gas mileage?

Question

so i see that one of the only arguements that rice burns use against muscle cars is that they get awesome MPG. well this is true if both cars are stock but if, say a civic, is pushing 500+HP with turbos and all the stuff on it, does it really get much more MPG than a muscle car?

Answer 1

Yes. The small car should be better, because that power doesn't have to work as hard, since the car is much lighter, and probably more aerodynamic. Aerodynamics can make an enormous difference, especially at high speeds.

Now for some physics. A given amount of fuel makes a given amount of power, and it takes a set amount of power to accelerate a given mass at a given rate.

In a perfect world, assuming 500 hp in each car, to accelerate at the same speed, the smaller car would need less power, and so use less fuel. If they both used full power, fuel consumption would be about the same, except that the smaller car would be ahead, and would therefore be able to get off the gas at the end of the trip, while the heavier car is still hard on the gas. This is why race cars are built as light as they can - more speed and better mileage (which means less stops for fuel.)

The biggest difference (in the real world) would be how much fuel each car wastes. High performance cars always throw a lot of unburnt fuel out the exhaust pipes - the extra fuel in the cylinders helps keep the piston cool, to avoid melting. Also, the more power you get per cc of engine, the more inefficient it will be when it is not in the power band. This means that the smaller engine is technically less efficient (although turbos help to eliminate this problem, as they need very little valve overlap - which is what creates this inefficiency), although it would probably still use less fuel than the large vehicle. variable valve timing (like Honda's V-Tec system also help avoid this inefficiency, as it effectively has two power bands - a bit like being able to change the cam while you're driving.

Also, smaller vehicles don't just have less weight - they also have less inertia (meaning that they are easier to get moving from a stop) and less momentum (meaning that they are easier to stop and turn.) So, in the real world, they also wouldn't have to slow down as much to turn a corner, giving them a speed advantage as they exit the corner. This means that they don't have to accelerate as much to get back up to cruising speed as the heavier car.

Answer 2

a tricked out civic would probably still get better gas mileage than a tricked out muscle car.

Answer 3

It probably will.. and .. it will run longer without needing parts.