Subaru Forester: Fuel / Fuel requirements

The engine is designed to operate using unleaded gasoline with an octane rating of 87 AKI (90 RON) or higher.

Mexico only

Add a bottle of genuine SUBARU fuel additive to the fuel every 9,000 miles (15,000 km). Refer to an authorized SUBARU dealer for details.

Fuel octane rating

Using a gasoline with a lower octane rating can cause persistent and heavy knocking, which can damage the engine. Do not be concerned if your vehicle sometimes knocks lightly when you drive up a hill or when you accelerate. Contact your SUBARU dealer if you use a fuel with the specified octane rating and your vehicle knocks heavily or persistently.

RON

This octane rating is the Research Octane Number.

AKI

This octane rating is the average of the Research Octane and Motor Octane numbers and is commonly referred to as the Anti Knock Index (AKI).

Unleaded gasoline

The neck of the fuel filler pipe is designed to accept only an unleaded gasoline filler nozzle. Under no circumstances should leaded gasoline be used because it will damage the emission control system and may impair driveability and fuel economy.

Reformulated gasoline

SUBARU supports the use of reformulated gasoline when available. Reformulated gasoline has been blended to burn more cleanly and reduce vehicle emissions.

MMT

Some gasoline contains an octane-enhancing additive called MMT (Methylcyclopentadienyl Manganese Tricarbonyl). If you use such fuels, your emission control system performance may deteriorate and the CHECK ENGINE warning light/Malfunction indicator light may turn on. If this happens, return to your authorized SUBARU dealer for service. If it is determined that the condition is caused by the type of fuel used, repairs may not be covered by your warranty.

Gasoline for cleaner air

Your use of gasoline with detergent additives will help prevent deposits from forming in your engine and fuel system. This helps keep your engine in tune and your emission control system working properly, and is a way of doing your part for cleaner air. If you continuously use a high-quality fuel with the proper detergent and other additives, you should never need to add any fuel system cleaning agents to your fuel tank.

Many gasolines are now blended with materials called oxygenates. Use of these fuels can also help keep the air cleaner. Oxygenated blend fuels, such as ethanol (ethyl or grain alcohol) may be used in your vehicle, but should contain no more than 10% ethanol for the proper operation of your SUBARU.

Do not use any gasoline that contains more than 10% ethanol, including from any pump labeled, E15, E30, E50 or E85 (which are only some examples of fuel containing more than 10% ethanol).

In addition, some gasoline suppliers are now producing reformulated gasolines, which are designed to reduce vehicle emissions. SUBARU approves the use of reformulated gasoline.

If you are not sure what the fuel contains, you should ask your service station operators if their gasolines contain detergents and oxygenates and if they have been reformulated to reduce vehicle emissions.

As additional guidance, only use fuels suited for your vehicle as explained in the following description.

• Fuel should be unleaded and have an octane rating no lower than that specified in this manual.
• Methanol (methyl or wood alcohol) is sometimes mixed with unleaded gasoline. Methanol can be used in your vehicle ONLY if it does not exceed 5% of the fuel mixture AND if it is accompanied by sufficient quantities of the proper cosolvents and corrosion inhibitors required to prevent damage to the fuel system. Do not use fuel containing methanol EXCEPT under these conditions.
• If undesirable driveability problems are experienced and you suspect they may be fuel related, try a different brand of gasoline before seeking service at your SUBARU dealer.
• Fuel system damage or driveability problems which result from the use of improper fuel are not covered under the SUBARU Limited Warranty.

CAUTION

Do not let fuel spill on the exterior surfaces of the vehicle. Because fuel may damage the paint, be sure to wipe off any spilled fuel quickly. Paint damage caused by spilled fuel is not covered under the SUBARU Limited Warranty.