To make its 2020 half-ton pickup trucks more appealing, GM will announce improvements to increase tow ratings for its Duramax diesel Chevy Silverado 1500 and GMC Sierra 1500. In developing these pickup trucks GM felt diesel fuel economy was its top priority. That has changed according to Muscle Cars and Trucks.

GMC and Chevy half-ton pickups with the diesel option already lead their class for fuel economy. A Chevy Silverado 1500 4 x 2 achieved 33 mpg highway and 23 mg city driving. The half-ton GMC Sierra scored a little lower at 30 mpg highway and 23 mpg city.

Though virtually identical, the differences are attributed to the GMC truck typically weighing more. This is because of the extra options being standard equipment. This adds weight which lowers fuel economy.

Higher Tow Ratings Over Fuel Economy

“We’re actually looking at upgrading some of the materials around the engine to see if we can maybe raise our towing rating,” says GM assistant chief engineer of diesel engine controls John Barta. “We do know that 95% of our light-duty customers don’t tow over 9,000 lbs. There was a conscious decision to maybe not go after the towing but go after the fuel economy. We realized that our towing rating is hitting 95% of the customers we have.”

As of now, a Duramax diesel engine in a half-ton GM pickup has a maximum towing rating of 9,000 lbs. “Even though it’s nice to brag about big numbers, in reality, light-duty customers are not towing that large with their trucks,” says Barta. “We think we hit the right balance with delivering class-leading fuel economy and still be able to tow as a light-duty customer.”

Inline-Six More Balanced Tow Engine

There are many who feel that the inline-six configuration produces a balanced engine aiding fuel economy. Without the need for NVH aids that rob fuel economy like balance shafts. This provides a leg-up over other engine platforms. “We don’t have as much rotating mass that we have to support that a V6 does,” says Barta.

He says the packaging is better with this engine platform, “Because the width is smaller, we have a lot of room on either side of the engine. One of the things we’ve done that our competitors with a V6 can’t do is we’ve been able to pull our after-treatment systems up very close to the side of the engine, very close to the outlet of the turbo. The heat from the turbo is warming up our exhaust systems and our exhaust systems need to run hot to be efficient. We can use less fuel and less energy to get our exhaust systems hot, and meet our emissions quicker.”

The 3.0-liter Duramax diesel engine currently produces 277 hp and 460 lb-ft of torque in either the GMC or Chevy half-ton pickups. 

Other changes coming in 2021 include improvements to the center stack in the interior. In 2022 we should see the new Silverado ZRX debut to compete with Ford’s Raptor. And, with the negative reaction to the front end of the T1-platform trucks, we may see revised grilles. So, there is a lot that will be changing around the GM pickup trucks over the next two years.