Frequently Asked Questions

TOP TIER™ is a fuel performance standard written by auto manufacturers to assist in keeping the engine cleaner, thus resulting in improved customer experience. Since auto companies are not able to dictate fuel regulations or fuel standards, the TOP TIER™ logo serves as an indication of a station where the fuel marketer is supportive and offers the vehicle manufacturers' request for higher standards in fuel. The ultimate goal of the program is satisfaction of our common customer - the vehicle owner.

No. Premium describes a grade of fuel intended for use in performance engines with higher compression ratios, which may be damaged when using lower octane grade fuel. TOP TIER™ fuel marketers are required to use TOP TIER™ for all for all octane grades of gasoline and diesel sold at their stations. TOP TIER™ is a standard in fuel many automakers feel is necessary for acceptable engine cleanliness performance for all vehicles, regardless of octane requirements. All engines will benefit from a higher standard in cleanliness resulting in a vehicle performing as intended: noticeable in longevity, reduced down time, minimized emissions, and higher customer satisfaction.

If you are fueling up your diesel-powered equipment, your owner’s manual may also make recommendations beyond the use of TOP TIER™ Diesel Fuel.

Fuel delivery trucks usually have separate compartments allowing them to carry different fuels on the same load to various customers.

Retail outlets enrolled in the TOP TIER™ program are contractually committed to selling fuel that meets the TOP TIER™ standard.  This means they are supplying fuel that contains an approved additive at the right concentration that does not contain other additives known to harm engines. In addition, TOP TIER™ licensed retailers are monitored for quality through unannounced random auditing.

Please note that stations can enroll in the gasoline and diesel program separately, so always look for the gasoline or diesel logo.

All TOP TIER™ licensed brands are formulated to meet the stringent requirements for TOP TIER™ fuel. Ten leading automotive manufacturers create the TOP TIER™ Detergent Gasoline specification and four leading diesel manufacturers back TOP TIER™ Diesel Fuel. We recommend any of the brands enrolled in the program. Please check your owner’s manual for the octane level required for your vehicle. 

TOP TIER™ Detergent Gasoline brands
TOP TIER™ Diesel Fuel brands

Formulations are proprietary to each company, however, each formulation is screened for compliance to the TOP TIER™ requirements.

TOP TIER™ is a higher standard of fuel which can benefit all engines so you can feel confident using it in any vehicle.

The TOP TIER™ program does not have any direct data regarding the fuel sold on military bases.  These stations are not enrolled in the TOP TIER™ program.  We encourage you to use their Contact Us page to let them know that TOP TIER™ fuel is important to you.

Some convenience stores do sell fuel brands that are TOP TIER™ licensed and meet the stringent TOP TIER™ specifications. You can find the list of TOP TIER™ gasoline brands here, and diesel brands here. If the brand of gasoline or diesel on the signage or the dispensing pump is not on our brand list, the fuel is not licensed to be TOP TIER™. 


Although the technology and mechanical equipment for direct fuel injection differs from carbureted systems, the short answer is that the “keep clean” effect in the two different fuel systems may not differ greatly. The data and information that the sponsoring engine manufacturers have is not available in the public domain, but AAA conducted an independent investigation comparing the minimum EPA detergent levels to TOP TIER™ Detergent Gasoline. The full report is available for free download here.  AAA did a great job showing where in the engine you can benefit from gasoline meeting the TOP TIER™ performance standard and even commented on GDI engines (see section 2 of their report on pages 9 and 10; and the sub-section on emissions found in section 5.3 – page 19).

TOP TIER™ licensed brands are formulated to meet the stringent requirements of ten leading automotive manufacturers and four leading diesel manufacturers. The majority of automakers and engine manufacturers today do not recommend adding any additives to the fuel. Please consult your owner’s manual to find out if using aftermarket fuel additives is recommended for your vehicle.