On the pad we compared the Silverado and Tundra by executing three maneuvers to produce front and rear wheel skidding: a sudden brake stop from 30 miles per hour with minor steering input, a sudden brake stop from 30 miles per hour with a single lane change, and a sudden brake stop from 30 miles per hour with a double lane change.
We only tested in 4x2 mode because the Tundra, unlike the Silverado, disables its ESC in 4x4 mode, leaving the driver with only ABS and Active Traction Control (A-TRAC) functions. A-TRAC is different than VSC. A-TRAC works like a virtual limited slip differential (LSD), by applying brake pressure to a slipping wheel to reduce speed differences between left and right drive wheels, causing engine torque to be transmitted to the wheel opposite the slipping wheel to gain traction. This is different from VSC, which, again, works by measuring slip rate against some pre-programmed threshold and can brake multiple wheels simultaneously to regain control and traction.
In each maneuver both trucks clearly benefited from ESC. In fact I can’t imagine wanting to drive a pickup now without traction control because of the enhanced safety it adds. However, the Chevy’s StabiliTrak simply performed better than the Toyota’s VSC. There was much less modulation noise from the Silverado’s ABS system and steering feedback and vehicle behavior was much smoother and predictable throughout the traction control event.
The Tundra’s ESC intervention, in contrast, was coarser. Its brakes were louder and it tended to let the rear slide further before correcting the skid. Also, when the Tundra gave up its grip on the tiles, a warning buzzer went off in the cabin to let you know you’d lost traction. No, really? It’s an unnecessary and distracting feature that draws driver attention away from recovery to focus on where the noise is coming from.
That’s not to say GM’s setup is without fault. I spent some time autocrossing a GMC Sierra 4x4 and during one hard turn I apparently tripped a rollover sensor which triggered an automated call from an OnStar operator to see if I was ok. GM says they’re working to dial back the sensitivity of the truck’s sensors to such maneuvers. It should also be mentioned that Toyota offers VSC standard on all 4x4 Tundras, regardless of cab type, whereas GM only offers StabiliTrak as standard equipment on 4x4 Crew Cab models and as an option for Extended and Regular Cabs.
But after running through skid pad cycles twice in each truck, the simplest way to describe the advantage of GM’s ESC over Toyota’s is that it works with the driver rather than just for the driver.
In closing, I’ll echo Sam Abuelsamid’s comments at the end of his story about this GM sponsored event, because I think he’s in sync with where I’m at. GM’s on a roll with its big pickups. At this moment in time, I think they’re the best all-around light and heavy duty trucks you can buy for the money.
But the good news for fans of other trucks is that this will definitely push those brands to make better rigs. There’s no other choice. In these ultra-competitive times no manufacturer can afford not to make continuous improvements to their current trucks and to their next generation products. All trucks are only going to get better from here.