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EPA ratings · 2018 · GMC · Terrain

2018 GMC Terrain Fuel Economy

EPA rates the 2018 GMC Terrain's 6 trims from 23 to 32 MPG combined, Terrain AWD to Terrain AWD. The table below prices every trim per mile at a fuel price and mileage you can change.

EPA ratings by trim

2018 GMC Terrain trims and EPA ratings
TrimEngineTransmissionDriveCityHwyCombined
Terrain AWD · Premium2 L, 4 cylAutomatic 9-spdAll-Wheel Drive212623 MPG
Terrain AWD · Regular1.5 L, 4 cylAutomatic 9-spdAll-Wheel Drive242826 MPG
Terrain AWD · Diesel1.6 L, 4 cylAutomatic 6-spdAll-Wheel Drive283832 MPG
Terrain FWD · Premium2 L, 4 cylAutomatic 9-spdFront-Wheel Drive222824 MPG
Terrain FWD · Regular1.5 L, 4 cylAutomatic 9-spdFront-Wheel Drive263028 MPG
Terrain FWD · Diesel1.6 L, 4 cylAutomatic 6-spdFront-Wheel Drive283932 MPG

City and highway are EPA's adjusted label figures; combined is the 55/45 blend printed on the window sticker. For electric and plug-in trims the MPG columns are MPGe, and the kWh per 100 miles is the figure a charging cost actually turns on; EPA measures it at the wall, so charging losses are already in it. Unrounded combined figures, where EPA publishes them: Terrain AWD 23; Terrain AWD 25.9965; Terrain AWD 31.8173; Terrain FWD 24; Terrain FWD 27.6853; Terrain FWD 31.7819.

What the rating costs per mile

The rating divided by a price, times your miles. It starts at EIA's current U.S. averages and EPA's 15,000 miles so the right-hand column is comparable; type your own pump price, home rate and mileage over them.

Fuel cost per mile and per year for each trim at the prices and mileage above
TrimRuns onRatedPer milePer yearEPA's figure
Terrain AWDPremium Gasoline23 MPG18.6¢$2,794$3,550
Terrain AWDRegular Gasoline26 MPG16.5¢$2,472$2,600
Terrain AWDDiesel32 MPG13.4¢$2,008$3,000
Terrain FWDPremium Gasoline24 MPG17.8¢$2,678$3,400
Terrain FWDRegular Gasoline28 MPG15.3¢$2,295$2,400
Terrain FWDDiesel32 MPG13.4¢$2,008$3,000

Per mile = price ÷ rated MPG (gasoline) or price per kWh × kWh per 100 miles ÷ 100 (electricity). Per year = per mile × miles. EPA's figure is its own annual fuel cost at 15,000 miles, 55% city, and the national price in force when the file was built; it will differ from the middle columns whenever the price here differs. A plug-in hybrid is shown once on each fuel; its real cost sits between them, by how much of its driving is on the battery.

Fuel only — before depreciation, insurance, maintenance or tires, which the True Cost per Mile Calculator adds. Most drivers land below the rating; the True MPG Calculator measures your own from two fill-ups.

EPA's own figures, and why they differ

The “EPA's figure” column is EPA's annual fuel cost from the same file: 15,000 miles, 55% city, and the national fuel price fueleconomy.gov was using on the day the file was built (2026-09-29). fueleconomy.gov recomputes its page every week at the current price, so its number and the file's drift apart between file dates; the middle columns here use a price you can see and change, which is the only honest way to compare two cars. EPA also prints a five-year “you save/spend” against the average new vehicle (spends $3,000 for the Terrain AWD); it rests on the same assumptions and is not repeated here as a result.

Every figure on this page is a rating, not a measurement of any particular car. The site never calls a rating wrong; it shows what your own price and miles do to it. See the model on fueleconomy.gov.

Other model years of the GMC Terrain: 2027, 2026, 2025, 2024, 2023, 2022, 2021, 2020, 2019, 2017, 2016, 2015, 2014, 2013, 2012, 2011, 2010.

Related tools

Informational only — published averages for scale and comparison, not a quote for any pump, utility or vehicle. Your own price is the one that counts, and every calculator on this site takes it as an input.

Ratings: U.S. EPA and U.S. DOE, fueleconomy.gov vehicles.csv dated 2026-09-29 (EPA record ids 38691, 39091, 39315, 38686, 39267, 39313). Prices: EIA, U.S. regular gasoline week of October 19, 2026; U.S. residential electricity August 2026. Snapshots refreshed monthly.