Quote:
Originally Posted by ERTW
Late intake valve closing does wonders for efficiency - the toyota 2.5L is 37% thermally efficient - and gives the turbo lag feel. It seems that a large engine with the performance of a small one may be better than a small engine with the performance of a larger engine. Fwiw downsizing more than 30% hurts transient response, and turbo engines aren't as fuel efficient as they're marketed.
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My mom has a 2003 Acura TL with a 3.2L V6 VTEC engine and it uses less gas than my RDX with a 2.3L Atkinson cycle turbocharged engine with all the latest honda gizmos like variable valve lift and timing (intake & exhaust). Of course the turbo car is a 500lbs heavier suv with 4WD and tighter gear ratios, so it's not a fair comparison. But look at the jetta hybrid with 1.4L turbo gas that gets you 42mpg city and 48mpg highway. pretty impressive for +180ft-lbs of torque. It does better than the TDI (turbo diesel) models which is epa rated at 42 highway and 30 city.