The GMC Terrain does 23.3 mpg combined (20.7 city, 26.6 highway), which works out to about $1,648 a year in fuel at $3.20 a gallon and 12,000 miles. Engine choice matters more than you'd think: 1.6L 4-cyl does 32 mpg while 6.2L 8-cyl does 16 — a difference of $1,200 a year. Against other 4-cyl cars it sits below the average of 25.7 mpg.
Every GMC Terrain engine, compared
Gas mileage on the GMC Terrain ranges from 32 down to 16 depending on which engine sits under the bonnet — a spread of $1,200 a year across 7 versions of the same car. Picking the right one often saves more fuel than picking a different car altogether. Yearly cost assumes 12,000 miles at $3.20 a gallon.
| Engine | Combined | City / Highway | Years | Fuel per year |
|---|---|---|---|---|
| 1.6L 4-cyl | 28 / 38 | 2018–2019 | $1,200 | |
| 1.5L 4-cyl | 25.1 / 28.9 | 2020–2027 | $1,444 | |
| 2.4L 4-cyl | 21.9 / 31.1 | 2010–2017 | $1,483 | |
| 3L 6-cyl | 19.4 / 23.6 | 2010–2026 | $1,794 | |
| 3.6L 6-cyl | 16.8 / 23.8 | 2013–2017 | $1,939 | |
| 5.3L 8-cyl | 15 / 19 | 2023–2026 | $2,259 | |
| 6.2L 8-cyl | 14 / 18 | 2022–2022 | $2,400 |
What that actually costs
The GMC Terrain burns a gallon every 23.3 miles, so 12,000 miles takes about 515 gallons a year. At $3.20 that is what the table below adds up to.
| Measure | Value |
|---|---|
| Cost per mile | $0.137 |
| Fuel per year | $1,648 |
| Fuel over five years | $8,240 |
| Against other 4-cyl cars | +$154 a year |
| EPA's own estimate | $2,914 a year |
City or highway — who is this car for
The GMC Terrain gives up 5.9 mpg the moment you leave the motorway — 26.6 out there against 20.7 in town, a 29% drop worth $411 a year. A wide gap punishes stop-and-start traffic; a narrow one means the car doesn't care where you drive it.
| Measure | Value | Reading |
|---|---|---|
| City | 20.7 mpg | $1,855 a year if you only drive in town |
| Highway | 26.6 mpg | $1,444 a year if you mostly commute |
| Gap | +5.9 mpg (29%) | Typical for its type |
How the Terrain changed over the years
The Terrain peaked in 2019 at 32 mpg (28 city, 38 highway) and was at its thirstiest in 2022 at 21.3 — 10.7 mpg apart, or $603 a year in fuel between buying one year and the other. The 2027 car does 26. Jumps usually mark a new generation or a new engine; dips often mean a heavier body or added all-wheel drive.
| Model year | Combined | City / Highway | Engines offered | Fuel per year |
|---|---|---|---|---|
| 2027 | 25 / 28 | 1 | $1,477 | |
| 2026 | 20.7 / 23.7 | 3 | $1,722 | |
| 2025 | 20.7 / 23.7 | 3 | $1,722 | |
| 2024 | 20 / 23.7 | 3 | $1,770 | |
| 2023 | 20 / 23.3 | 3 | $1,770 | |
| 2022 | 19.7 / 23.7 | 3 | $1,803 | |
| 2021 | 25 / 30 | 1 | $1,422 | |
| 2020 | 26 / 30 | 1 | $1,422 | |
| 2019 | 28 / 38 | 1 | $1,200 | |
| 2018 | 28 / 38 | 1 | $1,200 | |
| 2017 | 19 / 27.5 | 2 | $1,707 | |
| 2016 | 19.5 / 27.5 | 2 | $1,670 | |
| 2015 | 19 / 27 | 2 | $1,707 | |
| 2014 | 19.5 / 27.5 | 2 | $1,670 | |
| 2013 | 19.5 / 27.5 | 2 | $1,670 | |
| 2012 | 19.5 / 27.5 | 2 | $1,670 | |
| 2011 | 19.5 / 27.5 | 2 | $1,670 | |
| 2010 | 19.5 / 28 | 2 | $1,670 |
MPG is a number. Dollars per year is the answer.
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How we count
This page rests on 36 EPA ratings of the GMC Terrain — 7 engines across 2010–2027. The mileage is EPA's laboratory figure, unchanged; the yearly bill is ours, at 12,000 miles and $3.20 a gallon, against EPA's own estimate of $2,914. Full method.
Frequently asked questions
What mpg does the GMC Terrain get?
23.3 mpg combined on average — 20.7 in the city and 26.6 on the highway, per EPA ratings across 2010–2027.
How much does a GMC Terrain cost in fuel per year?
About $1,648 at 12,000 miles and $3.20 a gallon — roughly $8,240 over five years, or 0.137 dollars a mile.
Which Terrain engine is the most economical?
The 1.6L 4-cyl at 32 mpg, against 16 for the 6.2L 8-cyl — a difference of about $1,200 a year.
Is the Terrain good on fuel compared with similar cars?
Against other 4-cyl cars it sits below the average of 25.7 mpg, computed across 4765 ratings.
Are these real-world Terrain figures?
No — they are EPA laboratory ratings, the same ones printed on the window sticker, and EPA's own annual fuel estimate for the GMC Terrain is $2,914 against the $1,648 we compute at 12,000 miles. Expect a little worse in practice: the spread between the 32 and 16 mpg versions of this car is smaller than the spread between two drivers of the same one.
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