For a crossover called the GMC Terrain, we haven’t felt much uneven terrain underneath our seats thanks to its focus on comfort in the interior, despite it subtly whispering “maximum attack” at the exterior.
But while it’s not exactly our weapon of choice for the Dakar Rally, the GMC Terrain does perform decently on asphalt and on light gravel when given gallons of its favorite fuel.
So before you even think about taking it on any terrain that isn’t as smooth as a baby’s bottom while having 50 lbs of groceries in the back, fixate your eyes on this guide on the gas types you should and shouldn’t use for the GMC Terrain!
What type of gas does a GMC Terrain use?
The GMC Terrain uses regular unleaded 87-octane gasoline for all generations and gas engine options, though premium 93-octane gasoline is recommended for the 2-liter I4 option
The GMC Terrain 1.6 diesel variant uses ultra-low sulfur diesel (ULSD) with 15 ppm of sulfur content max.
Like many other vehicles that we’ve covered in our “gas type” guides, the GMC Terrain likes to keep a pretty simple fuel requirement for its lineup of engines.
All models or “variants” of the 1st-gen GMC Terrain were basically designed to take regular 87-octane gasoline whichever engine you go for. Yes, this includes even the bigger V6s.
This fuel requirement is identical to its close GM relative, the 2nd-gen Chevy Equinox, which also shares the same engines and is built on the same “Theta” platform.
The 2nd-gen Terrain is where things start to vary a little bit in terms of the octane rating and even the type of fuel itself. General Motors decided to give the Terrain a diesel option this time around.
While all of the 2nd-gen model’s gas engines can run on regular 87-octane gas just fine, the 2-liter I4 turbo, in particular, runs the best when using premium 93-octane fuel, thus being recommended by the manufacturer.
Then, of course, the lone 1.6-liter diesel engine option should never drink a drop of gasoline or “petrol” in its life. Rather, it calls for ultra-low sulfur diesel (ULSD).
Aside from octane ratings, we’ll be diving into a bit more detail into things such as fuel blends, the use of ethanol, and even the types of fuel you shouldn’t be putting in your GMC Terrain’s gas tank further below.
GMC Terrain Fuel Requirements by Generation and Engine Option
1st-gen GMC Terrain models require unleaded gasoline with a minimum octane rating of 87 or higher for all engine options
2nd-gen GMC Terrain models require at least 87-octane gas for the 1.5-liter I4, 93-octane gas for the 2-liter I4, and ultra-low sulfur diesel for the 1.6-liter I4 diesel.
1st-Generation GMC Terrain (2010 to 2017)
| Engine Option | Minimum Fuel Requirement |
| 2.4L Ecotec LAF Inline-4 (I4) | 87-Octane Gasoline (Regular) or Higher |
| 2.4L Ecotec LEA Inline-4 (I4) | 87-Octane Gasoline (Regular) or Higher |
| 3.0L High Feature LF1/LFW V6 | 87-Octane Gasoline (Regular) or Higher |
| 3.6L High Feature LFX V6 | 87-Octane Gasoline (Regular) or Higher |
Right after the first Chevy Equinox generation ended its production in 2009, General Motors decided to make a boxier and more premium GMC equivalent in the form of the GMC Terrain, which debuted the same year as the 2nd-gen Equinox.
The 1st-gen GMC Terrain shares the same engine lineup as the 2nd-gen Equinox, which includes 4-cylinder engines such as the 2-liter “LAF” I4 in 2010 and the 2-liter “LEA” I4 in 2012.
Also available from the 2010 model year was the “High Feature” 3-liter LF1/LFW V6, which was eventually replaced by the bigger-displacement 3.6-liter “LFX” V6 starting in 2013.
Despite the differences in cylinders and power figures between the aforementioned engines, all of them have the same minimum fuel requirement of 87-octane gasoline.
It’s also worth mentioning that all of the 1st-gen GMC Terrain engines are compatible with ethanol-blended gasoline, though the exact percentage will differ depending on the model year.
2011 and older models are limited to 10% ethanol content (E-10), while 2012 and newer models have been bumped to 15% ethanol content (E-15) as per the EPA’s updated ethanol waivers.
Furthermore, certain model years of such engines are also offered with E-85/Flex-Fuel compatibility, which we delve into more in the “E-85/Flex-Fuel” section further down.
2nd-Generation GMC Terrain (2018 to 2023/Present)
| Engine Option | Minimum Fuel Requirement |
| 1.5L LYX Inline-4 (I4) Turbo | 87-Octane Gasoline (Regular) or Higher |
| 1.5L LSD Inline-4 (I4) Turbo | 87-Octane Gasoline (Regular) or Higher |
| 2.0L LTG Inline-4 (I4) Turbo | 87-Octane Gasoline (Regular) or Higher(Premium 93-Octane Recommended) |
| 1.6L LH7 Inline-4 (I4) Turbo Diesel | Ultra-Low Sulfur Diesel (Max 15 ppm) |
By the 2018 model year, General Motors completely revamped the GMC Terrain for the 2nd-generation model both in terms of design features and the lineup of engines that can be found under the hood.
For the 2nd-gen GMC Terrain, all of the previous naturally-aspirated 4-cylinder engines were binned in favor of turbocharged ones, the first being the 1.5-liter “LYX” I4.
The LYX was eventually replaced this 2023 by an updated version of the same displacement called the “LSD”, as weird as that name may sound to some people.
Despite these engines being turbocharged, both the 1.5-liter LYX and LSD I4s are made to run primarily on a minimum of 87-octane gasoline (regular) to achieve optimum performance.
Even the top-of-the-line 2-liter “LTG” I4 turbo power plant, which was only offered for the 2018 to 2020 Denali trims, can run on regular 87-octane gasoline as well.
However, as stated in the 2018 to 2020 GMC Terrain owner’s manual, it’s recommended to use premium 93-octane gasoline to get the maximum power output and the best fuel economy possible out of the 2.0 LTG.
Let’s not forget about the 1.6-liter “LH7” I4 turbo diesel option, which is just about the only diesel engine that you can get for any GMC Terrain model. It has since been discontinued and was only offered from 2018 to 2019.
For the 1.6-liter diesel model, you can’t just use any old diesel fuel. Rather, the owner’s manual specifically calls for ultra-low sulfur diesel (ULSD) with no more than 15 ppm of sulfur content.
Types of Gasoline/Fuel That Can Be Used in a GMC Terrain
The GMC Terrain can be filled up with TOP TIER detergent gasoline, reformulated gasoline, up to 10% or 15% ethanol (E-10/E-15), and E-85/Flex-Fuel (FFV models).
GMC Terrain diesel models can be filled with TOP TIER detergent diesel, ultra-low sulfur diesel (max 15 ppm), and up to 20% biodiesel (B20).
TOP TIER Detergent Gasoline
One of the most recommended types of gasoline by the majority of automakers is TOP TIER detergent gasoline, and this remains true with GMC for the Terrain crossover SUV.
As its name suggests, you’re only going to get high-quality gasoline made according to “top-tier” standards in terms of detergent additives.
Such detergent additives in TOP TIER fuel have been proven both safe and effective in cleaning your engine and fuel system by preventing the buildup of carbon deposits or debris inside them.
Thus, having a cleaner engine will help a lot in maintaining the optimum performance of your vehicle. Just remember to still use the required or recommended octane rating for your specific engine, of course.
Over 60 fuel brands in North America sell TOP TIER gasoline, and you can spot one at your local gas station by looking for its own unique label at the machine or pump.
But just in case you’re unable to find any TOP TIER fuel in your area, the manufacturer recommends using a bottle of “ACDelco Fuel System Treatment Plus – Gasoline” in the fuel that you fill up with.
The fuel system treatment should be added after every oil change or 9,000 miles added to the odometer.
Reformulated Gasoline
Another suitable fuel type for the GMC Terrain is reformulated gasoline, a relatively modern type of fuel that is mainly blended to reduce the impact of harmful emissions on the environment.
Proper reformulated gasoline, or “RFG”, contains less toxic ingredients, and when emitted, results in lesser pollutants that are known to contribute to the formation of ozone, such as NOX (nitrogen oxide) and other volatile organic compounds (VOC).
Thanks to its environmental benefits, many metropolitan areas where there is a higher concentration of air pollution actually mandate selling reformulated gasoline to help mitigate this issue.
Over 30% of the gasoline in circulation in the US is reformulated gasoline (RFG), so it’s a considerably common type of alternative fuel suitable for many gasoline-powered vehicle models.
However, RFG can be hard to distinguish from regular gasoline due to the lack of labels, which is why we recommend asking your local retailer if it’s available.
Up to 10% or 15% Ethanol Blends (E-10/E-15)
Ethanol, a type of oxygenate, has been used in gasoline to raise its octane rating, reduce emissions, and make fuel more renewable.
Many vehicles of today, including the GMC Terrain, are capable of using gasoline blended with ethanol. But how much ethanol are we talking about exactly?
Based on our research, 2011 and older GMC Terrain models are only compatible with gasoline containing up to 10% ethanol, such as “E-10” fuel.
2012 and newer GMC Terrain models, however, have been given the go signal to use up to 15% ethanol in gasoline (E-15) after the EPA updated its waivers regarding ethanol usage.
Since these models are limited to 15% ethanol at most and cannot use any higher blends such as E-85/Flex-Fuel, they only come with a regular black gas cap.
E-85/Flex-Fuel (Flex-Fuel Models Only)
Certain models of the GMC Terrain are “FFVs” (Flex-Fuel Vehicles), meaning that they are capable of using a type of ethanol blended known as E-85 or “Flex-Fuel”.
Compared to more common ethanol blends such as E-10 and E-15, E-85 can contain up to 85% ethanol with the remaining 15% being pure gasoline.
The only GMC Terrain models that are compatible with E85/Flex-Fuel are as follows:
1. 2.4L Ecotec I4 – 2012 to 2017 Models
2. 3.0L High Feature V6 – 2011 to 2012 Models
3. 3.6L High feature V6 – 2013 to 2014 Models
The summary above is based on data from fueleconomy.gov regarding the gas mileage of GMC Terrain models from 2010 to 2017.
Such GMC Terrain Flex-Fuel models will come equipped with a special yellow fuel cap to distinguish them from non-Flex-Fuel vehicles.
Ultra-Low Sulfur Diesel Fuel (Max 15 ppm) (1.6 Diesel Model Only)
Moving on to non-gasoline fuel types, ultra-low sulfur diesel (ULSD) is the go-to fuel for the GMC Terrain 1.6-liter I4 turbo diesel variant.
Ultra-low sulfur diesel is formulated to only contain a maximum of 15 ppm (parts per million) of sulfur content, which is the maximum allowed for this type of diesel ever since its initial phase-in back in 2006.
With sulfur levels as low as that of ULSD, harmful emissions of diesel fuel are kept to a minimum and better emissions control components can be installed on today’s diesel vehicles.
TOP TIER Detergent Diesel
Much like its gasoline counterpart, TOP TIER detergent diesel fuel is highly recommended by the manufacturer for use in the GMC Terrain 1.6-liter I4 turbo diesel model.
Containing the same high-quality detergent additives as the gasoline version, TOP TIER diesel applies safe and effective cleaning to your engine and fuel system to keep it free of deposits.
Just keep in mind that TOP TIER diesel fuel is a bit more tricky to find compared to TOP TIER gas, as only a few retailers in North America actually sell it.
But with that said, if you’re unable to find TOP TIER diesel but still want to feel the benefits of engine-cleaning additives, then GMC also recommends using “ACDelco Diesel Fuel Conditioner”.
Another alternative additive is “ACDelco Fuel System Treatment Plus-Diesel”, which is essentially just the diesel version of the additive we’ve already discussed earlier for the TOP TIER gasoline version.
Up to 20% Biodiesel (B20)
Continuing the trend of alternative fuel types, the GMC Terrain diesel model is also compatible with up to 20% biodiesel content, which is commonly labeled as “B20” at refueling stations.
Biodiesel is a type of biofuel that is typically made out of recycled animal fats or vegetable oil, resulting in a more renewable and cleaner-burning alternative to conventional diesel.
Be sure to not go past the 20% biodiesel limit for the GMC Terrain. If you go any higher than that, then there’s a chance that you’ll accumulate deposits in your engine and fuel system faster.
Types of Gasoline/Fuel to Avoid for the GMC Terrain
Avoid filling up the GMC Terrain with gasoline containing MMT, methanol, methylal, ferrocene, or aniline. Do not use any gasoline with a lower octane rating than 87 as well.
Gasoline Containing MMT (Methylcyclopentadienyl Manganese Tricarbonyl)
MMT has been used as an octane-boosting additive in both leaded and unleaded gasoline for decades, but it’s notorious for having negative effects that have led many fuel brands to not use it anymore.
The manufacturer does not recommend using gasoline containing MMT for the GMC Terrain, as this type of additive is known to prematurely wear out your spark plugs and damage other important components of the emissions system.
Aside from that, MMT is also quite toxic when emitted from your vehicle’s exhaust, and places that still use it in gasoline are strictly limited to only 1/32 gpg Mn (grams per gallon of Manganese).
With the kinds of environmental and health concerns that MMT has raised in the past, it’s no wonder that the majority of car manufacturers advise against adding even a single drop of it in your fuel tank.
Fuel Containing Methanol, Methylal, Ferrocene, or Aniline
There are still a few “incompatible” fuel types worth talking about that you should definitely avoid feeding your GMC Terrain SUV with, namely fuel containing methanol, methylal, ferrocene, and aniline.
According to the GMC Terrain owner’s manual, these types of materials or ingredients can cause damage to various metal, plastic, and rubber components of the fuel system that are otherwise not built to handle them.
GMC Terrain Gas Mileage Per Generation
The 1st-gen GMC Terrain has a combined gas mileage of 18 to 26 mpg using regular gasoline and 14 to 17 mpg using E-85/Flex-Fuel.
The 2nd-gen GMC Terrain has a combined gas mileage of 23 to 32 mpg depending on the engine option and drivetrain.
1st-Generation GMC Terrain Gas Mileage (2010 to 2017)
| Engine Option | MPG (City) | MPG (Highway) | MPG (Combined) |
| 2.4L Inline-4 (I4) (FWD) | 21 to 22 mpg | 31 to 32 mpg | 25 to 26 mpg |
| 2.4L Inline-4 (I4) (AWD) | 20 mpg | 28 to 29 mpg | 23 mpg |
| 2.4L Inline-4 (I4) (FWD)(E-85/Flex-Fuel) | 15 mpg | 21 mpg | 17 mpg |
| 2.4L Inline-4 (I4) (AWD)(E-85/Flex-Fuel) | 14 mpg | 20 mpg | 17 mpg |
| 3.0L V6 (FWD) | 16 to 17 mpg | 23 to 25 mpg | 19 to 20 mpg |
| 3.0L V6 (AWD) | 16 to 17 mpg | 23 to 24 mpg | 19 to 20 mpg |
| 3.0L V6 (FWD)(E-85/Flex-Fuel) | 12 mpg | 17 to 18 mpg | 14 mpg |
| 3.0L V6 (AWD)(E-85/Flex-Fuel) | 12 mpg | 17 mpg | 14 mpg |
| 3.6L V6 (FWD) | 17 mpg | 24 mpg | 19 to 20 mpg |
| 3.6L V6 (AWD) | 16 mpg | 23 mpg | 18 to 19 mpg |
| 3.6L V6 (FWD)(E-85/Flex-Fuel) | 13 mpg | 22 mpg | 16 mpg |
| 3.6L V6 (AWD)(E-85/Flex-Fuel) | 12 mpg | 17 mpg | 14 mpg |
2nd-Generation GMC Terrain Gas Mileage (2018 to 2023/Present)
| Engine Option | MPG (City) | MPG (Highway) | MPG (Combined) |
| 1.5L Inline-4 (I4) Turbo (FWD) | 24 to 26 mpg | 29 to 30 mpg | 26 to 28 mpg |
| 1.5L Inline-4 (I4) Turbo (AWD) | 23 to 25 mpg | 28 mpg | 25 to 26 mpg |
| 2.0L Inline-4 (I4) Turbo (FWD) | 22 mpg | 28 mpg | 24 mpg |
| 2.0L Inline-4 (I4) Turbo (AWD) | 21 mpg | 26 mpg | 23 mpg |
| 1.6L Inline-4 (I4) Turbo Diesel (FWD) | 28 mpg | 39 mpg | 32 mpg |
| 1.6L Inline-4 (I4) Turbo Diesel (AWD) | 28 mpg | 38 mpg | 32 mpg |
What is the gas tank size/capacity of the GMC Terrain?
The 1st-gen GMC Terrain has a gas tank size of 18 gallons (68.1 liters) for 2010 to 2015 models and 18.8 gallons (71.2 liters) for 2016 to 2017 models.
The 2nd-gen GMC Terrain has a gas tank size of 14.9 gallons (56.4 liters) for FWD models and 15.6 gallons (59 liters) for AWD models.
| GMC Terrain Generation/Model Years | Engine/Trim Level | Gas Tank Size/Capacity (US Gallon/Liter) |
1st Generation (2010 to 2017) | 2.4L I4 (SL)(2015) | 18 gal (68.1 l) |
| 2.4L I4 (SL)(2016 to 2017) | 18.8 gal (71.2 l) | |
| 2.4L I4 (SLE-1)(2010 to 2015) | 18 gal (68.1 l) | |
| 2.4L I4 (SLE-1)(2016 to 2017) | 18.8 gal (71.2 l) | |
| 2.4L I4 AWD (SLE-1)(2010 to 2015) | 18 gal (68.1 l) | |
| 2.4L I4 AWD (SLE-1)(2016 to 2017) | 18.8 gal (71.2 l) | |
| 2.4L I4 (SLE-2)(2010 to 2015) | 18 gal (68.1 l) | |
| 2.4L I4 (SLE-2)(2016 to 2017) | 18.8 gal (71.2 l) | |
| 2.4L I4 AWD (SLE-2)(2010 to 2015) | 18 gal (68.1 l) | |
| 2.4L I4 AWD (SLE-2)(2016 to 2017) | 18.8 gal (71.2 l) | |
| 2.4L I4 (SLT-1)(2010 to 2015) | 18 gal (68.1 l) | |
| 2.4L I4 (SLT-1)(2016 to 2017) | 18.8 gal (71.2 l) | |
| 2.4L I4 AWD (SLT-1)(2010 to 2015) | 18 gal (68.1 l) | |
| 2.4L I4 AWD (SLT-1)(2016 to 2017) | 18.8 gal (71.2 l) | |
| 2.4L I4 (SLT-2)(2010 to 2015) | 18 gal (68.1 l) | |
| 2.4L I4 (SLT-2)(2016 to 2017) | 18.8 gal (71.2 l) | |
| 2.4L I4 AWD (SLT-2)(2010 to 2015) | 18 gal (68.1 l) | |
| 2.4L I4 AWD (SLT-2)(2016 to 2017) | 18.8 gal (71.2 l) | |
| 2.4L I4 (Denali)(2013 to 2015) | 18 gal (68.1 l) | |
| 2.4L I4 (Denali)(2016 to 2017) | 18.8 gal (71.2 l) | |
| 2.4L I4 AWD (Denali)(2013 to 2015) | 18 gal (68.1 l) | |
| 2.4L I4 AWD (Denali)(2016 to 2017) | 18.8 gal (71.2 l) | |
| 2nd Generation (2018 to 2023/Present) | 1.5L I4 Turbo (SL) | 14.9 gal (56.4 l) |
| 1.5L I4 Turbo (SLE) | 14.9 gal (56.4 l) | |
| 1.5L I4 Turbo AWD (SLE) | 15.6 gal (59 l) | |
| 1.5L I4 Turbo (SLT) | 14.9 gal (56.4 l) | |
| 1.5L I4 Turbo AWD (SLT) | 15.6 gal (59 l) | |
| 1.5L I4 Turbo AWD (AT4) | 15.6 gal (59 l) | |
| 1.6L I4 Turbo Diesel (SLE) | 14.9 gal (56.4 l) | |
| 1.6L I4 Turbo Diesel AWD(SLE) | 15.6 gal (59 l) | |
| 1.6L I4 Turbo Diesel (SLT) | 14.9 gal (56.4 l) | |
| 1.6L I4 Turbo Diesel AWD(SLT) | 15.6 gal (59 l) | |
| 2.0L I4 Turbo (Denali) | 14.9 gal (56.4 l) | |
| 2.0L I4 Turbo AWD (Denali) | 15.6 gal (59 l) |
Conclusion
When choosing the best fuel for your GMC Terrain, you need to start with one that has an octane rating of at least 87 for the gasoline variants. Avoid using anything lower to prevent engine knock and potential damage to internal components.
But as we’ve mentioned earlier, the 2-liter “LTG” I4 turbo option of the 2nd-gen Terrain is recommended to be filled up with premium 93-octane gasoline for the best performance and fuel economy.
Once you’ve got the octane rating down, you can then start looking into compatible fuel blends such as TOP TIER gasoline, reformulated gasoline, E-10/E-15 for non-FFV models, and E-85/Flex-Fuel for FFV models.
GMC Terrain diesel models, which have the 1.6-liter I4 turbo diesel engine, are compatible with ultra-low sulfur diesel (max 15 ppm), TOP TIER diesel, and up to 20% biodiesel (B20).
Frequently Asked Questions (FAQs)
