2021 Chevrolet Suburban Diesel First Test: The Most Efficient Full-Size SUV

Efficient full-size SUVs are like cheap wagyu beef. They simply don't exist. But when a punchy six-cylinder diesel engine is fitted under the hood, things change. The 2021 Chevrolet Suburban Diesel is rated at 20/26/22 mpg city/highway/combined, which makes it the most fuel-efficient four-wheel-drive full-size SUV in the market. Think about that for a sec.

A diesel Suburban is not novel, but the SUV hasn't been offered with an alternative type of engine for a long time. And although the diesel engine isn't as quick as the 5.3-liter engine, there are more pros than cons. We drove a 2021 Chevrolet Suburban Diesel High Country and took it to the track to compare its handling and performance against a Suburban with the base engine.

2021 Chevrolet Suburban Diesel: The Performance

With 277 hp and 460 lb-ft of torque, the Duramax turbodiesel l-6 engine is buttery smooth and elegantly refined. Like in the Chevrolet Silverado 1500 Diesel, the Duramax engine is quiet and pulls with confidence, getting torque to the tires via a 10-speed automatic transmission.

Given that nearly all of the torque is delivered at 1,500 rpm, the Suburban Duramax doesn't feel slow, either. The engine pulls nicely from the start, and the quick and smooth transmission shifts when it needs to and doesn't hunt for gears to achieve better fuel economy. Need more oomph? Simply press down the throttle, and the gearbox will downshift instantly. We've praised this transmission in the past—both in a gas Suburban and in a diesel Silverado—and we continue to be impressed by its performance and refinement.

Compared to the Suburban's gasoline-powered 5.3-liter V-8, the diesel is a bit louder, but it's hard to notice unless you're paying attention. Chevy fitted additional noise abatement materials under the hood to keep the ride quiet and serene. However, those with good hearing will pick up the common idling clatter of a diesel engine.

Like in the other Suburbans and Tahoes that we've driven, the magnetic ride control suspension coupled with the air ride adaptive dampers make the ride as smooth as possible in a truck this big. Despite the massive 22-inch wheels, the handling in corners and on the freeway feels controlled, though some of the big bumps and ruts on the streets of Los Angeles were noticeable in the cabin. Steering is light for a full-size SUV, but it feels accurate.

You might think of diesels as torquey engines that can tow a lot, and they can. But because the Suburban is already powered by punchy V-8 engines, the six-cylinder diesel doesn't tow as much as the 5.3-liter or 6.2-liter V-8s. The rear-drive Suburban Diesel can tow up to 8,000 pounds, where the four-wheel-drive model can pull 7,800 pounds. Payload capacity is rated at 1,625 and 1,538 pounds, respectively. In contrast, the standard V-8 can tow 8,300 and 8,100 pounds, respectively, and the 6.2-liter is rated at 8,200 and 7,900 pounds.

With our Vbox datalogger in place, a dragstrip to ourselves, and associate road test editor Erick Ayapana behind the wheel, we confirmed what we felt on the streets—the 2021 Chevrolet Suburban Diesel got from 0 to 60 mph in 8.5 seconds, which is 0.9 second slower than the 5.3-liter Suburban Z71 4x4 we last tested. The diesel crossed the quarter-mile mark in 16.6 seconds at 84.9 mph, which is 0.9 second more and 4.7 mph slower. Ayapana described the Suburban diesel as "a little lazy off the line," but said it had "otherwise smooth and strong power delivery."

Of course, very few people will drive the Suburban flat out, but a lot of us will brake harshly in emergency situations. Our diesel stopped from 60 mph in 115 feet on Bridgestone Alenza all-season highway tires, which is a great distance for a full-size SUV. Those numbers compare favorably to the 5.3-liter we tested, which needed 127 feet to stop despite weighing 236 pounds less, but then it was riding on trail-optimized 20-inch Goodyear Wrangler TrailRunner AT tires.

In terms of handling, road test editor Chris Walton had a hard time with the stability and traction control systems, as power cut off constantly during our figure-eight test. As such, it took 32.3 seconds at 0.47 g to complete.

 2021 Chevrolet Suburban Diesel: Price and Availability

LS, LT, RST, Premier, and High Country trims can be powered by the Duramax engine—that's all of the trims except the off-road-ready Z71 (alterations to its front end to optimize approach angle mean the longer inline-six doesn't fit). Upgrading from the 5.3-liter to the diesel adds $995 to the price of an LS, LT, RST, or Premier trims, which is a pretty good price considering all of the benefits. Since High Country models come standard with the more powerful 6.2-liter V-8 engine, ordering one of these with the Duramax diesel six-cylinder will net you a $1,500 discount.

The fair price and availability across the Suburban lineup makes the diesel engine an option worth seriously considering. A significant bump in fuel economy over the 5.3-liter V-8 (15/19 mpg city/highway for four-wheel-drive models), the 4WD Suburban Diesel's 20/26 mpg stands out in a big way. And a two-wheel-drive Suburban Diesel rated 21/27 mpg starts at just $53,990.

Our 4WD Suburban Diesel High Country crossed the checkout counter at $82,495, which is a bit high, but that included $7,400 in extras. The High Country Deluxe package was the most expensive—at $5,555 it adds adaptive cruise control, retractable steps, emergency braking, panoramic sunroof, the air ride adaptive suspension, and the trailer brake controller, among other features.

Should I Buy the 2021 Chevrolet Suburban Diesel?

It doesn't matter what your budget is—if you're looking for a Suburban, the Duramax engine is worth looking at. For less than a grand you will be getting more torque and better fuel economy without much sacrifice in performance. And who doesn't like that?

Wagyu beef may be decades away from becoming affordable, but with the Duramax engine ushers in a new era of fuel-efficient full-size SUVs.