Automotive News (subscription required) reported last Friday that both trucks with the 4.3-liter and 5.3-liter engines return worse fuel economy than their predecessors. The 2019 Silverado with the 4.3-liter V6 engine will return 16 mpg city, 21 mpg highway, and 17 mpg combined with a two-wheel drive truck, and 15/20/17 when paired with four-wheel drive. Those figures are down 3 mpg from 18/24/20 from a 2018 Silverado with the V6 engine and two-wheel drive, and down 2 mpg from a four-wheel drive truck, which returned 17/22/19 in the 2018 model year.
The 5.3-liter V8 engine returns an identical 17 mpg combined for the 2019 model year with four-wheel drive, down 1 mpg compared to the 2018 Silverado. 2019 Silverados with the 5.3-liter V8 will return 15/20/17 compared to 16/20/18 for last year’s truck.
The new 2019 Silverado Trail Boss models suffer even more with their off-road equipment. Both engines return fuel economy estimates of 14/18/16 with four-wheel drive.
We took a deeper dive into why the truck’s fuel economy numbers barely moved—or in the case dropped—back in September. It comes down to drag coefficient of an area (a multiplication of the drag coefficient value by the surface area). While aerodynamic efficiency increased by 7 percent in the 2019 Silverado and 2019 Sierra, the drag coefficient of an area worsened with the redesign. Basically, both trucks have a large hole they need to punch through the air. This creates more resistance as the trucks move at speed, which requires more energy to keep the moving. And that means they’re using more gasoline.
The same fuel economy story is present for both trucks’ new 2.3-liter turbocharged four-cylinder engine, too. Despite its dainty displacement, the engine only returns 20/23/21, which falls short of Ford and Ram’s larger, volume-selling engines.