There is no such thing
I think the numbers on the door jam is how much the suspension can actually withstand.So if you throw 2 300 pound fat chicks in the car you are close to exceeding the wieght limit.Than add what ever fuel is in the car and than you will be exceeding the limit.The car comes in roughly around 4k lbs.Most of them wieght at the track are inbetween 3900-4000 which is how I cam up with that number.Mustang are about 500 lbs lighter.