Now wait a second. Certainly a banked road will allow even a crappy car to take a lot of g, but only part of this is truly lateral. For example, you could take a car around a 60 degree bank at a speed sufficient to generate a centripetal acceleration of 3 g, but only 1.5 g would be in the lateral direction (parallel to the pavement). The rest is directed into the track. Meanwhile, good ol' gravity is trying to slide the car down the bank at .866 g. Therefore the net tendency to slide the car laterally is only 1.5g -.866g = .634g. If we're trying to see how the engine handles side loading, these distinctions are quite relevent.