LET ME STOP YOU RIGHT THERE

Any braking test is a measure of how quickly the entire braking system gets up to peak performance and stays there throughout the stop. A vehicle with a strong system should stop from 100 mph in about double the distance it does from 70. But a number of factors affect the results. For example, a vehicle with aerodynamic lift will have less traction available early in a stop, whereas a vehicle with downforce will benefit from plenty of initial bite. As in all braking tests, tire traction is a major contributor to how quickly a vehicle can slow down. In 100-mph testing, particularly with vehicles wearing allseason tires, we occasionally notice grip falling off before any brake-pedal softness. And then there’s how well the brakes shed heat. Stopping a 6781-pound Ram 1500 TRX from 100 mph causes enough brake fade to more than double its stopping distance from 70 mph. Fade affects more than just big pickups—the brakes on the Acura TLX Type S and the Cadillac CT5-V also wilt from triple-digit speeds. We’ve just recently begun to compile 100-to-zero data, and for now, Porsche sits atop that leaderboard with the 718 Cayman GT4 RS, which took only 242 feet (with an average of 1.38 g’s), against

132 feet from 70 mph (1.24 g’s).