I have been researching door tags on Camaros, Firebirds, Corvettes, GTOs and Mustangs. It seems that GM, with the exception of the GTO, weighs each car after it is built and uses this number for the GVWR. I say this because they are all a little different, even if the cars apear to be identicle.

I will use a 2001 Camaro as an example. They all have a payload of 701lbs. One car has a GVWR of 4244 and another identcle car has a GVWR of 4225. When you subtract 701lbs you are left with 3543 and 3524lbs. This should be the curb weight.

Corvette and Firebird work the same way. GTO does not. All GTOs show 4465 or 4491. Options do not matter.

One thing is consistant though, the front and rear weights for GM will add up exactly to the total GVWR. This is not true for Ford.

Also, when you subtract the payload from the GVWR you are left with a much larger number than what the curb weight should be.

Ex 2006 Mustang GT GVWR4450 F2170 R2340 Payload 720. 2170+2340=4510. 4450-720=3730.

I know what each weight is but I don't understand why some numbers do not calcuate correctly or why identicle cars can have slightly different weights.

GVWR-Gross Vehicle Weight Rating-The weight of the car full of fuel plus maximum payload.

Curb Weight-The weight of the car with standard options full of fuel with no passengers or cargo.

Payload-the maximum weight that can be added to the car including passengers.

Curb weight and payload should equal the GVWR.