Unless you live in Germany you're not really ever going to hit that top speed. You will however have ample chance to take advantage of the acceleration.
By and large it is more efficient to accelerate at full power, assuming your goal is to reach a certain top speed regardless, so if you were _really_ concerned about conserving petrol then you should be going full blast off the line. That said I expect the fuel usage such a situation to be negligible anyway, especially to someone who can afford/justify a car that does it in 4 seconds.
My car isn't that fast, or particularly economical, but I know I've never thought "I'd love to accelerate at full power here to show how fast my car is, but I just can't justify the pennies it will cost me"! Outside of hyper-milers I wonder how many people do actually think about it.