8 September 2005
Changing the laws of physics
Mr Scott, of course, would tell you you canna do that, Captain, but nowhere does it say in the manual that you can't avoid facing them head on.
Your serious drivers eschew front-wheel drive: with two-thirds or so of their weight up front, fwd cars understeer at the limit and often well short of the limit, and sending your power through the same wheels you steer means that sooner or later you're going to put your foot in it and head off into the weeds. This latter phenomenon is called torque steer, and the only reason I don't often experience it in my fwd car is because it doesn't have enough power to force the issue. (Believe me, I've tried.)
Building a fwd performance sedan, therefore, requires some serious rethinking of those laws. The brain trust at Pontiac thought it over, and reasoned: "If we want to improve traction on a rear-driver, we'd put bigger tires on the back. What if ...."
And apparently no one thought of this before. The new Grand Prix GXP has fat 225/50-18 tires in back and fatter 255/45-18 tires in front. Wouldn't this bigger contact patch make torque steer worse? Apparently the controlling factor is the stiffness of the sidewall. (Tire pressures are the same 30 psi front and rear.)
Car and Driver has a full road test in the October issue. Between this and the new Solstice roadster, the We Build Excitement guys might actually be building some excitement these days.Posted at 7:59 PM to Driver's Seat