Everything To Know About Chevrolet's 6.6L Duramax Diesel Engine

Diesel engines are synonymous with pulling power, and the Chevrolet 6.6-liter Duramax Diesel isn't an exception. Whether you're hauling large equipment, cattle, or a sizeable 5th wheel, diesel is the go-to for enhanced torque. So, what makes Chevrolet's Duramax unique, and why might you consider this option for your heavy-duty truck?

The Duramax was born out of necessity as Chevrolet struggled against its competitors at the start of the twenty-first century. The history behind the legendary Duramax diesel began when Chevrolet sought a partnership with Isuzu, who has been known for their diesel engine designs for decades. The first Duramax diesel was available in 2001, along with the automaker's HD diesel models.

While there have been regular updates to the Duramax's design, materials, and capabilities, the last seven years have seen the most remarkable changes. Specifically, in terms of total torque, Duramax is now comparable in specifications to some of its traditionally stronger competition.

According to Chevrolet, the 6.6-liter Duramax turbo diesel features eight cylinders with a displacement of 403 cubic inches and comes equipped with a turbocharger for added performance. Following a redesign in 2017, Chevrolet strengthened parts of the engine, such as the cylinder block, to support greater power output. Some reinforced components include enhanced cylinder heads made from cast aluminum and a more resilient steel camshaft.

Diesel engines don't use spark plugs like gasoline engines, so compression ratios must be much higher to facilitate combustion. The 6.6-liter Duramax produces a 16.0:1 compression ratio, comfortably in the mid-range of typical direct injection systems.

One of the notable features of the Duramax is it can achieve near-peak torque at only 1,600 rpm. Since torque is essentially the force that turns the truck wheels from a stop, the more power you get at lower RPMs, the better. Getting that camper or boat trailer rolling towards the lake is no easy feat, but with enough torque, you might forget you're pulling anything.

The new specifications on the 2024 Chevrolet Silverado HD include a bump of 25 horsepower up to a total of 470 hp at 2,800 rpm. The torque has also seen a noticeable increase of an additional 65 lb-ft for an overall 975 lb-ft. Chevrolet's prior update to the Duramax was launched in 2017, so the newly upgraded specifications are welcome considering the potent alternate options of Cummins and PowerStroke.

According to Chevrolet, the newest Duramax has also seen changes to the turbocharger, enabling enhanced performance while producing less audible noise when at a stop. For those unfamiliar, turbochargers increase the engine's capability by forcing air through the system. An influx of pressured oxygen gives the Duramax more than enough airflow to boost its output.

Considering the emergence of the 2024 Chevrolet Silverado EV pickup, it is unclear what changes Chevrolet has in store for the future of the Duramax. However, ranchers, contractors, and weekend warriors towing the family boat need the sustained power that only diesel engines like Duramax currently provide.