GMC Terrain vs Mercedes-Benz GLA-Class: Specs Compared

Also searched as Mercedes-Benz GLA-Class vs GMC Terrain specs — both orientations show this same side-by-side comparison.

The GMC Terrain is the more efficient of the two: it reaches 32 mpg combined versus 29 mpg for the Mercedes-Benz GLA-Class, a 3 mpg advantage and costs about $400 less per year to fuel.

Across 5 measured categories, the GMC Terrain leads in 4. Figures are EPA test data, not manufacturer claims.

2015–2027

GMC Terrain

Small Sport Utility Vehicle 2WD · 47 configurations

32mpg combined (best)
All GMC Terrain specs

2015–2026

Mercedes-Benz GLA-Class

Small Sport Utility Vehicle 4WD · 43 configurations

29mpg combined (best)
All Mercedes-Benz GLA-Class specs

Head-to-head specifications

MetricGMC TerrainMercedes-Benz GLA-Class
Best combined MPG32 mpg ✓29 mpg
Best city MPG28 mpg ✓26 mpg
Best highway MPG39 mpg ✓34 mpg
Lowest annual fuel costEPA estimate at 15,000 miles per year$2,200 ✓$2,600
Lowest CO2 output316 g/mi306 g/mi ✓
Engines offeredSIDI, 1.6, SIDI; FFVSIDI; Mild Hybrid, SIDI, SIDI; FFV
TransmissionsAutomatic 8-spd, Automatic (variable gear ratios), Automatic 9-spdAutomatic (AM8), Automatic (AM7)
DrivetrainsAll-Wheel Drive, Front-Wheel DriveAll-Wheel Drive, Front-Wheel Drive, 4-Wheel Drive
Fuel typesRegular, Premium, DieselPremium, Premium or E85
EPA classSmall Sport Utility Vehicle 2WDSmall Sport Utility Vehicle 4WD
Years covered2015–20272015–2026
Configurations on record4743

Source: EPA fuel economy records via fueleconomy.gov. Best-case values across all recorded configurations for each model.

GMC Terrain vs Mercedes-Benz GLA-Class dimensions and size

The GMC Terrain is 6.7 inches longer than the Mercedes-Benz GLA-Class on a wheelbase 0.4 inches shorter, and 271.2 lbs lighter. Both clear the roughly 200 inches of usable length in a standard single garage bay.

GMC Terrain versus Mercedes-Benz GLA-Class exterior dimensions
DimensionGMC Terrain (2026)Mercedes-Benz GLA-Class (2026)Difference
Length181.1 in174.4 in6.7 in
Width (excl. mirrors)74.4 in72 in2.4 in
Height65.7 in62.6 in3.1 in
Wheelbase107.1 in107.5 in0.4 in
Curb weight3,598 lbs3,869 lbs271 lbs

Width excludes mirrors; add 8–12 inches for mirrors out. Figures are for the newest model year on record for each vehicle. See both drawn to scale.

GMC Terrain vs Mercedes-Benz GLA-Class: what the numbers mean

Running cost over five years: at the EPA's 15,000-mile-a-year assumption the GMC Terrain burns about $2,200 of fuel annually against $2,600 for the Mercedes-Benz GLA-Class. That $400 yearly gap compounds to roughly $2,000 over five years and $3,200 over eight — often more than the price difference between two trims of the same vehicle, and the single largest running-cost line item separating these two.

City and highway economy: the GMC Terrain leads in both cycles — 28 mpg city and 39 mpg highway against 26 and 34 mpg — so its fuel-efficiency advantage holds whether you commute in traffic or cover long highway miles.

Powertrain choice: the GMC Terrain is recorded with 3 distinct engine configurations (SIDI, 1.6, SIDI; FFV), the Mercedes-Benz GLA-Class with 3 (SIDI; Mild Hybrid, SIDI, SIDI; FFV). Across 47 recorded GMC Terrain configurations and 43 for the Mercedes-Benz GLA-Class, the wider the engine spread the more the real-world fuel efficiency depends on which version you actually buy, so check the specific model year and drivetrain rather than the headline number.

Drivetrain and class: the GMC Terrain is offered with All-Wheel Drive, Front-Wheel Drive, the Mercedes-Benz GLA-Class with All-Wheel Drive, Front-Wheel Drive, 4-Wheel Drive. All-wheel drive typically costs one to two mpg combined against the same vehicle in front- or rear-wheel drive, which is worth remembering when the gap between these two is small. The EPA classes them as Small Sport Utility Vehicle 2WD and Small Sport Utility Vehicle 4WD respectively — the class drives the interior volume, cargo space and passenger space each one is measured against.

Tailpipe emissions: at their cleanest configurations the Mercedes-Benz GLA-Class emits 306 g/mile of CO2 versus 316 g/mile for the GMC Terrain. Emissions track fuel consumption almost exactly, so the cleaner vehicle here is also the cheaper one to fuel.

Terrain vs GLA-Class: common questions

Which is better on gas, the GMC Terrain or the Mercedes-Benz GLA-Class?

The GMC Terrain is the more efficient of the two: it reaches 32 mpg combined versus 29 mpg for the Mercedes-Benz GLA-Class, a 3 mpg advantage and costs about $400 less per year to fuel.

Which costs less to run per year?

By EPA estimates at 15,000 miles a year, the GMC Terrain runs about $2,200 a year in fuel at its most efficient configuration, versus about $2,600 for the Mercedes-Benz GLA-Class — a difference of roughly $400 per year.

What engines do the Terrain and GLA-Class offer?

GMC Terrain: SIDI, 1.6, SIDI; FFV. Mercedes-Benz GLA-Class: SIDI; Mild Hybrid, SIDI, SIDI; FFV.

Are they in the same vehicle class?

The EPA classifies the GMC Terrain as Small Sport Utility Vehicle 2WD and the Mercedes-Benz GLA-Class as Small Sport Utility Vehicle 4WD, so they aren't a like-for-like match on size.

More Terrain comparisons

More GLA-Class comparisons

Comparison id: gmc-terrain-vs-mercedes-benz-gla-class