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Driving the Diesel-Powered 2021 Chevrolet Suburban: The One to Buy

Chevy’s first diesel Suburban in more than 20 years delivers the goods.

LOS ANGELES—When it came time to test a 2021 Chevrolet Suburban with its new 3.0-liter Duramax diesel, I insisted to our ed-in-chief that, as the owner of a gracefully aging diesel Suburban of 1983 vintage, I was by far the most qualified Automobilian to review it.  My editor's response cannot be printed here; suffice it to say, it began with "bulls" and ended with "hit".

Apparently, he was under the nonsensical impression my smoke-belching Radwood-era family truckster has nothing in common with the latest and greatest in compression-ignition technology. If there's one thing I know about my boss, it's how to wear him down. Two dozen emails and text messages later, the assignment to test the 2021 Chevrolet Suburban diesel was mine!

Actually, OK, I made up all of that. But it's the kind of exchange the boss and I could've easily had. Mostly, I feel the need to endeavor to prove my 38-year-old Suburban, with its gurgling 6.2-liter V-8, is functionally identical to the brand-new 2021 Chevrolet Suburban diesel. Watch me work, people.

2021 Chevrolet Suburban Diesel Test:  All About the Fuel Economy

Let us start with the 2021 Chevrolet Suburban Duramax diesel's reason for existing, which is the same as my '83: Fuel economy. General Motors first introduced the diesel powered-Suburban in 1982, when the gasoline-fueled choices included 305 (5.0-liter) and  350 (5.7-liter) V-8s that returned around 12 miles per gallon, and a 454 (7.4-liter) engine that consumed fuel almost as quickly as you could pump it into the tank. The diesel improved those numbers by around 50 percent. Even with 38 years and 200,000 miles on the clock, my Suburban returns mid-teens in the city and 20 at its loping highway pace.

With automakers addressing pressure to improve fuel economy, it's not surprising history repeats itself. Today's gas-powered Suburbans have EPA combined economy figures in the 16-18 range, while the new diesel is rated at 21 city/27 highway/23 combined with two-wheel drive, and 20/26/22 with four-wheel drive. And like my old Suburban, it keeps its promises: I averaged right around 21 mpg (including some towing, which we'll talk about soon), and it easily stretched into the mid-to-high 20s on the freeway.

Does that not prove the two diesel Suburbans are functionally identical? Of course it does!

2021 Chevrolet Suburban Diesel Test: Economy Without a Performance Penalty

Granted, back in 1983, getting such (relatively) good fuel economy meant giving up any semblance of performance. Diesels quickly earned a reputation for being smokey, smelly, and slow, and Suburbans like mine are a big part of the reason why. When I take my Suburban out, I rarely bother locking the doors—if anyone tries to steal it, I will catch them on foot.

Modern-day car buyers are unwilling to make such compromises, and with the new 2021 diesel Suburban, they don't have to. While it's not a rocketship like the 6.2-liter, gasoline-fueled Suburban I drove a few months back, it's quick enough, accelerating from 0-60 in 8.5 seconds, according to our colleagues down the hall at MotorTrend. For comparison, they tested a 2021 Suburban with the 5.3-liter gasoline engine, and they timed it to 60 in 7.6 seconds. And while the 2021 diesel Suburban is a lot quicker than my old one (as are delivery trucks, small dogs, and octogenarians with walkers), power delivery is similar: It is strongest off of the line but it feels a little pokier at highway speeds.

Actually, highway-speed acceleration in my Suburban isn't pokey so much as it's nearly nonexistent, thanks largely to the engine's lack of a turbocharger. (Yes, kids, there was a time when they made diesels without turbos.) Natural aspiration explains its improbably low horsepower rating of 135, and torque is a paltry 240 lb-ft, which is less than what you get from a modern Toyota Camry's V-6.

Happily, the state of the diesel art has improved greatly during the past 40 years. The 2021 Chevrolet Suburban's diesel produces 277 horsepower and a massive 460 lb-ft of torque (which just so happens to be the same torque output as the 6.2-liter gasser). Its 3.0-liter engine is an inline-six, just like a big-rig engine. Straight-sixes are inherently balanced, and the smoothness of the Suburban's new diesel stands in strong contrast to my old Suburban's V-8, which doubles as a seat massager.

And while my old Suburban roars, the new one merely grumbles. The idle is quiet and distinctly diesel-y, and under power it's louder than the gas engine, but not by much. As we moved between photo locations, I drove my old Suburban while fellow staffer Conner Golden followed in the new one, and he said he could hear my engine louder than his own.

2021 Chevrolet Suburban Diesel Test: Easier to live With

Waking up the diesel engine in my 1983 Suburban is a process: Key on, wait for the GLOW PLUGS light to go on, then off (a few seconds here in sunny California; half a day or so in snowy Vermont, as I've been told), then crank the engine. It usually lights right up, which is what you want, because its two batteries don't provide much more than a minute or so of cranking time. The modern-day Duramax makes it a lot easier: step on the brake and press the button. Pre-warming (if needed) and starting are automated.

Despite nearly four decades between them, the driving experience between the two Suburbans is closer than you might expect. The new Chevy Suburban steers and handles in a way that belies its massive size: It goes where you point it and keeps body-roll nicely in check as you corner. My '83 has one-finger-light steering that's free of both feedback and precision, but the heavy-duty suspension—it's a 2500 3/4-ton model—makes it every bit as steady, if not as smooth, as the new 'Burb.

2021 Chevrolet Suburban Diesel Test: Towing Time

My Suburban was purchased by a friend's family as a towing machine. It's semi-retired now, but it still has the mechanical trailer-brake controller, which is connected by a metal rod to the brake pedal. The 2021 Suburban diesel also has towing on its resumé, and Chevy was kind enough to send me one with an optional built-in trailer-brake controller, which is electric and neatly integrated into the dash rather than hanging down from it.

Towing capacity for a diesel Suburban with the max-trailering package is 8,000 pounds for two-wheel drive, and 7,700 pounds for my four-wheel-drive tester, which is lower than gasoline-powered Suburbans, presumably due to the engine's extra weight. I hooked up our horse trailer and loaded up our horse Aiden, which brought the total trailer weight up to about around 4,700 pounds.

You have to drive extra-smoothly when hauling horses so they can keep their balance, and the diesel's steady torque build-up, plus the 10-speed automatic's silky shifts, should have made it a magic-carpet ride for Aiden. But he was in a particularly feisty mood and seemed to be trying his best to destabilize the trailer. The Suburban took no notice; even with 1500 pounds of rocking-and-rolling horse, we felt no movement from the trailer until we stopped at a light. (Our other horse, Rugby, did the same thing when we towed him behind the gasoline-powered Suburban. Maybe they're Ford fans.)

The 2021 Chevrolet Suburban diesel we tested averaged 13.5 mpg on my hilly towing test-route. I drove the same route in a 6.2-liter gasoline Suburban, with a slightly-lighter load, and couldn't break 10 mpg. Part of my towing circuit is a particularly long and steep highway on-ramp, over which the new Suburban was able to accelerate to 60 mph without the need for full throttle. That's a far cry from my old truck, which can barely get itself up that on-ramp at 40.

2021 Chevrolet Suburban Diesel Test: A Few Final Reflections on Diesel Suburbans

With the trailer put away, I took the 2021 Chevrolet Suburban diesel out for one last spin and focused on a few odds and ends. There have been some complaints from our staffers about the new Suburban's interior, but I rather like it—I think Chevrolet makes good use of the Suburban's wide dash, spreading out the controls and making them easy to understand and operate. (My old Suburban is no slacker in that regard, either, though granted there are fewer controls, and fewer that still work.) I particularly like the push-button shifter, or perhaps I should call it a pull-button shifter, even though it appears to be made of recycled power-window switches.

I waited a while to look at the price; I know what the Big Three charge for diesels in their heavy-duty trucks, and why kill my diesel-fueled buzz? So, I was pleasantly surprised to see Chevrolet charges just $995 for the diesel option. At that price, it won't take more than a few road trips before the engine pays for itself.

By the time my week with the new diesel Suburban drew to a close, I was more convinced as ever that the two 'Burbs were practically conjoined twins. Granted, the new one is a much better machine. Let's face it, the 6.2-liter lump in my old Suburban (which morphed into a 6.5-liter lump and then a 6.5-liter, turbocharged lump) is a big part of the reason Chevrolet quit making diesel Suburbans in 1999 and waited more than 20 years to sell the next one.

And yet I still think Chevrolet's 2021 Suburban diesel and my old one are kindred spirits. Both are hard-working beasts of burden that get great fuel economy. I wouldn't want an old Suburban without the diesel engine, and I can't see buying a new Suburban without it, either.

See, boss? They're exactly the same.

2021 Chevrolet Suburban Diesel Highlights

  • New 3.0-liter DOHC inline-six turbodiesel
  • Torque matches 6.2-liter V-8

2021 Chevrolet Suburban Diesel Pros

  • Excellent fuel economy
  • Quite reasonably priced compared to pickup-truck diesel options

2021 Chevrolet Suburban Diesel Cons

  • Interior isn't as fancy as the Ford Expedition's interior
2021 Chevrolet Suburban 4WD Premier Diesel Specifications
ON SALE Now
PRICE $70,590 (base)
ENGINE 3.0L turbocharged DOHC 24-valve diesel I-6/227 hp @ 3,750 rpm, 460 lb-ft @ 1,500 rpm
TRANSMISSION 10-speed automatic
LAYOUT 4-door, 7-passenger, front-engine, 4WD SUV
EPA MILEAGE 20/26 mpg (city/hwy)
L x W x H 225.7 x 81.1 x 75.7 in
WHEELBASE 134.1 in
WEIGHT 6,200 lb (est)
0-60 MPH 8.5 sec
TOP SPEED N/A