Cadillac CT6

Fuel economy, running costs and specs by model year

The Cadillac CT6 appears in this database in 5 model years, from 2016 to 2020, offered with gasoline and plug-in hybrid power. Combined economy ranges from 17 to 28 MPG across those years, with annual fuel costs of $2,600 to $4,700 at 15,000 miles.

Fuel economy by year

How it compares

Against the average large cars in this dataset (about 29 MPG), the CT6 sits roughly 7 MPG below that mark on average, making it a thirstier-than-average choice for its class.

Five-year fuel cost

Fuelling a CT6 for five years at the EPA's 15,000-mile basis costs roughly $13,000 to $23,500, averaging about $18,250 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 CT6 varies by about 11 MPG between its most and least frugal versions, which run on gasoline and plug-in hybrid. Engine size, turbocharging, drivetrain and even wheel size explain most of that gap, so when you shop a used CT6 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 CT6's average combined economy slipped from about 23 to 19 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 2017 CT6 has the strongest average combined economy in this database at about 23 MPG, while the 2020 is the lowest at about 19 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 CT6 at a glance

Use the comparison tool to set the CT6 against a rival, or go back to all Cadillac models.