Good news for Chevrolet Silverado and GMC Sierra half-ton buyers looking for improved performance when towing trailers with GM's new 6.2-liter V-8: A new 3.73 rear axle option is available.
"The first GM full-size pickups with 6.2-liter V-8 engines and 3.73 rear axles started shipping from the factory in late January," said GM full-size truck spokesperson Kelly Wysocki. "They should start arriving at dealers very soon. The 3.73 can be ordered as part of the Max Trailering Package option."
The 6.2-liter V-8 is only available for crew cab Silverado and Sierra light-duty pickups. It's rated at 403 horsepower and 417 pounds-feet of torque and is paired with a six-speed automatic transmission.
The 3.73 rear axle supplements the standard 3.42 rear axle that was previously the only ring-and-pinion set available. It shifts the truck's balance from optimal fuel economy to optimal performance. Still, we expect either version to be among the best-performing light-duty trucks on the road, as we found out during our 2008 Light-Duty Shootout when we tested the 3.42 equipped model.
Rear axles are rated with a number to describe how many rotations the driveshaft must make to turn the rear axle (and rear wheels) once. The rear axle ratio can make a big difference in towing performance. The higher the ratio, the faster the driveshaft turns and the sooner the driveshaft can transfer peak horsepower and torque from the engine to the rear wheels. The result, generally, is faster acceleration and higher towing capacity than a rear axle with a lower ratio. However, if the engine is working harder, fuel economy may fall.
The maximum towing ratings for 6.2-liter V-8 Silverado and Sierra crew cab 4x4s with 3.73 rear axles rises to 10,400 pounds, up from 9,300 pounds in the 3.42 version. Two-wheel-drive crew cabs jump to 10,600 pounds from 9,600 pounds.
The highest tow rating for the Silverado and Sierra remains the extended cab 6.0-liter V-8 pickup with a 3.73 rear axle. Two-wheel-drive versions tow 10,700 pounds, and four-wheel-drive trucks manage 10,400 pounds.