Today's new cars are way overpowered...

[SPYDERLK]

Weight is a low factor in highway driving, but a high factor in city driving. Aerodynamic drag: vice versa.

 

[corl]

Manufactures are going to smaller turbocharged and supercharged engines to get more power from smaller displacement hence lighter engines and the turbo helps with the emissions. Remember when you could get a HP from a cubic inch of engine displacement (350 cu in-350 hp). Now you get that in a cubic centimeter.

 

[Jstpssng]

Manufactures are going to smaller turbocharged and supercharged engines to get more power from smaller displacement hence lighter engines and the turbo helps with the emissions. Remember when you could get a HP from a cubic inch of engine displacement (350 cu in-350 hp). Now you get that in a cubic centimeter.

And they can deliver better mpg's. A new F150 with a little 3.5 dual(?) turbo can give low 20's and I've been told is quite peppy.

 

[George2615]

I'm happy with my 2012 way overpowered 400+ HP 6.2L Camaro. Lots of power and still gets 22 MPG around town and 26 MPG highway if I keep my foot out of it. Camaro requires premium fuel of which I use non-ethanol.
Not so happy with the truck. Silverado 5.3L only gets 16 MPG around town and maybe 19 highway. Maybe I should try non E premium in the truck or look for a 6.2L to drop into the truck.

 

[AGRIMAN]

But there are times when there's no replacement for displacements. Cubic inches = cubic dollars

 

[strum456]

If the power is there then people tend to use it.

It is the rule rather than the exception that people hit the gas hard, then shortly there after slam on the brakes becasue there is nowhere to go. When pushed to its limits, a more powerful vehicle will do more work in less time and therefore uses more fuel. Turbos increase and engine's volumetric efficiency, which essentially means that more fuel and air can be burned by a smaller displacent engine, IF YOU TELL IT TO.

Keep your foot out of the firewall (and I mean both pedals)!

 

[turnkey4099]

The auto manufacturers are building what the customer wants & is willing to pay for. One of my neighbors bought a new Dodge "something" for his 19 year old son. He was telling me how fast it was and that it had more than 400 hp. I was silently thinking - fortunately the neighbor is still in his "reproductive years" because when his wild a**ed son zooms off the road and kills himself - he will be able to father another child.

Yep, and the SUV is a perfect example. Not really suited to any of the jobs it is used for except in very few cases. Soccer mom driving kids to a 'doings' would be better served with a minivan.

Harry K

 

[Bird]

Remember when you could get a HP from a cubic inch of engine displacement (350 cu in-350 hp).

I'm old enough to remember when that was a "goal" rarely attained. I bought one of the first (1968) Plymouth Road Runners; 383 cu. in. and 335 hp. It could do 130 mph, but in normal highway driving, on a good day I could get as much as 13 mpg.:laughing:

 

[gladehound]

I don't see much difference in efficiency of performance cars in the last two decades:

My 2012 mustang would get 23mpg at 80 mph and 26 mpg at 60 mph on the highway. Not bad for a 400+ hp v8 powered 3600 pound car.
My 1993 Lincoln Mark VIII would get 27 mpg at 80 mph, 280 hp v8. 3700 pounds but very aero. Much better highway mpg than mustang and much older tech.

My old economy cars were every bit as good as todays.

My 1988 Ford Escort would get 40 to 44 mpg on the highway no matter how you drove it. 115hp I4. A bit over 2000 pounds.
My 1980's dodge cult would get 40-45 mpg on the highway or around town. ~60 hp I4, 1600 pounds and 8 forward speeds.

But what you can get today that you couldn't get a few decades ago is a nice roomy sedan that gets 30 mpg. I rented a lard ford sedan with a small ecoboost engine in Colorado and averaged 28.5 mph in ~700 miles ranging from 6,000 to 11,000 feet in elevation. It blew my mind! A car with that much interior room from the 70's would have gotten 8 mpg under the same conditions and wouldn't have been any peppier.

The small turbo engines use less fuel at idle and low power situations than large naturally aspirated engines of the same max power. The small turbo engines actually tend to make better low end torque as well. If you can keep your foot out of it and get a small turbo engine in a large aero car, that's about the best thing going today.

 

[2LaneCruzer]

Quick check - 1983 Accord, weight about 2100 lbs, 75 hp engine, small sedan with low roof height.

2014 Mazda CX-5, weight about 3200 lbs, 155 hp engine, boxy, somewhat tall SUV.

Getting close to the same gas mileage would be a minor miracle.

Can't argue with that. I'm amazed, however, that the Mazda gets in the high 30's burning the high octane, non ethanol gasoline...and it runs like a scalded cat if you punch it.