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2020 GMC Sierra 1500 First Drive: Is the Diesel a Do or a Don't?

3.0L Duramax Diesel Is Worth All the Anticipation

What is it?

Like its Chevrolet Silverado 1500 stablemate, the 2020 GMC Sierra 1500 is a full-size pickup truck that is available in crew-cab, double-cab and regular-cab configurations. No surprises there. For 2020, there are some new trim options and, most notably, a new powerplant. Along with the previously available gas engines, the Sierra 1500 now offers an optional turbocharged diesel inline-six engine. The hotly anticipated 3.0-liter Duramax diesel engine option has been talked about for over a year. Recently, it appeared briefly on the 2019 Sierra options sheet, but it was abruptly removed when it became clear the certification process would be delayed.

This engine differs from other half-ton diesel pickup engines because it's a straight-six instead of the usual V6. Since it's longer, it takes up more engine compartment space. But engines with this layout tend to run smoother and produce more torque. The Duramax's power ratings support this: 277 horsepower and 460 lb-ft of torque. GMC pairs this engine to a 10-speed automatic transmission.

2020 GMC Sierra 1500

Why does it matter?

Every 2500 and 3500 HD pickup truck has a diesel engine option, and they're always in demand despite the extra upfront cost. The same has not been true of the 1500 series "half-ton" segment. For years there wasn't a single choice until Ram reintroduced a diesel in 2014.

Diesel engines are popular among truck buyers because they excel in two key areas: They make abundant torque for easier towing and offer better overall range and fuel economy. They are especially good at doing both at once by providing respectable fuel economy and range while towing.

2020 GMC Sierra 1500

What does it compete with?

Ford sells a 3.0-liter Power Stroke turbodiesel V6 engine that makes 250 hp and 440 lb-ft of torque. Fuel economy in combined city/highway driving is rated at 25 mpg for two-wheel-drive models and down to about 22 mpg for four-wheel-drive versions. Towing is pegged at a maximum of 11,400 pounds.

Ram began selling a 3.0-liter EcoDiesel in 2014, and sales were brisk until it was pulled from the lineup due to problems with emissions certification. It's finally back in the 2020 Ram 1500 and offers strong competition with ratings of 260 hp and 480 lb-ft of torque. It's also rated to tow as much as 12,560 pounds.

The Sierra, with the new diesel engine, can tow up to 9,100 pounds. Is this a huge problem for GMC? In terms of bragging rights, absolutely. But 9,100 pounds is still plenty of capacity. And if you really want maximum towing, you can get the gasoline V8 for up to 12,100 pounds. The Duramax engine exists to provide superior everyday fuel economy. The EPA estimates it'll get 24-26 mpg in combined driving, depending on configuration.

2020 GMC Sierra 1500

How does it drive?

The days of trading ride comfort and handling for the hauling and towing power of a pickup are gone. The Sierra 1500 is so smooth and quiet that we had to pull over after a mile into our evaluation to check the badge and make sure we were driving a Sierra with the Duramax engine. The diesel and 10-speed automatic provide smooth and seamless power in all situations. There is no wind noise, little engine noise and minimal tire noise — even in the lifted AT4 trim level.

Visibility in the 1500 is good, although it lacks the giant square windows of its big heavy-duty siblings. It's still easy to see out of. It's also surprisingly nimble and stable. We've been in Cadillacs that had a more punishing ride quality.

Don't think that just because the Sierra is quiet and plush, that it isn't capable. The AT4 trim equips the Sierra with a 2-inch suspension lift and optional all-terrain Goodyear Wrangler DuraTrac tires. It will happily ramble over rocks or through the mud, so you know it won't have any trouble hauling a couple of dirt bikes down a dirt road to wherever you plan to do your On Any Sunday remake.

2020 GMC Sierra 1500

What's the interior like?

We've given Chevy a hard time about the Silverado's less than thrilling interior. GMC steps it up, but not enough. While the materials are soft-touch, and there are a few pops of color and texture, the Sierra just doesn't push the interior design, even in the high-level Denali. It's monolithic and monochromatic, like driving the artifact from 2001: A Space Odyssey — shiny, vertical and black.

Ford and Ram are doing more in this space when it comes to visual appeal. However, the Sierra's seats are comfortable and available with heating and ventilation. The controls are easy to understand and easy to get to, which isn't always the case in a big-truck interior. The center console could fit a watermelon, and the back seats are large enough for your largest friends.

2020 GMC Sierra 1500

How practical is it?

If you ever fret about towing, GMC's ProGrade trailering system will cure your ulcers and may inspire you to take the boat out more. A combination of cameras, optional tow mirrors, parking brake assist (for easier hitching), and an integrated trailer brake controller make dangling a trailer as easy as driving without one.

You can bring up a combination of 15 different camera angles on the center touchscreen to keep an eye on every corner of your payload. And if you get the optional head-up display, you can keep those towing camera displays up while using the head-up display for other info, such as navigation directions. There's even an option for a camera that shows you the inside of your trailer. It takes all the guesswork out of changing lanes and turning corners, and it will make even experienced haulers breathe a sigh of relief.

Speaking of hauling, the Sierra has some nifty bed features, too. First is the previously available MultiPro tailgate, which you can lower as either a traditional one-piece or separate to create a handy step or a tailgate party hangout. Our only criticism is that having a hitch installed can interfere with deployment of the MultiPro tailgate's step position. Want some tunes? Add a built-in Kicker audio system to the bed, which GMC says uses the same technology as watercraft stereos, so you don't have to worry about shorting it out if you're partying in the rain or launching a speedboat.

If you opt for the Sierra's CarbonPro bed, you get to be an early adopter of some very cool technology. Ford may have aluminum, but GMC is going carbon fiber. The molded bed is a mix of cut carbon and resin, and GMC says it is more abrasion- and impact-resistant than any of its competitors.

2020 GMC Sierra 1500

What else should I know?

The 2020 Sierra 1500 is a well-designed truck with several unique options. The Denali and AT4 are high-level choices, but the new Elevation edition is an attractive vehicle at a lower price point. GMC doesn't have the bragging rights on numbers for its 1500, but it has an edge on technology and refinement.

2020 GMC Sierra 1500

Edmunds says

We're believers in the idea of a 1500 series truck with a diesel engine, and the smooth-riding 3.0-liter Duramax in the GMC Sierra 1500 might very well win over new fans to diesel driving.

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