Unleaded and Premium Unleaded Gas - Synergy Fuel from Exxon and Mobil

Our gasoline  

Introducing Exxon and Mobil SynergyTM Gasoline

Engineered with 7 key ingredients, working together for better gas mileage.**

Meet the team:
Fuel Detergent 1 – helps provide excellent protection against intake valve deposits in traditional PFI (Port Fuel Injector) injection engines
Fuel Detergent 2 - helps provide Intake Valve Deposit protection for PFI engines and also provides additional protection for modern Direct Injection engines. Cleaner engine parts can lead to better gas mileage
Anti-Adhesion Compound - helps prevent fuel detergents from forming a sticky film on the intake valves; which in turn helps prevents cold start problems at cold temperatures
Corrosion Inhibitor - helps prevent rust in fuel distribution system and/or key engine parts the fuel comes into contact with such as the gas tank and the intake valves
Demulsifier - helps keep water from getting entrained in our additive in the distribution system. Helps prevent accumulation of water in your gas tank by allowing it to be separated and removed
Solvent Fluid - enables the additive ingredients to stay mixed and to flow, and not freeze at very cold temperatures
Marker Molecules - ensures we can determine the correct amount of our unique additive is added to our gasoline

TOP TIER® SynergyTM gasoline – quality you can depend on

When you fill up at an Exxon- or Mobil- branded stations, you can be confident you’re getting TOP TIER gasoline, every time. Available in three octane levels, our Synergy™ gasoline has been engineered with 7 key ingredients and developed to clean up intake valves, which help improve gas mileage and performance.*

Exxon and Mobil SynergyTM gasoline grades

Gasoline grades are based on octane ratings. The higher the octane number the greater the fuel’s resistance to knocking or pinging during combustion. In most areas of the country our regular gasoline is 87 octane, midgrade is 89 and premium is 91 to 93. To determine which Synergy™ gasoline grade is best for your vehicle, check your owner’s manual.

Learn more about octane ratings >

  • Exxon and Mobil Regular Gasoline

    Octane 87

    Our regular grade unleaded gasoline was developed to meet the needs of most vehicles in America and is our most popular gasoline.

  • Exxon Plus and Mobil Special Gasoline

    Octane 89

    Our midgrade unleaded gasoline was developed to meet the needs of vehicles that can benefit from a higher octane, such as some sport vehicles and high performance cars.

  • Exxon Supreme and Mobil Super+ Gasoline

    Octane 91–93

    Our premium grade unleaded gasoline was formulated with a higher octane level and additional detergent additives to meet the demands of some of today’s most advanced engines. It generally has an octane level of 93 but is blended with an octane level of 91 or 92 in certain areas of the U.S.

FAQs about gasoline

When you purchase gasoline at an Exxon- or Mobil-branded gas station, you can be sure your vehicle is receiving TOP TIER fuel. TOP TIER is a more stringent standard of gasoline that was established by a governing body of automakers and is recommended in vehicles’ owner manuals because it exceeds the minimum level of detergent additives mandated by the Environmental Protection Agency (EPA). Exxon and Mobil gasoline contains significantly higher detergent levels than EPA requirements and has passed a series of deposit control performance tests, resulting in it being certified TOP TIER. Not only does our gasoline help keep vital engine parts clean, we also remove deposits as you drive.
Yes! Detergents are added to gasoline to help clean vital engine parts, including fuel injectors and intake valves. While the EPA has mandated that all gasoline marketed in the United States contains detergents since 1995, our gasoline contains significantly more than the minimum quantities required. A gasoline detergent is a lot like a household detergent, helping to remove any harmful deposit buildup, which can lead to better fuel economy.*
If you filled your tank prior to the 1990's, you might remember that there were two choices of gasoline: "regular" and "unleaded." At the time, "regular" gasoline contained tetraethyl lead, which served as an octane booster in fuel. All vehicles manufactured after 1975 are built with catalytic converters and require unleaded gasoline. Catalytic converters help convert pollutants in exhaust to less toxic gasses such as carbon dioxide, nitrogen, and water vapor. Due to environmental concerns, leaded gasoline was phased out in the 1990’s and can no longer be sold at any gas station in the United States. Today, "regular gas" no longer refers to gasoline with lead content, but rather to a certain grade of unleaded gasoline.
The performance of gasoline is determined by multiple factors, including its antiknock quality (also known as octane rating), its volatility, and its detergency. Check your owner’s manual to see what octane rating is right for your vehicle.
Antiknock, also known as octane rating, is a measure of the gasoline's ability to resist knocking or pinging during combustion. Since it is gasoline vapor rather than liquid fuel that ignites, the air-to-fuel mixture must be correct for smooth combustion. The higher the octane rating, the greater the engine's resistance to knock. Some of the problems associated with knock are overheating of critical engine parts – namely valves, pistons and spark plugs. To minimize the effects of knocking, modern engines are equipped with knock sensors, which temporarily delay the spark timing in the piston’s compression cycle. While this prevents audible knocking, delaying the ignition spark also sacrifices engine efficiency.
Volatility refers to a series of characteristics that measure a fuel’s tendency to vaporize at a given temperature. Since gasoline must vaporize before mixing and burning with air, formulating fuel with the correct volatility is critical for achieving good drivability. High volatility gasoline vaporizes more readily than low volatility fuel and is frequently blended during the winter season to ensure easy cold startup and smooth warm up. In hot weather, gasoline that is too volatile can cause vapor lock and other hot fuel handling problems. Exxon and Mobil gasoline is carefully formulated on a seasonal and geographic basis to provide the correct vaporization characteristics for proper vehicle operation.
Detergency is the performance characteristic of a gasoline that refers to its ability to clean and protect the fuel delivery system, including the carburetor or fuel injectors, and intake valves. A gasoline detergent is fundamentally like a household detergent. It is a molecule that affixes itself to dirt particles. As gasoline passes through a car's engine, the molecule helps clean away dirt particles and helps to prevent any harmful deposit build-up.
  • Quality fuels to get you where you're going

    Discover what steps we take to ensure the quality of our fuels.

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  • The right fuel for your vehicle

    Get the most out of your engine, and your journey, with Exxon and Mobil SynergyTM gasoline and diesel.

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  • Get more out of every trip

    Explore our comprehensive list of tips to help you improve fuel efficiency and get more out of every trip.

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  • Introducing Exxon and Mobil SynergyTM Gasoline

    Learn more about our new SynergyTM gasoline, engineered with 7 key ingredients to help you get better gas mileage.**

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*Applies to Exxon- and Mobil-branded gasoline compared to gasoline meeting minimum U.S. government standards. Actual benefits vary depending on factors such as vehicle type, driving style and gasoline previously used.

**Fuel economy improvement is based on Synergy-branded gasoline compared to gasoline meeting minimum U.S. government standards. Actual benefits will vary based on factors such as vehicle type, driving style and gasoline previously used. Exxon, Mobil and Synergy are trademarks or registered trademarks of Exxon Mobil Corporation or one of its subsidiaries.