Car Reviews Truck of the Year

The 2020 GMC Sierra 1500 Will Make You Question Why Light-Duty Trucks Need V-8s

GMC's updated full-size truck is a 2020 Truck of the Year finalist

GMC's updated full-size truck is a 2020 Truck of the Year finalist

Pros:

  • New gasoline engine
  • New diesel engine
  • Slick 10-speed

Cons:

  • Dull interior design
  • Mediocre interior materials
  • Eye-watering prices

“Between the new 3.0-liter Duramax diesel inline-six and the 2.7-liter gas-sipping inline-four,” senior features Jonny Lieberman said, “you have to question why light-duty trucks need V-8s.”

We’ll go even further than Lieberman’s commendation. By the end of our week of testing, these two new engines in the Sierra 1500’s retuned platform had reached a definitive answer: “You don’t need a V-8.” It’s just a question of which smaller engine best suits your hauling and towing needs.

Read about Car, SUV, and Truck of the Year contenders and finalists HERE.

For the lightest-duty stuff, the turbo 2.7’s 310 hp and 348 lb-ft is plenty. But among pickup people, the new Duramax (an option that adds between $2,495 USD and $6,375 USD depending on trim) should be cause for confetti-flying celebration, churning out 277 hp and 460 lb-ft of truck-important torque while delivering 3-4 more city and 4-8 more highway mpgs than the 2.7-liter.

Between its turbodiesel torque and new 10-speed automatic (the 2.7 gas has eight gears), the Duramax tows even better than it goes. Compared to the similar Ram 1500 Rebel EcoDiesel (with 20 more lb-ft) the Sierra is 7 percent quicker to 60 mph and 9 percent quicker when pulling the same 7,500-pound (3,402-kg) trailer.

You sense it subjectively, too. Markus: “This truck seems to pull this trailer more easily than the EcoDiesel did.” Evans: “The engine feels like a restless horse straining at the reins. It’s definitely quicker than the Rebel and even smoother. The Duramax is a torquey little thing—this engine is the star of the show here, no doubt.”

It’s also a comforting halfway house for anyone new to diesels. Aside from its beefy torque, it has the gentlemanly manners of a gas engine. Walton: “The engine is so very not diesely. Where’d the clacking go?” Everybody noticed its uncharacteristic quietness and smoothness. Markus: “I am a little amazed at how little this engine sounds like a diesel.”

Struggling to find anything to criticize, the best Markus came up with was, “I pity the mechanics who ever have to work on this; I opened the hood to get a look at this inline-six and could not see any of the engine.” That shrouding is partly why it’s so quiet.

Although the truck that surrounds the Duramax is a carryover from last year’s debut, GMC retuned the front coil and rear leaf-spring suspensions. GMC also festooned the truck with features and options, highlighted by the CarbonPro Edition, which includes a (very tough) carbon-fiber bed (with 12 tie-downs). It adds between $6,410 USD and $10,960 USD to AT4 or Denali models, which also get GMC’s MultiPro mini tailgate-within-a-tailgate that, when deployed, extends the 6-foot bed to a nominal 8. That pricing is a mighty tough sell.

There’s also encyclopedic monitoring of the truck’s various vitals: At one point, I scrolled through its data stream and noted the Sierra’s air filter life (95 percent), oil life (76 percent), fuel range (464 miles (747 km)), transmission fluid (198 degrees), fuel filter life (93 percent), brake pad life (97 percent front, 98 percent rear), plus all four tires’ pressures, DEF level, roll and pitch angles, trailer brake gain, following distance, and fuel economy. Who needs a mechanic to diagnose an issue?

On the road, the Sierra both rides and handles well, with even our Duramax version benefiting from lighter weight on the front axle. “I had a sense of this vehicle being nimble in much the same way the 2.7 was,” Markus said.

But where the Sierra stumbles is its drab interior. Understand, everything you need is there, including an available head-up display. It just looks dated. And unfortunately, that’s what you see every morning.

And although the Sierra had its proponents, especially in the great-looking AT4 trim, with its great tech and 10-speed automatic. But many of the judges were stopped cold by that interior.

2020 GMC Sierra 1500 AT4 (CrewCab 4WD)
Base Price/As Tested $60,310/$65,800
Power (SAE net) 277 hp @ 3,750 rpm
Torque (SAE net) 460 lb-ft @ 1,500 rpm
Accel, 0-60 mph 7.5 sec
Accel, 0-60 mph (loaded) 8.7 sec*
Accel, 0-60 mph (towing) 18.0 sec**
Quarter Mile 15.7 sec @ 86.2 mph
Quarter Mile (loaded) 16.6 sec @ 82.0 mph*
Quarter Mile (towing) 21.0 sec @ 63.7 mph**
Braking, 60-0 mph 130 ft
Braking, 60-0 mph (loaded) 132 ft
Double Lane Change Time 4.1 sec
Davis Dam Frustration 21.0 sec @ 1,450 ft***
Cruise Control 65-mph Overrun 3.2 mph
EPA City/Hwy/Comb 22/26/24 mpg
Key
* 1,500-lb payload | ** 7,500-lb trailer
*** 35-55-mph uphill acceleration with 7,750-lb trailer