- gm's full-size suvs—including the chevy tahoe and suburban, gmc yukon, and cadillac escalade—have intrusive electronic stability control.
- we've had to engage low range on the four-wheel-drive suvs to disable the stability control system during our skidpad test. using that method, the best result we've recorded is a lackluster 0.73 g in a gmc yukon denali.
- the diesel tahoe's top speed is limited to 35 mph in 4low, which led to a pathetic 0.53 g result and the first time a vehicle's skidpad performance has ever been limited by its top speed.
general motors' new large suvs are limited by their intrusive stability control systems in our cornering test. our skidpad test takes place around a 300-foot-diameter circle where we measure average lateral grip while turning both left and right. we test hundreds of vehicles every year, and the results are typically influenced by factors such as tires and the vehicle's weight, and variants of a given model usually perform similarly. but these new body-on-frame suvs were a bit different.
the anomaly first cropped up during our first test of a 2021 chevrolet tahoe z71 equipped with a 5.3-liter v-8 and goodyear wrangler trailrunner all-terrain tires. the stability control system is so invasive that we had to shift into 4low to disable it before we could achieve maximum skidpad performance. in two-wheel-drive mode, the system severely cuts power when cornering near the vehicle's limits. even when testing the new tahoes on the public roads we use to determine our annual 10best awards, we noticed stability control butting in. we've tested six variants of gm's new large suvs, and the best result we've recorded is an unimpressive 0.73 g from a gmc yukon denali. for reference, the highest number we've recorded to date is 1.24 g in the 2019 porsche 911 gt3 rs, and even heavy-duty pickups can corner in the 0.70-g range. a result below 0.50 g is unheard of for a contemporary passenger car.
things got even weirder in a tahoe with the available 3.0-liter diesel engine. as before, we shifted it into 4low, but this time test driver k.c. colwell reported that despite requesting additional upshifts, no more speed was arriving. he was in 10th gear and up against a 35-mph speed limiter that comes into play in diesel variants when in low range. that equates to a maximum cornering figure of 0.53 g, a whopping 27 percent less than the best cornering ability we recorded in the gas-powered version. when we inquired, a chevrolet spokesperson did not offer an explanation as to why the diesel is limited to a lower speed in 4low than its v-8 brethren.
while our skidpad test is not something drivers will replicate on the road, it tells a lot about the performance capabilities of these three-row suvs. when asked why the system is so aggressive, chevy said only that the goal was to "ensure safe vehicle operation for a wide range of driving conditions and driver inputs." we suspect that the system is limiting the truck's lateral capabilities as a workaround for an engine-oiling weakness, because trailing closely behind every escalade, tahoe, suburban, and yukon on the skidpad is a james bond–grade cloud of oil smoke.