Last year at the KO Propo race, the minimum weight was 1525 grams. This year at the Reedy Race the minimum for 6 cell was 1525 grams, and 1450 for 5 cell. I try to keep my car at 1525 minimun and work with that. Reedy race cars with 5 cell didn't seem to have the same zip as 6 cell cars but were putting in the same lap times. I would guess having less weight to carry makes the car take turns easier.