Yahoo Autos Tested: 2021 Chevrolet Tahoe Impresses with Diesel Power
Diesel engines are a tough sell in the United States, particularly since the 1970s when General Motors converted a gas V-8 to run on diesel for its Oldsmobile brand, which resulted in woeful reliability issues (mainly head bolts that couldn't withstand the rigors of diesel compression). The 2001 introduction of GM's powerful and stout Duramax diesel V-8 in its heavy-duty trucks—the result of a joint venture with Isuzu—helped make up for that earlier, ill-fated effort with Olds. But perhaps even more compelling for drivers who don't need near-big-rig levels of torque is the recent addition of a light-duty Duramax inline-six, which debuted in the Chevrolet Silverado 1500 and GMC Sierra 1500 pickups and has now begun to spread to all of GM's redesigned full-size SUVs, the first of which is the latest Chevy Tahoe tested here.
The turbocharged 3.0-liter Duramax is one of three engines available in the new Tahoe. Base models get a 355-hp 5.3-liter V-8, while the top-spec High Country is powered by a standard 420-hp 6.2-liter small-block. The diesel is the least powerful of the group, at 277 horsepower, but its 460 pound-feet of torque is the same as the 6.2's. Diesel engines are usually a costly upgrade because, among other reasons, they incorporate expensive exhaust-treatment systems that keep their sootier emissions in check. But that's not the case here. In High Country trims like our test vehicle, the diesel comes with a $1500 credit versus the big V-8. On lesser models, the engine is but a $995 line item and the cheapest Tahoe with the Duramax starts at $53,295; a loaded High Country starts at $69,395. Just be mindful that optional equipment can greatly inflate those starting figures, as exemplified by the $80K-plus price of our well-equipped example.
A diesel's prodigious torque output often implies a massive benefit for towing. But the 3.0-liter Duramax is rated to tow the least weight of the Tahoe's powertrains, although its still-strong 8200-pound rating in rear-drive models is but 200 pounds less than that for Tahoes equipped with the 5.3-liter V-8 and the optional Max Trailering package. The diesel also has an available trailering package, but it doesn't alter the truck's maximum capacity. If you're worried about a 200-pound buffer when towing, you probably need a more capable rig.
Where the six-cylinder Duramax shines is in its fuel efficiency. Based on current prices for fuel and diesel exhaust fluid—and assuming the EPA's combined estimates for rear-wheel-drive models of 18 mpg for the 5.3 and 23 mpg for the diesel—the Tahoe's Duramax option would pay for itself in about 80,000 miles. That break-even point is largely realistic, and it will shrink with the more miles spent on the interstate. We averaged 27 mpg on our 75-mph highway fuel-economy test, which is enough to give the diesel Tahoe a bladder-busting range of more than 600 miles. We haven't had the opportunity to test the highway legs of a Tahoe equipped with the 5.3-liter, but a GMC Yukon with the 6.2 got 20 mpg in the same test. Overall, our four-wheel-drive Chevy averaged 23 mpg.
