several reasons probably, no matter how much power and torque you have, your performance in a car a bike or any wheel driven motor is all going to be down to the tyres gripping and putting it on the road, hence, loads of power or loads of torque makes no odds if the tyres you use have a certain limit as to how much they will hold. plus, if the cars had engine management systems, its possible that they might have been detecting wheelspin and limiting power or torque to help traction, thus narrowing the gap between the claimed outputs of both vehicles. lets say that a tyre can cope with 250 hp before it lets go, so two of them can handle 500bhp, 4 of them could put down 1000 bhp if you had 4 wheel drive. but if your engine management detects that the 700bhp you are trying to use is making the tyres lose grip, so you might well only be putting down 500bhp with your boot to the floor. now elevated bhp figures that can overcome grip at heavy footed moments, might only show an advantage over a lower powered car at higher speeds when it has to overcome wind resistance, (oh, yes, aerodynamics might also slow down a car compared to another) and finally, you assume that if a car maker says it makes 500bhp that it actually is, manufacturers have been known to be very sparing with the facts with regards to power and torque, sometimes measuring at the ncrank rather than the wheels, and sometimes telling porkies.
so if 2 cars have similar wind resistance and weight but have the same performance over a standing quarter or half mile, then perhaps the performance difference might only become apparent at higher speeds.
oh, and clarkson is a dick, i woldnt accept anything he said on tv as being related to reality in any way.
