I can't believe no one else posted this, but the vette only has 5! That's why vettes are lighter, less studs, lightweight wheels, larger cargo area. Less structure, smaller car, lighter duty components, smaller tires, etc. People buy them because they have cup-holders??? Lol.
Stronger is better, especially for a race designed car. You live longer with 6.
And when I head-on'd a Semi I'm still alive because I was in a Viper.
Ted