GM announced fuel economy figures for the 2027 Chevrolet Silverado V8 models, and they all deliver worse mileage than 2026 equivalents.
The 2027 Silverado with the new 5.7-liter V8 rates at 16 mpg city, 19 mpg highway, and 17 mpg combined in two-wheel-drive form. Four-wheel drive drops highway and combined by 1 mpg each. These figures are down 1 mpg in city and combined ratings, and down 2 mpg in highway rating compared to 2026.
The 6.6-liter V8 in four-wheel-drive achieves 14 mpg city, 18 mpg highway, and 15 mpg combined. The off-road Silverado ZR2 drops to 13 city, 15 highway, and 14 combined. Both the standard and ZR2 ratings fall 1 to 2 mpg below 2026 levels.
The 3.0-liter inline-six turbodiesel also returns 1 to 2 mpg worse than last year in most trims, though diesel ZR2 city and highway mileage remains unchanged. Ratings for the turbocharged 2.7-liter four-cylinder have not been published.
The same figures apply to the 2027 GMC Sierra. Through the third quarter of 2026, Chevrolet sold 413,383 Silverados and GMC sold 252,639 Sierras, with production of the new generation beginning in October.