The new and improved GMC Duramax Diesel

Quick notes

  • The GMC Duramax is the same price as GMC’s other engine offerings.

  • Diesel engines generally obtain far greater mileage than gasoline engines.

Back in the golden oldie days – you know, the 90s – diesel used to sell for almost half the price of gasoline. This is when manual transmission diesel Volkswagen Golf’s were to die for. Now, the price of gasoline and diesel trend pretty much the same. There have been occasions when diesel has been even more expensive than gasoline.

When the price of diesel rose, the interest of the general public in purchasing diesel engines for personal use pretty much ended. This was, however, not true for work trucks. These continue to be mostly diesel-powered.

The Duramax reintroduced

Capitalizing on this, and also to improve on some of their previous offerings, GM has launched a new and improved diesel engine called the Duramax targeted toward the light truck segment as an alternative to its Duramax 6.6 offered in larger trucks and commercial vans. The new inline-6 Duramax diesel is claimed to be the most powerful in its class. It’s a 3.0L, 277 horsepower engine providing 460 lb-ft of torque paired solely with a 10-speed automatic Hydra-Matic 10L80 transmission.

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The Duramax diesel is being offered at the same price as the 6.2L V8 gasoline engine which is great as normally diesel engines can cost an extra $5,000-$10,000.

Resurgence of diesel engines

The past few years we’ve seen a bit of a resurgence in diesel engines and interest in diesel engines for personal and smaller workhorse truck use. All of the debate and attention to climate change may have renewed interest in diesel engines as they generate fewer emissions. Diesel engines are still predominantly offered for and found in larger pickup trucks, but they are also generally offered in European crossovers and some sedans.

Back in the golden oldie days, so you know, the 90s, diesel used to sell for almost half the price of gasoline.

This renewed interest in diesel engines means that along with the GMC Duramax diesel engine, Ford is working on an improved version of their diesel offerings, and Dodge is currently working on a new diesel engine that will be offered for the Ram 1500 and Jeep Gladiator.


The GM Duramax is claimed to provide 33MPG highway and 23MPG city in RWD models, and 29MPG and 23MPG city in AWD models. Mileage has been as high as 40MPG when used with the stop/start technology.

There is a slight variance depending on specific configuration, but in the 2020 Silverado, the Duramax diesel engine has a towing capacity of 9,300 pounds with a maximum payload of 1,870 pounds.

The engine itself is made of hard-wearing materials such as iron cylinder liners in an aluminum engine block, blended silicon and aluminum pistons for limited expansion and greater heat resistance, and a forged steel crankshaft and connecting rods. These engines are built to last.

The new inline-6 Duramax diesel is claimed to be the most powerful in its class.

Other notable features include a driver option for stop/start fuel economy technology, an exhaust brake for increased driver control when towing downhill, and an active thermal management system which allows for greater operational efficiency. An aftermarket Duramax tuner can be installed to provide greater performance. Due to the recent release of the new Duramax, specs and details on exact performance enhancements by the tuner are not yet available.


Customer deliveries began just this past fall and the reviews are slowly trickling in. So far, no complaints about the engine, the power or towing capacity, but there are complaints about the interior of the trucks it’s offered in. Hopefully something GM will consider for the next model year.

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