Weight plays a crucial role in every aspect of your car. Not only performance but also wear and tear on parts. Not only will it allow you to accelerate better but, with it taken out of certain places will help your car handle better, brake better, launch better. How much you take out is a personel opinion and what you want to live with, but there is no point in going to the track with a full tank of gas, spare tire, jack, and simple things to give you that little extra time. it could be the difference between a 13 sec pass and a high 12.