Quote:
Originally posted by russotto
The problem with using hp/l as a measure of performance is it indicates that increasing the displacement of an engine somehow reduces its performance. It gives the impression, for example, that a 1.0l engine which develops 75hp is higher performance than a 2.0l engine which develops 130hp -- even if the engines are the same weight and approximately the same size.
|
But they are not the same weight or size. Increasing displacement also does not decrease performance. A 2 liter engine gets 140 Hp. An equivalent 5 liter engine gets 350 Hp. They have the same performance. A standard performance 3.5 liter V-6 engine gets about 240 Hp. To get 240 Hp from an obsolete technology (low performance) engine, that would be a 4.7 liter V-8 in the Jeep Grand Cherokee. To get the same horsepower, the low performance engine adss more pistons, valves, block, head, fuel injectors, etc. IOW lower performance results in a larger engine and a vehicle that costs more to build.
Guess what. GM low performance engined cars cost more to build than equally equipped Mercedes Benz - because GM uses lesser technology, lower performance. This is further confirmed by a well know industry fact - GM earns no profits on their automobiles - using SUVs to cover up auto losses.
Whether it is a 1.8 liter 135 Hp engine or a 5.7 liter. Both will have the same performance if designed and machined to the same technologies. Based upon the 1.8 liter performance, then how many horse should the 5.7 produce? 425 Hp. The Corvette only does 385 Hp because it does not have the same performance - the Corvette it is a lesser designed engine hyped to the ignorant as a high performance automobile.