The way I figure it, the coupe with 75 lbs of stereo shit in the car on top of their extra body weight evens us out. I'm not that heavy of a guy so my car could easily weigh less than a coupe with a bunch of junk in the trunk. The factory weight maybe 100 lbs difference, but the street weight is way different. Maybe your wheels are heavier than mine and maybe my stereo is heavier than yours. Factory specs make no difference once you start modifying the car. Don't roll up on a 4 door GSR and figure that he weighs more than you so you will be quicker just because at one point they weighed the same. Maybe he took out his spare tire and has lighter wheels on top of the fact that he weighs 50 lbs less than you do. Now who is heavier?