GMC Sierra

Fuel economy, running costs and specs by model year

The GMC Sierra appears in this database in 5 model years, from 2016 to 2020, offered with diesel and gasoline and hybrid power. Combined economy ranges from 15 to 26 MPG across those years, with annual fuel costs of $3,100 to $4,700 at 15,000 miles.

Fuel economy by year

How it compares

Against the average standard pickup trucks 4wd in this dataset (about 18 MPG), the Sierra sits roughly 2 MPG above that mark on average, making it a relatively efficient choice for its class.

Five-year fuel cost

Fuelling a Sierra for five years at the EPA's 15,000-mile basis costs roughly $15,500 to $23,500, averaging about $19,500 across the versions here. That is the energy bill alone — it excludes insurance, maintenance and depreciation, which for most owners together exceed what goes into the tank.

The range within the range

Economy across the Sierra varies by about 11 MPG between its most and least frugal versions, which run on diesel and gasoline and hybrid. Engine size, turbocharging, drivetrain and even wheel size explain most of that gap, so when you shop a used Sierra check which version you are looking at before comparing its running cost to another car.

How it changed over time

Between 2016 and 2020 the Sierra's average combined economy improved from about 18 to 20 MPG. Redesigns, new engines and added hybrid or electric versions are usually what move the number, so the year you choose can matter as much as the model.

Best year for fuel economy

The 2020 Sierra has the strongest average combined economy in this database at about 18 MPG, while the 2019 is the lowest at about 17 MPG. If running cost is your priority, that is the year to target on the used market; later years may add equipment or safety features instead.

2020 Sierra at a glance

Use the comparison tool to set the Sierra against a rival, or go back to all GMC models.