Toyota's approach to improving ICE efficiency

[cRiPpLe_rOoStEr]

Originally Posted by Ecky

Probably best to look at torque after the transmission. Two 200HP motors, one with twice the torque at the crank and the other with twice the RPM, both have the same output after gearing.

Sure. And that explains why some older and apparently oversized engines may eventually get better mileage and more reliability than some downsized high-revving ones.

[sendler]

Except that the modern engines use new techniques for efficieny such as Atkinson and high egr. Or ulta high effective compression ratio with turbos and direct injection along with minimized surface area to lose less heat energy via smaller displacement.

[cRiPpLe_rOoStEr]

Originally Posted by sendler

Except that the modern engines use new techniques for efficieny such as Atkinson and high egr. Or ulta high effective compression ratio with turbos and direct injection along with minimized surface area to lose less heat energy via smaller displacement.

Who says it's impossible to add such tech to a lower-revving high-displacement engine in order to further increase both efficiency and long-term reliability?

[sendler]

Larger displacement makes for more surface area in the combustion chamber to pick up heat which is wasted energy.

[cRiPpLe_rOoStEr]

Originally Posted by sendler

Larger displacement makes for more surface area in the combustion chamber to pick up heat which is wasted energy.

It depends. The larger-displacement engine could eventually have a more undersquare profile, eventually with the same bore of the smaller engine.

[sendler]

Agreed. Undersquare is a key to heat efficiency in piston engines.

[slowmover]

Originally Posted by easythereturbo

I would argue that modern base-engine sedans *are* powerful as well as affordable. 0-60 in under 8 seconds used be considered quick. Fact, its just as quick as it ever was, its just that people are power drunk these days.

X2

Cars were plenty "fast" in the 1960s before weight and emissions ruined a good pairing. Good relative highway fuel mileage as well.

Load the sedan to maximum capacity.

Or hook up a trailer that represents the same.

In each case 0-60 in 20-seconds has always been considered good. 30" is just at acceptable.

Steady state economy should factor. Along with running air-conditioning, power accessories and the rest. What only a really big cubic inch engine in a luxury car could do.

More than this is kinda stupid.

Everyone likes to cruise effortlessly. And great mpg with a great ride.