Mick, Not sure exactly what your question is addressing but I'll take a few different viewpoints for you. A car that accelerates evenly would have a graph represented by a straight line. The y axis would be speed, the x axis time. A car that accelerates harder and harder would have a logarithmic curve - like the bottom right quadrant of a circle. A car that starts off accelerating hard and then the acceleration drops off would have a curve like the top left quadrant of a circle. At all times the car is accelerating, but at the start it is accelerating far harder than at the end. The other answer you may be after is that if a car is stopping from a constant speed then it is going to have a certain amount of force behind it. If it is at that same speed but still accelerating, it will have more force, and hence require more braking force to stop it. Also, as mentioned earlier, if you are accelerating harder, the amount of distance you cover during your reaction time from taking your foot from the accelerator to the brake is much greater than if you were accelerating slower. One final point - Peter, I know your kits all provide ADR compliance, but it's safe to say that 90% of the kits you have supplied are "illegal modifications" since the owners of those cars have not yet obtained an engineers certificate!