GM's 2.7-liter Pickup Engine Comes Up Short in Real-world MPG Test

Steph Willems
by Steph Willems
gms 2 7 liter pickup engine comes up short in real world mpg test

You’ve read no shortage of commentary about General Motors’ new truck engine on these digital pages — from the 2.7-liter four-cylinder‘s impressive on-paper power figures (310 hp, 348 lb-ft), to the continuing rivalry between GM and Ford, to the rather slim fuel economy gap separating it from its eight-cylinder stablemates. You’ve also read about GM’s reluctance to mention that the engine is, in fact, a four-cylinder.

Now, two real-world tests prove that your mileage may indeed vary — and 2.7 Turbo owners might not be happy with the results.

Car and Driver claims its recent test of a 2019 Chevrolet Silverado RST double cab 4×4 left them wanting more. More MPGs, that is. In a run through a 200-mile, 75 mph highway course, the 2.7-liter pickup not only fell below the vehicle’s EPA rating, it also returned worse fuel economy than a similar model equipped with a 5.3-liter V8 performing the same test.

Worse still, the 2.7-liter tied the gas mileage returned by a truck powered by GM’s revered 6.2-liter V8.

While GM’s 5.3- and 6.2-liter V8s recently saw the addition of cylinder-juggling Dynamic Fuel Management, the 2.7-liter’s combination of small displacement, turbocharging, and a host of fuel-saving measures conspires to return an EPA combined rating of 20 mpg in the particular truck tested by Car and Driver, compared to the 5.3-liter’s 18 mpg. On the highway, both trucks rate a 22 mpg figure.

In a high-speed highway slog that didn’t line up with the EPA’s more tepid testing cycle, C&D discovered that the “2.7T averaged 18 mpg over the 200-mile test, a 28 percent drop from the 21 mpg we observed in the 5.3-liter RST Crew Cab, which was a full 314 pounds heavier.”

The publication notes that, at 75 mph, the 2.7’s turbo was likely online, helping push the wall-faced Silverado through the resistant atmosphere. At a lower speed, like that seen in an EPA test, it’s likely the engine’s turbocharger would sit idle, returning the operator a higher MPG figure.

“Despite its 6.2-liter V-8 having more than twice the displacement and 110 additional horsepower—it also gets a 10-speed automatic rather than the 8-speed—the Denali managed to tie the 2.7T’s 18-mpg HFE result,” the publication noted. “The only half-ton pickup we’ve tested that has done worse on the HFE test is a 2017 Toyota Tundra SR5 fitted with the TRD Off Road package. It got 17 mpg.”

It also noted that a test of the Ford F-150 Raptor returned a result identical to the 2.7-liter GM product. It’s too bad the publication didn’t state what the temperature was during the two Silverado tests, as lower air temps reduce a vehicle’s fuel economy to some degree. The same goes for the other tested vehicles. We don’t know exactly where C&D tested these vehicles and on what day.

Still, recording significantly worse mileage in a four-cylinder versus a V8 is a jarring event, and one that might provide food for thought for prospective GM truck buyers.

[Images: General Motors]

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  • JoDa JoDa on Jan 22, 2019

    Car and Driver? What mileage did Truck and Granny get?

  • Jerome10 Jerome10 on Jan 23, 2019

    This doesn’t seem too bad. I just drove cross country in a new Lexus NX200t with a puny little 2.0L turbo 4 and my mpg was 21.5. And that car is half the size and half the capability and probably 2/3 the power of this Silverado. So yeah, put me in the small turbo engines suck bandwagon, at least on cars with a big front profile. My old GTI was fine and usually darn close to EPA. The BMW turbo 6s I get time in have actually been excellent. They work on cars since they’re not pushing so much air? It’s extra insulting when you could have equal or better economy plus a smoother and less complicated engine. V6 Lexus or a V8 Silverado. Maybe GM shouldn’t have offered this truck. I don’t know. But they’re certainly far from alone in the bad-mpg small turbo 4 cylinder department.

  • Jim Bonham Thanks.
  • Luke42 I just bought a 3-row Tesla Model Y.If Toyota made a similar vehicle, I would have bought that instead. I'm former Prius owner, and would have bought a Prius-like EV if it were available.Toyota hasn't tried to compete with the Model Y. GM made the Bolt EUV, and Ford made the Mach-E. Tesla beat them all fair and square, but Toyota didn't even try.[Shrug]
  • RHD Toyota is trying to hedge their bets, and have something for everyone. They also may be farther behind in developing electric vehicles than they care to admit. Japanese corporations sometimes come up with cutting-edge products, such as the Sony Walkman. Large corporations (and not just Japanese corporations) tend to be like GM, though - too many voices just don't get heard, to the long-term detriment of the entity.
  • Randy in rocklin The Japanese can be so smart and yet so dumb. I'm America-Japanese and they really can be dumb sometimes like their masking paranoia.
  • Bunkie The Flying Flea has a fascinating story and served, inadvertently, to broaden the understanding of aircraft design. The crash described in the article is only part of the tale.