Originally Posted by mastek
Power to weight is one thing - carrying speed through corners can only be accomplished through LESS weight.
So a lighter car with the same power-to-weight ratio will get a better lap time then a heavier car with the same power-to-weight ratio.
This is only true up to a certain speed. If a track has long straights it might all be negated. Case in point, the Lotus Elise. On long straights it can not over come its aero inefficiency and will set higher times on certain tracks against its comparable pwr/wght competitive set.