So how does the Sierra Denali perform? Like that most poetic of pugilists the refined and forceful L92 6L80E AWD combo floats like a butterfly and stings like a bee. On the drag strip the Sierra Denali consistently ran 14.8-second quarter mile times at 93.9 miles per hour during three runs at Old Bridge Township Park Raceway in New Jersey. 0 to 60 times were clocked at 6.3 seconds. The truck weighed in at a hefty 5706 pounds, unloaded except for the driver. Although the 6L80E offers operators a manual tap-shift capability for its six speed, I left it full auto for all the runs.
Now, let’s give these figures some perspective through a virtual drag contest against the Toyota. Edmunds.com timed a 2007 Toyota Tundra Double Cab 4x4 with the 5.7-liter iForce with almost identical results. For both trucks the quarter mile and 0 to 60 times are the same, but the Sierra Denali finished .2 miles per hour faster than the 93.7-mph scored by the Tundra. Where it gets interesting is that the Denali is geared for better fuel economy targets while the Tundra is geared for better towing performance.
The Denali’s final drive ratio is a stocky 3.42:1, to help push up its CAFE scores, but the 6L80E’s broad range compensates by using an extremely low 4.03 first gear and VVT to ensure quick starts off the line. The tested Tundra had a much lower 4.1 rear axle ratio, as it was optionally equipped with a trailering package to tow a hefty 10,400-lbs - 1,700-lbs more than the Denali - and it used a 3.33 first gear for launch. One final consideration, the Denali ran the track shod with 20-inch chromed dubs while the Edmunds Tundra used 18-inch wheels.
Another point of relative performance comparison. The Sierra Denali handily beats times posted by stock 2004 Chevrolet Silverado SS extended cab AWD pickups, which typically hit 15.1-second quarter mile times with its 6.0-liter Vortec V8.
The optimal way to launch a Sierra Denali in the quarter mile is to use power braking. With its 4-wheel discs and all wheel drive, the only thing that moved on the truck as the lights on the “Christmas Tree” dropped from red to yellow was its hood as engine torque raised the Denali’s chromed mesh snout. Then the greenlight hit. From there it was a very smooth, very controlled punch through the atmosphere to the finish as the truck shifted through its gears, the engine revved, and the exhaust sang its deep notes. Towards the end, the only thing holding the Denali back was the final drive ratio. A 3.73 rear axle probably would have lowered quarter mile times into the mid-fourteens.