The rate of acceleration is indicated by the slope of each line -- the flatter the line, the greater the rate. That doesn't sound right to me... more, please. ... and it is a fact the rate of acceleration, in all gears, will be less with a 3.62 diff. That may be true overall, but it isn't at all points. Imagine, for example positive flat-out acceleration at a road speed where you have just had to change up in the lower geared car because of the rev limit or being over the top of the power curve. In the higher geared car where you hadn't yet had to change up you'd be at higher engine speed with more excess power and greater acceleration. Jonathan