The 2020 GMC Sierra 2500HD Base Regular Cab Long Box is equipped with a[n]Gasoline 6.6L V-8 engine that can produce ... 2500HD Base Regular Cab Long Box's fuel tank? How efficient is a 2020 ...

The SLT comes standard with GMC's versatile MultiPro ... mpg on our real-world highway fuel-economy route. We've tested a Sierra 2500HD Denali with the diesel engine, which returned 17 mpg on ...