Cross-weight
Cross-weight is the share of a car's weight on one diagonal pair of tires, with about 50 percent the usual target for road courses.
Also called: diagonal weight, wedge
Take the corner weights of the left front and right rear, add them, and divide by the car's total weight. That is the cross-weight percentage. If it is 50 percent, each diagonal carries the same load, and the car should turn left and right with the same balance.
Oval racers deliberately run more or less than 50 percent, sometimes called wedge, because they only turn one way. Road and track cars turn both ways, so most setups aim for 50 percent with the driver aboard. A car well off that figure can understeer in one direction and oversteer in the other, which makes it hard to trust.
Cross-weight is adjusted with coilover spring perches, not by adding ballast. Small height changes at one corner make big cross-weight changes, so work in small steps and recheck ride height and alignment afterward.
A cross-weight near 50 percent gives symmetric handling, so what you learn in left-handers also holds true in right-handers.