Need to fill up with premium gas? Learn all about our best fuel ever, Synergy Supreme+™
Ready to treat your engine right? With Synergy Supreme+ premium quality gas, you can keep your engine 3X cleaner for better gas mileage.‡ That means it’s not just our best fuel ever – it could even be your engine’s favorite fuel ever.
Synergy Supreme+ premium gas generally has an octane level of 93, but may be blended and sold at an octane level of 91 or 92 in certain areas of the US. So what are some of the benefits of premium gas with a high octane level?
Octane ratings are a measure of fuel stability. Using a lower octane fuel than required for your vehicle may damage the engine and emissions control system over time. So when it comes to regular gas vs premium, 91-93 octane gas provides improved performance and fuel economy in vehicles designed to run on premium gasoline. Every time you fill up with gasoline, you’re helping keep your engine happy.
Our gas offers better clean for better gas mileage
Fuel injectors – like spray bottles – don’t work well when they’re clogged. When it comes to functionality, fuel injectors are an essential part of your car’s engine, delivering fuel at the right time to ensure efficient combustion. Some lower tier gas can leave deposits on fuel injectors, resulting in decreased performance. This is one of the big differences between premium gas vs regular that can make a big impact.
Synergy Supreme+ premium gas contains detergent that helps remove deposits – for cleaner fuel injectors, better fuel economy and smoother engine operation. Here’s how it works:
- Deposits accumulate on port fuel injection (PFI) intake valves and gasoline direct injection (GDI) fuel injectors
- Our Synergy Supreme+ premium gas contains significantly more cleaning agents than federal standards require leading to outstanding cleanliness
- It keeps your engine clean by reducing deposit buildup
- It even cleans up your engine by removing existing deposits left behind by gasoline that meets minimum government standards††
Premium gas helps reduce friction and protect against engine
Whether it’s your dancing shoes or engine parts, friction means wear and tear. When moving engine parts aren’t protected, friction can contribute to erosion and wear, not to mention the extra strain on your engine caused by the heat. Excess friction might reduce engine efficiency and performance with time. By fueling up with premium gasoline, you’ll help safeguard your engine from friction.
We added a friction modifier to Synergy Supreme+ premium gas to prevent friction and provide you with our best engine protection ever. What that means for your vehicle:
- Our friction modifier reduces wear and tear by 30%‡‡
- It prevents metal surfaces from rubbing together, which can lead to improved performance and fuel economy
- You get a gasoline that protects vital engine parts
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Official fuel supplier for the Porsche Carrera Cup North America
As the official sponsor for this race series, Synergy Supreme+™ premium gas helps keep engines 3X cleaner for better gas mileage.‡ And during each race week this year, you can earn 18¢ in points/gallon every time you fuel up — that’s 3X the points!*
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Learn about our Synergy Diesel Efficient™ fuel
Synergy Diesel Efficient fuel is fully formulated to help keep commercial vehicle engines cleaner for 2% better diesel fuel economy.** Available only at Exxon™ and Mobil™ stations.
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Download the Exxon Mobil Rewards+™ app
It’s the convenient, fast and secure way to pay for gas, earn points and get rewarded through the Exxon Mobil Rewards+™ program. Start saving with every fill-up of gasoline.
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Exxon Mobil Smart Card+™
New accounts only earn 40¢/gal* or more! The 30¢/gal* bonus discount applies for the first month after account open date. You will receive ongoing fuel savings of 10¢ per gallon* on regular, mid-grade and diesel fuel and 12¢ per gallon* on Synergy Supreme+™ premium gas at the point of sale.
Learn more about Exxon Mobil Smart Card+™
*For select Exxon Mobil Rewards+ members only. Earn 3x the points (18 points per gallon) when you make a loyalty purchase of Synergy Supreme+™ premium gas (eight-gallon min. and maximum 300 earned points per transaction) between 12:00:00 a.m. CT, 04/28/25, and 11:59:00 p.m. CT, 05/04/25; 12:00:00 a.m. CT, 06/09/2025, and 11:59:00 p.m. CT, 06/22/25; 12:00:00 a.m. CT, 07/28/2025, and 11:59:00 p.m. CT, 08/03/25; 12:00:00 a.m. CT, 09/15/2025, and 11:59:00 p.m. CT, 09/21/25; and 12:00:00 a.m. CT, 10/06/2025, and 11:59:00 p.m. CT, 10/19/25. For new Exxon Mobil Rewards+ members, registration can be completed through the Exxon Mobil Rewards+ app or through the website: https://www.exxon.com/en/rewards-program. Offer eligibility requires at least one purchase of Synergy Supreme+ premium gas before the offer period. Offer can be earned multiple times throughout offer period. Bonus points will automatically be applied to account. Terms and Conditions apply.
‡ Engine keep-clean benefits based on Synergy Supreme+ gas compared to Synergy regular gas in port fuel injected engines. Actual benefits are based on continuous use and may vary depending on vehicle type, driving style, and gasoline previously used. Concentration and availability of our proprietary additive package may vary based on factors beyond our control.
‡Based on comparison of Synergy Supreme+ gas compared to Synergy regular gas in port fuel injected engines. Actual benefits are based on continuous use and may vary depending on vehicle type, driving style, and gasoline previously used. Concentration and availability of our proprietary additive package may vary based on factors beyond our control.
††Based on comparison of Synergy Supreme+ premium gas to gasoline that meets minimum government standards. Actual benefits are based on continuous use and may vary depending on vehicle type, driving style, and gasoline previously used. Concentration and availability of our proprietary additive package may vary based upon factors beyond our control.
‡‡Based on Synergy Supreme+ gas compared to gasoline meeting minimum government standards. Wear reduction was measured by an industry standard lubricant test. Actual benefits are based on continuous use and may vary depending on vehicle type, driving style, and gasoline previously used. Concentration and availability of our proprietary additive package may vary based on factors beyond our control.
**Claims apply to Exxon and Mobil Synergy Diesel Efficient-branded fuel compared to diesel fuel without detergent additive. Actual benefits will vary depending on factors such as vehicle/engine type, driving style and diesel fuel previously used.
*Subject to credit approval. New accounts only. The 30¢-per-gallon bonus discount applies to the first month after your account open date and will be paid as a statement credit within 1 to 2 billing cycles. You will receive ongoing fuel savings of 10¢ per gallon on regular, mid-grade and diesel fuel and 12¢ per gallon on Synergy Supreme+™ premium gas, which will be received as a reduced fuel price at the point of sale. In the event discounts at the point of sale are unavailable for any reason, you will receive the earned discounts as a statement credit within 1 to 2 billing cycles. You can earn 5% back in rebates on your first $1,200 in Exxon™ and Mobil™ non-fuel purchases made each year with your card at Exxon or Mobil locations. You will not earn rebates on Exxon or Mobil non-fuel purchases in excess of $1,200 each year. Rebates will be earned as a statement credit. Qualifying in-store purchases exclude lottery tickets, money orders and gift cards. Exxon Mobil Rewards+™ points will not be earned on purchases made with the Exxon Mobil Smart Card+™ credit card. Terms & Conditions of the Exxon Mobil Smart Card+™ Program apply.
*Based on comparison of engine cleanliness from using Synergy Supreme+ gas compared to Synergy regular gas in port fuel injected engines. Actual benefits are based on continuous use and may vary depending on vehicle type, driving style, and gasoline previously used. Concentration and availability of our proprietary additive package may vary based on factors beyond our control.
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