[nativepaul]

I don't think its quite that straightforward either but I think that was a bad example, drag increases with speed on a cube root basis, so any given car, boat or plane will need 8 times the power to do double the speed, with a veyron engine in your dads astra it would go 200MPH, the fact that the veyron goes 250MPH shows that Verons are more aerodynamic than old astras. Weight makes a negligible difference to either drag or top speed except that a heavy car will accelerate slower and thus may no longer have room to accelerate up to top speed on a given straight, given room it will lumber up to the same top speed.

Acceleration is fairly constant for a given power to weight assuming you can get decent traction and our top speed is gearing limited not power limited so it should be close to 25% less current for the same voltage if you are racing on a short track which is mostly acceleration with a very short amount of time at top speed, the longer the straights the less difference in current you will see, and likewise if your bashing the type of bashing you do will make a big difference sometimes I'm doing small ovals in the road outside which would be near 25% and sometimes I'm just buzzing round the park and the bigger wheels and ground clearance of the truggy would be less drag in the grass and the truggy would have the advantage.