Why do american cars have such big engines, but produce so little power?

Question

The Hemi is 435bhp and 5.7 litres
The BMW M5 engine is 5 litres and produces 507 bhp.
TVR manage to get 405bhp out of a 4 litre V8.

In comparison American engines produce less power per litre.

Answer 1

its not a problem with the usa engines its the large skip attached to it

Answer 2

The fact is that it takes complex and expensive parts to produce an engine that makes a lot of power per liter.

The Honda S2000 produces 120 horses per liter, but requires race grade materials in the engine to do so. Mileage isn't great considering the car only weighs 2750 lbs, and the engine is very expensive to replace. European countries prefer smaller engines also, because they are taxed on larger engines.

American car companies found that the cheapest way to make big power is by making a big engine, even if the hp per liter isn't high. Nothing wrong with that. You don't have to pay for high strength materials, or variable intake systems, and mileage is fine if the whole car doesn't get too weighed down (Corvette). The US also has a massive abundance of cheap iron which helps.

Answer 3

Historicaly that was true but it's not really true any more. For instance a Honda Accord has a 2.2 litre 4 cyl engine and it makes 150 HP. Thats 68 HP per litre. The Ford Mustang has a 4.6 Litre engine and it makes 300 HP. Thats 65.2 HP per Litre. Not much difference there. The Corvette Z06 makes 400Hp with 5.7 litres. Thats 70 HP per litre.

Answer 4

I think you will find its down to the capability of large engines to do huge mileages. Cars over there tend to be designed around the fact that America is a bloody big place and you tend to have to drive further to get anywhere. Engines over here only usually last 150-200,000 miles whereas over there, they should double that. Another example is truck engines.....the smaller trucks with huge multi litre engines don't tend to be much more powerfull than the diesel engines in big cars, but they are capable of several hundred thousand miles. Its just the gearing and torque that help pull the extra weight,

Answer 5

i love replacing equipment and transferring between second and third on united states of america lanes. pass watch some eu rally utilizing. also reliable to have a reliable rev variety at the same time as utilizing for the time of europe as we've intense % limits, and on lots of the autobahn has NO % reduce. thats why many euro vehicles can fortuitously cruise all day lengthy at one hundred sixty-180mph. even my previous nissan micra took the regensburg highway at 110mph and that turned right into a a million litre engine.

Answer 6

Because fuel is cheap over there, so, with typical American mentality, they think that bigger is better......after all this time, they still havent mastered the art of making a decent car....you can count on one hand all the truly beautiful American carts (Ford GT & GT40).....and as for them sounding good....watch Clarksons "Good, Bad & Ugly" DVD....he has a sound comparison of an American V8 & then a European V8......NOW tell me that American cars sound good!!

Answer 7

Because they run on baked beans. The normal "gas" in the US is 88 octane as opposed to 91 for unleaded in the UK, so you need a 3 litre to get 2 litre performance. They're getting better though. Ford Taurus (Granada size) is pretty nippy.

Answer 8

They haven't yet discovered how to make a car turn a corner properly.

American's can't design cars properly, they all look like wardrobes on wheels, except the Ford GT.

Big cars, big engines = small willy

Answer 9

They also handle like a wet bucket of sh1t. America is all about the biggest, not the best. Quantity over quality everytime.

They do make a lot of noise though - but so does a tractor, which probably goes faster too

Answer 10

yes the 435 hp hemi and 500 hp vet are real slugs.