The method of locating the longitudinal center of gravity is easy if you know the weights bearing on the front wheels, and the weights bearing on the rear wheels. The LCG is found by a mensuration of “moments” – the products of weights and distances from a common point.
A workable common point could be 1” ahead the front axle (you can’t use the front axle itself because a real distance must be involved). The smart’s wheelbase is 73.5”, so the front axle is 1" behind the common point, while the rear is 74.5" behind. The curb weight of a smart coupe is 1808 lbs.
Just for argument, let us say that the smart has a 45/55 front-to-rear weight distribution, thus there is 813.6 lbs on the front and 994.4 lbs on the rear. Proceed thusly:
Front moment = 813.6# x 1” = 813.6
Rear moment = 994.4# x 74.5” = 74,082.8
Add the moments – 813.6 + 74,082.8 = 74,896.4
Divide that sum by the total curb weight – 74,896.4/1808# = 41.425
The LCG is located at 41.425” behind the common point, or, 40.425” behind the front axle.
I finally did a Center of Balance. Now last time I weighed my car it chimed in at 80 pounds less! This time the gross weight is 1840. Now my front axle weight was 760 and the rear axle weight was 1080.
I'm weird that way. I teach a class about once or twice a week where I have to explain the CB formula. 
That explains my enthusiasm.
Linear Mode
