GMC Terrain Gas Type: What Fuel Your SUV Really Needs

Ever stared at the gas pump wondering what to put in your GMC Terrain? You’re about to save yourself potential headaches and maybe even some cash. The right fuel choice impacts everything from your engine’s performance to its longevity.

Which Gas Type Does the GMC Terrain Use?

Most GMC Terrain models run on regular unleaded gasoline with an 87 octane rating. This applies to the current 1.5L turbocharged engines (2018-present) and older 2.4L and 3.6L engines (2010-2017). However, the 2.0L turbocharged engine (2018-2023) performs best with premium 93-octane gasoline, though it can run on regular 87-octane with slightly reduced power.

If you have the rare 1.6L turbo-diesel model (2018-2020), you’ll need ultra-low sulfur diesel (ULSD) with ≤15 ppm sulfur content.

Fuel Requirements by GMC Terrain Engine Type

Here’s a quick reference guide to match your engine with its ideal fuel:

Can I Use Premium Gas in My GMC Terrain?

You can use premium gas in any GMC Terrain, but it’s only beneficial for the 2.0L turbocharged engine. For all other models, including the popular 1.5L turbo, premium gas is just throwing money away.

The 2.0L turbo engine shows measurable performance differences:

• Using 87 octane: Noticeable power loss (6-8%)
• Using 93 octane: Optimal torque and acceleration (0-60 mph times improve by about 0.7 seconds)

What About Ethanol Blends for the GMC Terrain?

Modern GMC Terrain models (2024-2025) with gasoline engines are certified for E15 (15% ethanol) blends. This aligns with EPA guidelines and won’t harm your engine.

However, there are strict limits:

• E15 (15% ethanol): Safe for all gasoline Terrain models
• E85 (85% ethanol): Only compatible with specific flex-fuel first-generation models (mainly 2011-2014 with the 3.6L V6)

Using E85 in a non-flex-fuel Terrain can cause serious corrosion to fuel lines and injectors.

Fuel Efficiency and Tank Size

Understanding your Terrain’s fuel capacity helps with trip planning:

The current 1.5L turbo engine achieves approximately 24 MPG city and 29 MPG highway in front-wheel-drive configuration. The discontinued diesel option offered impressive efficiency with 28 MPG city and 38 MPG highway.

What Happens If You Use the Wrong Fuel?

Using incorrect fuel in your GMC Terrain can have significant consequences:

1. Regular instead of premium in 2.0L turbo models: Reduced power (6-8% less), slightly worse fuel economy (2-3%), but no engine damage
2. Premium instead of regular in other models: No benefit, just wasted money
3. E85 in non-flex-fuel models: Potential damage to fuel system components, reduced performance, possible check engine lights
4. Gasoline in diesel models: Severe engine damage requiring expensive repairs—never mix these up!

Has the GMC Terrain Gas Type Changed Over Time?

Yes, GMC has evolved the Terrain’s fuel requirements across generations:

• First Generation (2010-2017): Primarily regular 87 octane for both 2.4L I4 and 3.6L V6 engines. Some V6 models offered flex-fuel capability.
• Second Generation (2018-Present): Introduced turbocharged engines with more specific fuel requirements. The 2.0L turbo recommends premium, while the standard 1.5L turbo uses regular gas. The diesel option required ULSD.
• Recent Updates (2024-2025): The lineup has been streamlined to focus on the 1.5L turbo engine, with E15 compatibility added. Both the 2.0L gas and 1.6L diesel options have been discontinued.

Direct Injection and Fuel System Considerations

When GMC redesigned the Terrain in 2018, they implemented direct injection technology across the engine lineup. This improved fuel efficiency but introduced a potential maintenance concern: carbon buildup on intake valves.

Regular-grade gas works perfectly fine, but consider these maintenance tips:

• Use Top Tier™ certified gasoline when possible (available at major brands like Shell, Chevron, Exxon)
• Follow the manufacturer’s maintenance schedule
• Consider periodic intake valve cleaning service (around 60,000-80,000 miles)

GMC Terrain Diesel Fuel Requirements

If you’re one of the few with the 1.6L turbo-diesel Terrain (2018-2020), your fuel needs are different:

• Required Fuel: Ultra-low sulfur diesel (ULSD) with no more than 15 ppm sulfur content
• DEF Requirement: Diesel exhaust fluid needs replenishing approximately every 10,000-12,000 miles
• Consumption Rate: About 1 gallon of DEF per 1,000 miles driven

The diesel Terrain achieved impressive efficiency with EPA ratings of 28 MPG city and 38 MPG highway. Real-world testing often showed 34 MPG combined, making it excellent for long-distance driving.

What Gas Do Different GMC Terrain Trims Take?

The fuel requirement isn’t determined by the trim level (SLE, SLT, AT4, Denali) but by the engine type. However, higher trims were more likely to come with the 2.0L turbo engine that benefits from premium fuel.

For current models (2024-2025):

• All trims come with the 1.5L turbo engine that uses regular 87 octane gas
• E15 (15% ethanol) is compatible with all trims
• Premium fuel provides no benefit regardless of trim level

Tips for Optimal Fuel Economy in Your GMC Terrain

Maximize your Terrain’s efficiency with these practical tips:

1. Maintain proper tire pressure – check monthly as pressure affects fuel economy by up to 3%
2. Replace air filters regularly – a clogged filter can reduce efficiency by up to 10%
3. Use the stop/start technology – this feature, standard since 2018, reduces idle fuel consumption by 3-5% in city driving
4. Lighten your load – removing unnecessary weight improves efficiency (every 100 pounds reduces MPG by about 1%)
5. Plan trips efficiently – combining errands and avoiding rush hour traffic helps maximize fuel economy

Should You Use Additives in Your GMC Terrain?

Fuel additives are rarely necessary for the GMC Terrain if you’re using quality gasoline. However, they might help in specific situations:

• If you’re storing your vehicle for an extended period (fuel stabilizer)
• If you notice rough idling or hesitation (fuel system cleaner)
• If you frequently fill up at low-quality gas stations (occasional injector cleaner)

For regular driving, the detergents in Top Tier™ gasoline provide sufficient cleaning without additional additives.

Real-World Data on GMC Terrain Fuel Consumption

According to owner reports and testing, here’s what you can expect in real-world driving:

• 1.5L Turbo FWD: 22-24 MPG city, 27-29 MPG highway
• 1.5L Turbo AWD: 20-22 MPG city, 25-27 MPG highway
• 2.0L Turbo AWD: 19-21 MPG city, 25-26 MPG highway
• 1.6L Diesel AWD: 26-28 MPG city, 34-38 MPG highway

These figures vary based on driving conditions, climate, and individual driving habits. The EPA’s official fuel economy ratings provide a good baseline, but most owners report slightly lower real-world figures.

The Bottom Line on GMC Terrain Fuel Requirements

For most GMC Terrain owners, the choice is simple: use regular 87 octane gasoline. The only exceptions are:

1. If you have a 2.0L turbocharged engine (2018-2023) and want maximum performance, use premium 93 octane gas
2. If you have a diesel model, always use ultra-low sulfur diesel and maintain your DEF levels

Remember that while E15 (15% ethanol) is safe for all gasoline models, higher ethanol blends like E85 should only be used in designated flex-fuel vehicles.

By following these guidelines, you’ll keep your GMC Terrain running smoothly while avoiding unnecessary expense at the pump.