2020 Chevrolet Silverado 1500 Duramax Diesel MPG Report After 1,000 Miles

Ram, Chevrolet and GMC have new diesel powertrains for their latest half-ton pickup trucks, and within the past few months, we’ve put both the 2020 Ram 1500 EcoDiesel and 2020 GMC Sierra 1500 diesel through fuel economy runs. Now, it’s the turn of the 2020 Chevrolet Silverado 1500 diesel over a roughly 1,000-mile, unloaded run. Though the Silverado 1500 and Sierra 1500 share the same turbocharged 3.0-liter inline-six-cylinder diesel engine, they have different fuel economy ratings partly thanks to unique aerodynamic profiles.

Related: 2020 Ram 1500 EcoDiesel MPG Report After 900 Miles

The Silverado 1500 diesel is EPA-estimated at 23/33/27 mpg city/highway/combined for 4×2 models and 23/29/25 mpg for 4x4s. The Sierra 1500 checks in at 23/30/26 mpg (4×2) and 22/26/24 mpg (4×4), with the highway figures providing the largest gap. These numbers compare favorably to the diesel half-ton offerings from Ram and Ford, as well.

My test vehicle was a 2020 Silverado 1500 RST double cab with a 4×2 configuration and a $48,685 price tag (including destination charges). The most expensive option was, of course, the diesel engine itself that adds $3,890 to the truck’s bottom line.

The Silverado 1500 Diesel’s Real-World Fuel Economy

The results were a reported 26.4 mpg from the truck’s trip computer, while our measurements indicated 27.4 mpg on a total of 37.41 gallons of diesel. I drove the Silverado on a long loop from Los Angeles to the San Francisco Bay Area, with other highway miles mixed in from both locales. The vast majority of the 1,026 miles were spent on highways at higher speeds — thank you, Christmas, for being one of the few things that can keep California free of traffic. Test conditions for the drive were mostly ideal with a little rain but mostly mild temperatures (between 40-60 degrees Fahrenheit). Speeds were kept to within 5-10 miles of posted speed limits, climate control kept on, tires filled to the manufacturer’s specifications and the windows kept up. Cruise control was used at times on flat ground to maintain a constant speed.

While 26-27 mpg is still impressive for a full-size pickup, the numbers did fall short of the estimated 33 mpg highway estimate.

There are a few reasons that this could be. Interstate 5, which most of the miles were driven on, has a higher speed limit (70 mph) than most highways, and higher speeds are not as efficient. The drive also featured quite a bit of elevation change, with a climb over the Tejon Pass in both directions, which sits at 4,144 feet.

In a shorter test, we found that the GMC Sierra 1500 beat both its combined and highway fuel economy estimates. This test seems to mirror our Ram 1500 test, which totaled 900 miles and was done at higher speeds with significant elevation changes. In that case, the Ram 1500 got 25.0 calculated mpg and 23.8 trip computer mpg (though it was also a 4×4, so it had lower estimates at 21/29/24 mpg).

As far as how the Silverado diesel drove, it was fantastic. The diesel hum was kept to a minimum, and the powertrain was responsive and smooth. The best thing I can say is that it drives like a gas engine most of the time, but its 460 pounds-feet of torque always feels close by when you want to dip into the power. The cabin does leave a bit to be desired — this was a lower trim level of the Silverado — but the powertrain is dead-on.

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