The 2018 GMC Terrain has a fuel tank capacity of 14.9 to 15.6 gallons (56–59 liters), depending on the trim. The most common size is 14.9 gallons, used on 6 trims.
A full tank is good for roughly 406–593 highway miles or 328–437 miles around town, going by the EPA ratings.
020 gal40 gal
15.6 gal · Smaller than 73% of 2018 models we list.
Denali 4dr SUV AWD2.0L 4cyl Turbo 9A · AWD · Premium (recommended)MPG 21 / 26Range 328 / 406 mi
2.0L 4cyl Turbo 9A
AWD
15.6 gal59 L
Premiumrecommended
21 / 26
328 / 406 mi
SLE 4dr SUV AWD1.5L 4cyl Turbo 9A · AWD · RegularMPG 24 / 28Range 374 / 437 mi
1.5L 4cyl Turbo 9A
AWD
15.6 gal59 L
Regular
24 / 28
374 / 437 mi
SLE 4dr SUV AWD1.6L 4cyl Turbodiesel 6A · AWD · Diesel DieselMPG 28 / 38Range 437 / 593 mi
1.6L 4cyl Turbodiesel 6A Diesel
AWD
15.6 gal59 L
Diesel
28 / 38
437 / 593 mi
SLT 4dr SUV AWD1.5L 4cyl Turbo 9A · AWD · RegularMPG 24 / 28Range 374 / 437 mi
1.5L 4cyl Turbo 9A
AWD
15.6 gal59 L
Regular
24 / 28
374 / 437 mi
SLT 4dr SUV AWD1.6L 4cyl Turbodiesel 6A · AWD · Diesel DieselMPG 28 / 38Range 437 / 593 mi
1.6L 4cyl Turbodiesel 6A Diesel
AWD
15.6 gal59 L
Diesel
28 / 38
437 / 593 mi
No trim matches all of these filters.
Tank figures are the manufacturer's rated capacity, sorted smallest tank first. Range is tank size times EPA city or highway MPG.
How far a 2018 GMC Terrain goes on a tank
Gallons left and the distance they cover at each mark on the fuel gauge, at EPA city and highway mileage. At the combined rating of 28 MPG, a full 14.9-gallon tank covers about 417 miles.
Gauge
Gallons
Highway miles
City miles
Full
14.9
447
387
3/4
11.2
335
291
1/2
7.5
224
194
1/4
3.7
112
97
1/8
1.9
56
48
Over 15,000 miles a year (the EPA's yearly estimate) this configuration uses about 536 gallons, roughly 36 full tanks.
In real driving: owners who log fill-ups at fueleconomy.gov average 36.5 MPG in the Terrain (7 drivers), about 544 miles on a full 14.9-gallon tank.
Fuel gauges aren't perfectly linear and the low-fuel light comes on with a few gallons still in the tank, so plan your stop before the last eighth.
At 15.6 gallons, the Terrain's largest tank ranks fourth of the seven 2018 SUVs compared here. The Toyota RAV4 carries the most (15.9 gal) and the Nissan Rogue the least (14.5 gal).
Other 2018 SUVs of a similar size, one model per brand.
2018 GMC Terrain fuel system recalls
NHTSA lists 1 fuel-system recall for the 2018 GMC Terrain, out of 5 recalls in total. A recall applies only to the vehicles named in it, so check your VIN.
General Motors LLC (GM) is recalling certain 2015-2018 GMC Canyon, 2016-2017 Buick Envision, 2016-2018 Chevrolet Colorado and Malibu, 2017-2018 GMC Acadia, 2018 Buick LaCrosse, Cadillac ATS, Chevrolet Equinox, and GMC Terrain vehicles. The high pressure fuel pump may detach from its mounting flange, possibly resulting in the pump damaging the high pressure fuel line.
Risk and remedy
Risk: A damaged fuel line can create a fuel leak, increasing the risk of a fire.
Remedy: GM will notify owners, and dealers will replace the high pressure fuel pump, and high pressure fuel pipe, free of charge. The recall began July 2, 2018. Owners may contact Buick customer service at 1-800-521-7300, Cadillac customer service at 1-800-458-8006, Chevrolet customer service at 1-800-222-1020, or GMC customer service at 1-800-462-8782. GM's number for this recall is 18188.
What is the fuel tank capacity of the 2018 GMC Terrain?
The 2018 GMC Terrain holds between 14.9 and 15.6 gallons, depending on the trim. 14.9 gallons is the usual size; the 15.6-gallon tank comes on the Denali 4dr SUV AWD (2.0L 4cyl Turbo 9A).
How many gallons and liters does the 2018 GMC Terrain gas tank hold?
The 2018 GMC Terrain tank holds 56–59 liters, or 14.9–15.6 gallons in US gallons.
Which 2018 GMC Terrain has the biggest gas tank?
The 15.6-gallon tank is on the Denali 4dr SUV AWD, SLE 4dr SUV AWD, SLE 4dr SUV AWD and 2 other trims. The smallest tank, 14.9 gallons, is on the Denali 4dr SUV.
Does the 2018 GMC Terrain tank change with the powertrain?
No. Gas and Diesel versions of the 2018 GMC Terrain use the same 14.9–15.6 gal tank.
Does AWD change the 2018 GMC Terrain gas tank?
Yes. FWD: 14.9 gal; AWD: 15.6 gal.
How far can a 2018 GMC Terrain go on a full tank?
About 406–593 miles on the highway and 328–437 miles in town, going from full to empty at its EPA ratings. Expect less in practice, since nobody runs the tank dry.
How many miles can a 2018 GMC Terrain go on a quarter tank?
About 112 highway miles or 97 in town from the 14.9-gallon tank, which has roughly 3.7 gallons left at the quarter mark. Gauges aren't exact, so treat that as a guide.
How many miles does a 2018 GMC Terrain really get on a tank?
Drivers who log their fill-ups at fueleconomy.gov average 36.5 MPG in the 2018 GMC Terrain (7 drivers), which works out to about 544 miles on a full 14.9-gallon tank.
What gas does the 2018 GMC Terrain take?
Regular unleaded, or Diesel fuel, or Premium unleaded (recommended), depending on the engine. The label inside the fuel door confirms it for your car.
How much does it cost to fill up a 2018 GMC Terrain?
At the US average of $4.27 a gallon for regular (EIA, week of October 26, 2026), filling the 14.9-gallon tank from empty costs $63.62. It ranges from $55.13 in the Gulf Coast to $87.76 in California.
How much does a full tank of gas weigh in a 2018 GMC Terrain?
About 109 pounds for the 15.6-gallon tank. Diesel weighs roughly 7 pounds a gallon.
Does the 2018 GMC Terrain have a bigger gas tank than the Jeep Cherokee?
No. The 2018 Jeep Cherokee holds up to 15.8 gallons; the 2018 GMC Terrain holds up to 15.6.
Has the 2018 GMC Terrain had a fuel pump or fuel system recall?
Yes. NHTSA lists 1 fuel-system recall for the 2018 GMC Terrain: 18V358000 (delivery · fuel pump). Check your VIN at nhtsa.gov/recalls to see if your car is affected.
Sources
Tank sizes: manufacturer-rated capacities from US-market specifications, checked against independent references. Updated October 2026.
MPG and range: EPA ratings (fueleconomy.gov). Range is tank size times EPA MPG.
Fuel prices: U.S. Energy Information Administration, week of October 26, 2026 (this week's prices).