Diesel do nicely: GM’s full-size SUVs get 3-litre Duramax power

Following a two decade hiatus, GM reintroduces the diesel engine to its big 8-seat haulers in hopes to break the stereotypes & expand the demographics.

The full-size SUV segment has a new dimension with the arrival of diesel power for the Chevrolet Tahoe and Suburban as a complement to the standard 5.3 and 6.2-litre gas engines. 

The two body-on-frame models may now be specified with the same turbocharged, 3-litre Duramax power unit that debuted in the 2020 Chevrolet Silverado and GMC Yukon, boasting 277 HP, 460 lb-ft of torque and class-leading combined fuel economy.

The Tahoe 4WD’s consumption figure of 10.6L/100km (22mpg), for example, is a 26% improvement over the standard 5.3-litre gas motor. The towing capacity remains competitive, with the diesel down only 200 lb on the 5.3, at 8,000 lb (3,629kg) for the Tahoe 4WD.

The arrival of the inline-six marks the first time since 1999 that a full-size GM SUV has been available with diesel power. It’s currently unique in the segment, but GM is confident that the buyers are out there. According to Doug Kenzie, Chevrolet Canada’s national marketing manager for trucks and full-size utilities, customers want more efficient options without sacrificing capability and durability.

“We think that full-size utility customers will really appreciate this diesel,” he says. “Typical diesel customers tow a little more or drive longer distances, but I really believe we can break some stereotypes and expand the demographics that we see for diesels. This engine is quiet but still has great horsepower and fantastic torque.”

We want to change the perception that diesels are noisy. Just idling in your front driveway, you can hardly tell that this is a diesel engine.

John Barta, GM’s regional assistant chief engineer for diesel
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As in the pickups, the Duramax is paired with a 10-speed automatic transmission and has switchable stop-start technology to shut off the engine at stoplights and in other stop-go situations. Changes to the 3-litre motor for its installation in the SUVs included new software and additional noise abatement measures.

“A cover on the front of the engine especially helps [to reduce noise] when the engine is idling,” says John Barta, GM’s regional assistant chief engineer for diesel. “We want to change the perception that diesels are noisy. Just idling in your front driveway, you can hardly tell that this is a diesel engine.”

2021 Chevrolet Tahoe LS with the 3.0L Duramax Turbo-Diesel. Photo: GM

On the Tahoe and larger Suburban, the 3-liter Duramax turbodiesel is available in the LS, LT, RST, Premier and High Country trims. For now, it’s not offered on the Tahoe Z71 (reviewed here) due to a fitment issue with the front fascia, but Chevrolet is said to be working on it. It was already available in Silverados of LT-spec and higher with the exception of the Trail Boss trim, but that fitment is thought to be on the way, too.

The last GM SUVs to offer diesel power were the Chevrolet Equinox and GMC Terrain, which had a 1.6-litre unit. They were dropped for 2020 after disappointing sales. As in those models, the Tahoe and Suburban’s diesels represent a premium option (an extra C$1,995 or US$995 in LS, LT, RST and Premier trim levels), but the company believes that the greater fuel-efficiency gains from a larger vehicle will encourage more customers to make the switch.

Only 6% of Chevy’s full-size utility buyers in Canada had taken the diesel at the time of writing, but it wasn’t available from launch and Kenzie hopes the final share will lie in the 10-15% range. About 17% of Canadian light-duty Silverado buyers opt for the 3-litre Duramax.

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Graham Heeps
Based in Calgary, AB, Graham’s outlets include Autocar, Professional Motorsport World, Turnology.com and Electric & Hybrid Vehicle Technology. A lifelong motorsports fan, he’s a member of the Automobile Journalists Association of Canada (AJAC), the Guild of Motoring Writers and the Motor Press Guild, speaks German and collects Matchbox cars (at the same time).