What Is The Right Gas Type For My Truck?

Everything You Need to Know About Gas Octanes and Diesel Requirements for Your GMC Truck at John Holt GMC

Key Takeaways

• The GM owner’s manual will outline the best gas to use.
• A higher octane rating doesn’t mean it’s a higher-quality gas.
• Octane rating is a measurement of engine knock.
• Most common octane ratings: 87 Regular, 89 Mid-Grade, 91/93 Premium

When it comes to new model GMC trucks like the always popular and heavy-hauling GMC Sierra 1500, Sierra 2500, and 3500, or the off-road-capable GMC Canyon, families and drivers know that nobody provides deals quite like John Holt GMC. As the go-to GMC dealership for drivers in Chickasha, Duncan, Lawton, Blanchard, and surrounding communities, John Holt GMC always exceeds expectations on new and GMC-Certified pre-owned trucks and SUVs.

A frequent inquiry we receive from customers involves determining the correct fuel grade for their GMC vehicles. Because GMC trucks are precision-engineered to perform optimally on specific fuel octanes, understanding these requirements is essential for maintaining vehicle longevity and efficiency. Below is an overview of why selecting the appropriate fuel is crucial, along with a recommended guide to the ideal fuel grades for our most popular GMC pickup models.

Understanding Gasoline Octane Ratings

The best approach to determine which gas to use for your GMC truck is to first check your owner’s manual. That manual will define the best fuel for your engine based on GM’s recommendation. As the original equipment manufacturer (OEM), GM designed your truck’s engine to attain peak performance using a specific gas or octane rating.

The most common gasoline octane ratings include 87 regular, 89 mid-grade, and 91/93 premium. However, don’t assume that the higher rating immediately equates to a better or higher quality of gasoline. The octane rating is simply a measurement of the gas’s ability to resist premature engine knock, which is when the combustion of the gas within the engine happens at the wrong time.

What Type of Gas Does A GMC Sierra 1500 Need?

The GMC Sierra 1500 is one of the best-selling and most sought-after pickups in America. From weekend camping getaways, heavy-hauling, and hunting to farmers and contractors needing to tow a heavy load, the GMC Sierra 1500 is the go-to GMC truck for John Holt GMC customers. The type of gas that should be used depends upon the type of engine your GMC Sierra 1500 has.

Both the 2.7-liter TurboMax and the 5.3-liter V8 use 87-octane regular unleaded. The 6.2-liter V8 uses Premium 91-octane or higher, while the 3-liter Duramax Turbo-Diesel should use an ultra-low sulfur diesel fuel (ULSD No. 2-D).

• 2.7L TurboMax: 87-octane regular unleaded
• 5.3L V8: 87-octane regular unleaded
• 6.2L V8: Premium 91-octane or higher recommended
• 3.0L Duramax Turbo-Diesel: Ultra-low sulfur diesel fuel (ULSD No. 2-D)

What Gas Does A GMC Sierra HD Need?

If you own either a GMC Sierra 2500 HD or 3500 HD, then you’re dealing with either the 6.6-liter V8, which needs 87-octane regular unleaded, or the 6.6-liter Duramax Turbo-Diesel and its ultra-low sulfur diesel. Again, always check the owner’s manual and never put gasoline into a Duramax Diesel engine.

Understand that gasoline and diesel engines are engineered and designed differently. As such, they have different internal engine components and run on different fuel.

• 6.6L gasoline V8: 87-octane regular unleaded
• 6.6L Duramax Turbo-Diesel: Ultra-low sulfur diesel fuel (ULSD No. 2-D)

Why Does the Type of Gas Matter?

When GMC designs and engineers a truck or SUV, they design the engine around specific fuel needs. Thousands upon thousands of hours go into a precision-engineered GMC engine, and tests are endlessly run to ensure the engine’s optimal performance using a specific type of gas or fuel.

Once GMC identifies the type of octane, they lock that fuel in. Using anything less than the suggested gas octane can lead to engine knock, which can lead to engine damage. Given how much GMC trucks tow and haul, using the right type of gas is especially important to ensure the engine produces the required horsepower and torque. It’s the same for diesel engines. They are designed and optimized to run on specific types of diesel to attain the torque and horsepower needed to do the heavy hauling and towing they’re rated for.

Does Premium Gas Improve The Performance of GMC Trucks

One of the biggest misconceptions that truck owners make is assuming that premium gas improves the performance of their truck and its engine. A higher octane rating on a gas doesn’t mean it’s a higher quality gas, and it doesn’t provide better fuel economy. Putting premium gas into your GMC truck when it’s not needed won’t improve the performance and is largely a waste of money. Ultimately, it’s all about following GMC’s recommended fuel and referring to the owner’s manual at all times. If you have questions about your GMC truck and need to know what type of gas or diesel to use based on the age of your GMC pickup, contact us today!