The following is a story from the Associated Press.
GM says the rear-wheel-drive diesel will get 33 miles per gallon on the freeway and 23 in the city.
That beats the diesel Ford F-150 by three mpg on the highway and one mpg in the city. An older version of Fiat Chrysler's Ram gets 27 on the highway and 20 in the city.
All the figures are estimates based on Environmental Protection Agency tests.
Silverado Executive Chief Engineer Tim Herrick says a new 3-liter inline six-cylinder diesel engine was designed for efficiency.
The lead could be short-lived. A new diesel Ram is coming but mileage hasn't been announced. Both new diesels reach showrooms in the fall.