GM Lowers V8 Silverado Fuel Economy Ratings

General Motors' published ratings show the redesigned 2027 Chevrolet Silverado's V8 models return between 1 and 2 mpg less than the 2026 trucks.

Updated on Nov. 3, 2026 in Trucks

Bold flat-color editorial illustration of a centered V8 engine block beside a simple pickup cargo ramp on a plain red field, in economist-style geometric register. — General Motors published lower fuel economy ratings for V8 versions of the redesigned 2027 Chevrolet Silverado, showing a 1-2 mpg drop from the 2026 trucks, with the GMC Sierra expected to match. AI Illustration. Upload story photo >

Live Poll

Would fuel economy change whether you buy your next pickup truck?

GM published fuel economy ratings for V8-powered examples of the redesigned 2027 Chevrolet Silverado, which drop between 1 and 2 mpg across city, highway and combined measures compared with the 2026 models. The 2027 GMC Sierra is expected to carry the same V8 ratings as the Silverado.

Why it matters

The lower ratings affect buyers comparing the redesigned full-size pickups against prior-year trucks and rival models. Because the Sierra is expected to match the Silverado, the change extends across GM's full-size truck lineup.

Two-wheel-drive 5.7-liter Silverados are rated 16 mpg city, 19 mpg highway and 17 mpg combined, while four-wheel-drive versions lose an additional 1 mpg on highway and combined. The Silverado ZR2 with the 6.6-liter V8 drops highway by 3 mpg versus the prior model.

The players

General Motors

General Motors is the Detroit-based automaker that builds the Chevrolet Silverado and GMC Sierra full-size pickups and publishes their official fuel economy ratings.

Chevrolet Silverado

The Chevrolet Silverado is a full-size pickup from General Motors that has long been one of the best-selling trucks in the United States.

GMC Sierra

The GMC Sierra is General Motors' premium full-size pickup, sharing its platform and engine options with the Chevrolet Silverado.

The details

Most 2027 diesel Silverados also return 1 to 2 mpg less than the 2026 models. The figures were published in documents posted by GM Authority, and production of the new-generation trucks began in October 2026.

October 2026: Production of the new-generation Silverado and Sierra trucks began.
November 3, 2026: GM announced the 2027 Silverado V8 fuel economy ratings.

Roadmap

The downward revision comes as the redesigned full-size pickups enter production, with the Silverado's 2026 V8 ratings serving as the baseline. The new figures show that the V8 trucks are being rated less efficient than the prior generation in the same engine configurations.

Buyers choosing a V8 Silverado should expect roughly 1 to 2 mpg less fuel economy than the 2026 model in city, highway and combined driving. The lower ratings may matter most to drivers who tow or haul frequently with the larger engines.