2018 GMC Terrain — Full Specifications
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The 2018 GMC Terrain is an SUV offered with 3 engines (1.5L 4-cyl turbo, 1.6L 4-cyl turbo, 2L 4-cyl turbo). Its most fuel-efficient configuration returns around 38 mpg (UK) / 32 mpg (US EPA) combined, with 28–38 mpg (UK) across all configurations. Owners often keep a GMC Terrain workshop manual to hand for servicing and repairs.
Compared with the 2017 GMC Terrain: Fuel economy improves from 30 to 38 mpg (UK) combined on the most efficient configuration. EPA lists new engine options for 2018: 1.5L 4-cyl turbo, 1.6L 4-cyl turbo, 2L 4-cyl turbo. No longer listed: 2.4L 4-cyl, 3.6L 6-cyl. The overall NHTSA rating moves from 4★ to 5★. EPA passenger volume changes from 100 to 104 cu ft.
Full Specifications
| Engine (most efficient) | 1.6L 4-cyl turbo |
|---|---|
| Engine options | 1.5L 4-cyl turbo · 1.6L 4-cyl turbo · 2L 4-cyl turbo |
| Transmission (most efficient) | Automatic 6-spd |
| Fuel Type | Diesel |
| Powertrain | Conventional |
| Drive | All-Wheel Drive |
| Body Style | SUV |
| Length | 4707 mm |
| Height | 1684 mm |
| Passenger Volume (EPA) | 104 cu ft (2,945 L) |
| Luggage Volume (EPA) | 30 cu ft (850 L) |
| Fuel Economy (UK) | 38 combined / 34 urban / 46 extra-urban mpg |
| Fuel Economy (US EPA) | 32 combined / 28 city / 38 highway mpg |
| CO₂ Emissions | 198 g/km |
| EPA Greenhouse Gas Score | 5 / 10 (10 = lowest emissions) |
| EPA Est. Annual Fuel Cost | $3,000 (15,000 mi/yr, US prices) |
Engine & Transmission Options
EPA lists 6 configurations for the 2018 GMC Terrain across 3 engines (1.5L 4-cyl turbo, 1.6L 4-cyl turbo, 2L 4-cyl turbo). Combined fuel economy ranges from 23 to 32 mpg (US), or 28 to 38 mpg (UK), depending on engine, transmission and drive. The headline figures at the top of this page describe the most fuel-efficient configuration.
| Engine | Transmission | Drive | MPG (UK) | MPG (US) | CO₂ g/km | Fuel cost / yr |
|---|---|---|---|---|---|---|
| 1.5L 4-cyl turbo | Automatic 9-spd | All-Wheel Drive | 31 | 26 (24/28) | 211 | $2,600 |
| 1.5L 4-cyl turbo | Automatic 9-spd | Front-Wheel Drive | 34 | 28 (26/30) | 196 | $2,400 |
| 1.6L 4-cyl turbo | Automatic 6-spd | All-Wheel Drive | 38 | 32 (28/38) | 198 | $3,000 |
| 1.6L 4-cyl turbo | Automatic 6-spd | Front-Wheel Drive | 38 | 32 (28/39) | 198 | $3,000 |
| 2L 4-cyl turbo | Automatic 9-spd | All-Wheel Drive | 28 | 23 (21/26) | 240 | $3,550 |
| 2L 4-cyl turbo | Automatic 9-spd | Front-Wheel Drive | 29 | 24 (22/28) | 229 | $3,400 |
MPG (US) shows combined, with city/highway in brackets. Highlighted row = the configuration used for the headline figures. Source: US EPA fueleconomy.gov.
EPA measures interior passenger volume at 104 cubic feet (about 2,945 litres) and luggage volume at 30 cubic feet (about 850 litres). These are US EPA interior-volume figures; they are measured differently from the boot capacity numbers UK manufacturers quote.
Owner Essentials for the 2018 GMC Terrain
Running Costs: 2018 GMC Terrain
Covering around 8,000 miles a year in a 2018 GMC Terrain at 38 mpg combined, expect roughly 957 litres of fuel annually — multiply by your local price per litre for a cost estimate. For US owners, the EPA estimates about $3,000 a year in fuel for the most efficient configuration (15,000 miles, national average prices). Work out exact fuel costs with the fuel cost calculator on 247Calculators.
Convert between MPG and L/100km with the unit converters on 247QuickTools. Not sure what tyre size fits? 247TyreCheck explains tyre sizing.
Planning a road trip? Grab a road trip packing list. Only need this car occasionally? See our buy vs rent comparison.
2018 GMC Terrain Safety Ratings (NHTSA)
Recalls & Owner Complaints (NHTSA)
NHTSA lists 5 safety recall campaigns that include the 2018 GMC Terrain (as of 6 October 2026). Most affected areas: Power train (2), Service brakes (1), Fuel system (1). A campaign often covers several model years or models, so check your own VIN to see whether your car is affected.
- Power train — campaign 20V668000, reported 29 October 2020. Risk: Missing bolts on the start-stop accumulator endcap could result in a transmission oil leak and may progress to a loss of propulsion, increasing the risk of a crash. A transmission fluid leak in the presence of…
- Service brakes — campaign 18V576000, reported 30 August 2018. Risk: A reduction of braking performance can increase the risk of a crash.
- Fuel system — campaign 18V358000, reported 31 May 2018. Risk: A damaged fuel line can create a fuel leak, increasing the risk of a fire.
- Air bags — campaign 18V340000, reported 24 May 2018. Risk: If the SDM becomes inoperative, it will not detect a crash or command the necessary air bag deployment, increasing the risk of injury in the event of a crash.
Showing the 4 most recent of 5 campaigns.
Owners have filed 223 complaints with NHTSA about the 2018 GMC Terrain. The most-reported areas are Service brakes (69), Engine (54), Power train (41). Complaints include 14 reported crashes, 1 reported fire, 12 reported injuries. That is close to the median of 185 complaints across the 17 GMC Terrain model years in our data.
Used-buyer checklist for the 2018 GMC Terrain
Based on where NHTSA recalls and owner complaints cluster for this model year, these are the areas worth checking before you buy:
- Brakes (1 recall campaign · 69 owner complaints) — Brake firmly from speed and look for pulling, vibration or a soft pedal; ask for brake service history.
- Transmission & drivetrain (2 recall campaigns · 41 owner complaints) — On the test drive, watch for hesitation, jerking or slipping between gears and ask for transmission service history.
- Engine (54 owner complaints) — Listen for unusual noise on a cold start, check for warning lights and ask for the service records.
- Fuel system (1 recall campaign) — Ask whether any fuel-pump or fuel-system recalls were completed, and watch for hard starting or stalling.
Source: US NHTSA recall and consumer-complaint databases, retrieved 6 October 2026. Complaints are unverified owner reports, not confirmed defects. Check any vehicle by VIN at nhtsa.gov/recalls, and see our guide to checking a used car for recalls.
How It Compares
How does the GMC Terrain compare to similar SUVs? For context, SUVs in our database average around 27 mpg (UK) combined — this model's 38 mpg figure is 11 mpg better than that average. Its 198 g/km CO₂ figure is 55 g/km lower than the 253 g/km average for SUVs on this site. This comparison is based on 1824 SUVs in our dataset.
GMC models in our database average about 26 mpg (UK) combined on their most efficient configuration; the 2018 GMC Terrain's 38 mpg is 12 mpg above that make average. Its 198 g/km CO₂ figure is 74 g/km lower than the 272 g/km GMC average.
Of the 17 GMC Terrain model years we cover, the 2018 is the most economical on its best configuration (38 mpg UK combined). See every GMC Terrain year side by side.
Last updated: · Data: US EPA (fueleconomy.gov) and NHTSA safety ratings 18 July 2026; NHTSA recalls and complaints 6 October 2026; Wikidata & curated EU catalogue 18 July 2026; European generation and engine data from Wikipedia 7 October 2026
Vehicle data sourced from manufacturer specifications. Always verify with your vehicle handbook or a qualified mechanic. This is a reference tool, not professional advice.
Recommended Accessories for the 2018 GMC Terrain
Frequently Asked Questions
What engine does the 2018 GMC Terrain have?
EPA lists 3 engines for the 2018 GMC Terrain: 1.5L 4-cyl turbo, 1.6L 4-cyl turbo, 2L 4-cyl turbo. The most fuel-efficient configuration pairs the 1.6L 4-cyl turbo with a automatic 6-spd.
What is the fuel economy of the 2018 GMC Terrain?
The most efficient configuration returns around 38 mpg (UK) combined, or 32 mpg on the US EPA cycle. Across all configurations the UK combined figure runs from 28 to 38 mpg.
How much does the 2018 GMC Terrain cost to fuel per year?
The US EPA estimates about $3,000 a year in fuel for the most efficient configuration, based on 15,000 miles of mixed driving and national average fuel prices. Your own cost will depend on mileage and local prices.
Does the 2018 GMC Terrain have a good safety rating?
It holds an overall NHTSA rating of 5 stars, with 5 stars for frontal crash protection.
Does the 2018 GMC Terrain have any recalls?
NHTSA lists 5 safety recall campaigns that include the 2018 GMC Terrain (as of 6 October 2026). Most affected areas: Power train (2), Service brakes (1), Fuel system (1). A campaign often covers several model years or models, so check your own VIN to see whether your car is affected.
What are the most common problems reported for the 2018 GMC Terrain?
Among the 223 owner complaints filed with NHTSA, the most-reported areas are Service brakes (69 complaints), Engine (54 complaints), Power train (41 complaints). Complaints are unverified owner reports, not confirmed defects, and raw counts rise with how many cars were sold.
How much interior and luggage space does the 2018 GMC Terrain have?
EPA measures interior passenger volume at 104 cubic feet (about 2,945 litres) and luggage volume at 30 cubic feet (about 850 litres). These are US EPA interior-volume figures, which are measured differently from the UK boot-capacity numbers manufacturers quote.
Is the GMC Terrain's fuel economy good for an SUV?
Yes — it returns around 38 mpg (UK) combined, against a same-body-style average of roughly 27 mpg among the SUVs we track, making it one of the more efficient options in its class.