Originally Posted by TIFF-C20WTH
TOTALLY depends what you want out of the car
.55 will be punchy
.63 will be strong at high speed
Both are good though
My experience has been
.48 = punchy
.63 = strong top end
.55 = wooly middle ground
There IS a difference, but its not really a massive difference, i bet your average (not mega familiar with cossies) enthusiast could drive a car with a .55 one day and a .63 the next and not really notice the difference.