2020 Chevrolet Silverado 1500 Diesel Review

Craig Cole
by Craig Cole

The Chevrolet Silverado 1500 has received some minor enhancements for 2020.

Following its complete overhaul last year, the truck now offers improved towing capability and the broader availability of its alpha-dog 6.2-liter engine. The smaller 5.3-liter V8 with Dynamic Fuel Management is now offered with an advanced 10-speed automatic transmission, a welcome upgrade. Plenty of smaller improvements have been made as well.

But unquestionably the headline-grabbing feature for this latest model year is the availability of an all-new diesel engine. GM will now sell you a Silverado 1500 with an oil-burning straight-six bolted between its front fenders, a powerplant that melds ample capability and impressive refinement with blockbusting efficiency and more-than-respectable performance.

3.0-Liters of Fury


Engine: 3.0-liter diesel inline-six
Output: 277 horsepower, 460 pound-feet of torque
Transmission: 10-speed automatic
U.S. Fuel Economy (MPG): Not yet rated
CAN Fuel Economy (L/100 km): Not yet rated
U.S. Estimated Base Price: $45,685, including $1,595 for delivery

A brand-new modular design, this turbocharged engine has a lung capacity of 3.0-liters spread across half a dozen cylinders all arranged in a neat little row. Compared to the more popular V6 configuration, that classic inline layout is making a comeback these days thanks to slightly better efficiency and its inherent smoothness.

But now for some of this powerplant’s finer points. Starting with the basics, it’s built around a deep-skirt aluminum block with seven nodular-iron main bearings for enhanced durability. That foundation supports a rugged forged-steel crankshaft to which are attached forged connecting rods. Sliding up and down inside the bores are hypereutectic aluminum pistons with thick crowns and a reinforced top ring for added durability.

As expected, the head is cast of aluminum and sports a duet of camshafts, tubular units that operate four valves per cylinder. Those bump-sticks are chain-driven from the rear of the engine, as is the variable-flow oil pump, which is spun by a small, cogged belt operating in the oil pan. Driving these components from the engine’s bell housing end supposedly improves refinement and packaging. Remember, inline sixes are longer and narrower than V6s, which makes them challenging to fit in many engine bays. This is a major reason the V-type configuration has been dominant for decades.

The 3.0-liter Duramax’s compression ratio clocks in at a healthy 15-to-1. Providing the boost is a variable-geometry turbocharger with a maximum output of 29 PSI.

Feeding that pressurized air into this engine is a variable intake manifold with dual ports for each cylinder. This design improves responsiveness across the rev range.

A common-rail fuel-injection system delivers precise amounts of diesel to each cylinder exactly when required. Operating at more than 36,000 PSI (2,500 bar) this system can fire each injector up to 10 times per combustion cycle for reduced noise and harshness.

Improving cold-weather performance is a GM feature called Active Thermal Management. It directs coolant to certain parts of the engine first to speed warm-up. Ceramic glow plugs are also included. They heat up faster and get hotter than conventional ones. This means the latest Duramax should be able to start without issue even at 40 below zero (-40 C).

And what’s the result of all this fancy engineering? The 3.0-liter Duramax diesel provides an SAE certified 277 horsepower and 460 pound-feet of torque, 95 percent of which is available at just 1,250 rpm. These should be best-in-class figures, at least until the latest Ram 1500 EcoDiesel becomes available later in the summer. The Gen 3 version of that engine should deliver 260 horsepower and 480 pound-feet.

For reference, the 3.0-liter Power Stroke offered in Ford’s F-150 is similarly muscular, if slightly behind these rivals in output. It’s rated at 250 ponies and 440 pounds of torque.

The Drive

The second you fire this engine up you know it’s something special. GM’s 1.6-liter four-cylinder engine earned the nickname “whisper diesel” because of its impressive refinement. Smooth and hushed, this truck powerplant is a more-than-worthy successor.

Thanks to perfect primary and secondary internal balance, inherent advantages of the inline-six configuration, this truck remains polished even when working hard. Scarcely any vibration can be felt from this powertrain whether it’s at tick-over or wound out.

And thanks to its prodigious low-end torque, there’s rarely a need to bury the accelerator. This 3.0-liter Duramax moves the full-size Silverado 1500 with verve; it’s surprisingly ferocious. The truck gets up to speed with ease, its standard 10-speed automatic transmission seamlessly handing off from one gear to the next, keeping the engine in the chunky part of its powerband.

As for capability, diesel-powered Silverados should be able to tow up to 9,300 pounds, a bit less than the 11,400 pounds a Power Stroke-equipped F-150 maxes out at. But honestly, you’re not going to want to drag anywhere near that much weight with the Ford as it would barely be able to move. As memory serves, the F-150 feels noticeably less vigorous than then this new Duramax-powered Silverado.

Diesels are inherently more efficient than gasoline-burning engines. There are multiple reasons for this, including their often significantly higher compression ratios and more energy-dense fuel. At this point, the Duramax-powered Silverado 1500 has not been rated by the U.S. EPA, but in its thriftiest form, I’m convinced it will deliver at least 30 miles per gallon on the highway. This is a figure diesel-equipped F-150s already deliver.

Demonstrating the efficiency of this oil-burning powertrain, GM set up a fuel-economy driving loop for members of the media to see how far they could push Silverado. Mid-40-mpg figures were not uncommon on the leaderboard. Indeed, this truck seemed to have no issue getting into the high-30s without much effort. It will be interesting to see what it’s officially rated at.

The Verdict: 2020 Chevrolet Silverado 1500 Diesel Review

GM’s brand-new 3.0-liter Duramax diesel engine is a little gem. Refined and economical, it will be offered in LT, RST, LTZ and High Country Silverado models.

But what good are all those benefits if nobody can afford to buy one? Another feather in this engine’s cap is its affordability. The price increase for diesel power is just $2,495 when upgrading from the 5.3-liter V8. In models equipped with the 2.7-liter turbocharged four-cylinder engine, the upcharge is a bit more, though still reasonable at $3,890.

Look for diesel-powered 2020 Silverado 1500s at dealerships starting in September.

Discuss this story on our Chevrolet Silverado Forum

Craig Cole
Craig Cole

Born and raised in metro Detroit, Craig was steeped in mechanics from childhood. He feels as much at home with a wrench or welding gun in his hand as he does behind the wheel or in front of a camera. Putting his Bachelor's Degree in Journalism to good use, he's always pumping out videos, reviews, and features for AutoGuide.com. When the workday is over, he can be found out driving his fully restored 1936 Ford V8 sedan. Craig has covered the automotive industry full time for more than 10 years and is a member of the Automotive Press Association (APA) and Midwest Automotive Media Association (MAMA).

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