic converters and back pressure. Both of those variables are counter to engine efficiency and added within the question's 40 year timeline. I'm still looking for the data on the original question.
Yes, it definitely is. If you can find ethanol free gas, try it, you will see a noticeable improvement in MPG. Generally it costs enough more than E10 gas that your actual cost per mile goes up, but I run E-0 gas anyway.
Early catalytic converters had bad flow characteristics - by early I mean 1970's. Modern ones don't impede exhaust flow to any noticeable extent.
Yes, it definitely is. If you can find ethanol free gas, try it, you will see a noticeable improvement in MPG. Generally it costs enough more than E10 gas that your actual cost per mile goes up, but I run E-0 gas anyway.
Early catalytic converters had bad flow characteristics - by early I mean 1970's. Modern ones don't impede exhaust flow to any noticeable extent.
Gas station in my area sells ethanol-free 89 out of a separate nozzle (luckily my vehicle is spec'd for 89, not 93) which is usually priced above premium. The prices of gas, in general, have risen so quickly as of late that they don't dare change it when premium is $3.49/gal.
It's sitting at $3.19 right now, at or below what they're charging for mid-grade with variable traces of ethanol.
Gas station in my area sells ethanol-free 89 out of a separate nozzle (luckily my vehicle is spec'd for 89, not 93) which is usually priced above premium. The prices of gas, in general, have risen so quickly as of late that they don't dare change it when premium is $3.49/gal.
It's sitting at $3.19 right now, at or below what they're charging for mid-grade with variable traces of ethanol.
What I have readily available is 90 octane "mid grade" which I am reasonably certain is what they make the 92 octane E-10 out of, Conoco or 76 stations. We also have Pacific Pride, a card-lock outfit, they have 87 octane E-0, and 92 octane E-0, but you have to set up an account and get a specific credit card through them. The Conoco/76 stations will take most any regular credit card. Typical price for the 90 octane is $1 per gallon more than 87 octane E-10. So, last I looked, $3.29 or $4.29. The old Cougar calls for 87, but it's got a lot of miles, and it will ping more than I want to put up with using 87. The Scirocco, I have turned the spark timing ahead about 5 degrees beyond stock, it would ping using 87 in hot weather. Whatever. 90 is what I can get easily.
Mavrik stations have 87 octane E-0 for a better price, but none are close enough to my usual routes to make it worthwhile.
I should get off my butt, and get a Pacific Pride account set up.
I don't know how easy it is to R&R a fuel injector, in my 25+ years of driving fuel injected vehicles I've never had one go bad - that's part of why I think so highly of the design. Whenever an ancient carb'd vehicle passes by, I can smell the unburned fuel it leaves in it's wake. The difference in efficiency is staggering.
I'm not going to debate something that is so black and white. When FI came out every single vehicle went to it. There was no debating which was the superior design, it was simply a no brainer improvement, a monumental leap in vehicle technology. Go argue with yourself if you want, I'm done.
The Chevy sprint which was originally a Suzuki in the Japanese market was able to get 44/53 miles per gallon via carburetor back in its day 1984. No smell of un-burned fuel behind it.
Fuel Injection was around on the GM stuff in 1957 and before (Pontiac Bonneville) as an example and had it's own bumpy ride before engineers refined and tamed it. 63 years ago
The Chevy sprint which was originally a Suzuki in the Japanese market was able to get 44/53 miles per gallon via carburetor back in its day 1984. No smell of un-burned fuel behind it.
Fuel Injection was around on the GM stuff in 1957 and before (Pontiac Bonneville) as an example and had it's own bumpy ride before engineers refined and tamed it. 63 years ago
And so we move forward.
Carburetors can work great if they're tuned right. It's very possible to get phenomenal economy in a carbureted car. But, go up in elevation, or have a major change in outside temperature (it can swing 120 degrees here) and they suddenly don't do as well until retuned. Plus they can just drift out of tune over time on their own.
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Another part of the equation is that people simply didn't drive as fast in the past.
