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Types Of Gas A Subaru Forester Takes (All Generations)

We’ve written extensively about the Subaru Forester, its capacities, and various features on this blog. Today, we will talk about what fuel this SUV needs and what kind of fuels are strictly prohibited. Let’s start with a quick answer:

Most Subaru Foresters with a non-turbocharged engine make use of regular unleaded gasoline with an octane rating of 87. Most Subaru Foresters with a turbocharged engine make use of premium gasoline with an octane rating of 91 or 93, depending on the model year.

However, that doesn’t tell the whole story. Below we’ve outlined recommendations and requirements for different kinds of fuels and fuel additives. Furthermore, we discuss the fuel mileage of all generations ever manufactured, and we give an overview of the tank size of these generations. Read on!

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Octane Requirements Per Generation

  • Subaru Foresters manufactured between 1999 – 2002 make use of regular unleaded gasoline with an octane rating of 87 AKI. Premium gasoline is not recommended for this model since it will have no performance and/or durability benefits over regular gasoline.
  • Subaru Foresters manufactured between 2002 – 2005 make use of premium unleaded gasoline with an octane rating of 91 AKI for the models without a turbo. Foresters with a turbocharged engine make use of premium unleaded gasoline with an octane rating of 93.
  • Subaru Foresters manufactured between 2005 – 2013 make use of regular unleaded gasoline with an octane rating of 87 AKI for the non-turbo models. The Foresters with a turbocharged engine make use of premium unleaded gasoline with an octane rating of 91. These engines may use 87 AKI temporarily when 91 AKI is not available.
  • Subaru Foresters manufactured between 2013 – 2018 make use of regular unleaded gasoline with an octane rating of 87 AKI for the non-turbo models. The Foresters with a turbocharged engine make use of premium unleaded gasoline with an octane rating of 93. These engines may use 87 AKI temporarily when 91 or 93 AKI is not available.
  • Subaru Foresters manufactured between 2018 – Present-day make use of regular unleaded gasoline with an octane rating of 87 AKI. Premium gasoline is not recommended for this model since it will have no performance and/or durability benefits over regular gasoline.

Also read: Subaru Forester Towing Capacity: Can It Tow A Trailer, Boat, Or Jet Ski?

Reformulated Gasoline

Reformulated gasoline is the gasoline that’s sold in the United States and which is designed to burn more cleanly than non-reformulated gasoline. Originally it was first mandatory in the state of California. However, in recent years more states and regions have made reformulated gasoline the only gasoline that’s legal for sale. This holds especially true in regions where the air quality is considered to be average or poor.

It’s good to know that the use of reformulated gasoline is not a problem for all generations of the Subaru Forester. Furthemore, Subaru actually advises you to use this kind of gasoline whenever it’s available. Also, no extra maintenance needs to be carried out when using this gasoline.

Also read: The Exact Bolt Pattern Of A Subaru Forester

Oxygenated Blends Of Gasoline

Some suppliers sells oxygenated blends of gasoline. The oxygenated blends may contain MTBE, ethanol or methanol. Subaru is consistent in its advise for the Forester in terms of using these fuels in the Forester. The guidelines are as follows:

  • Fuels with ethanol can be used as long as the percentage of ethanol does not exceed 10%.
  • Fuels with MTBE can be used as long as the percentage of MTBE does not exceed 15%.
  • Fuels with methanol can be used as long as the percentage of methanol does not exceed 5% and if it is accompanied by sufficient quantities of the proper cosolvents and corrosion inhibitors required to prevent damage to the fuel system.

Gasoline With Additives

In today’s market, there are many additives available for fuel that are designed to boost octane levels or provide extra cleaning for the internals of the engine. In general, it’s advised you do not add any additives yourself to the fuel you’re using. The reason for this is the fact that some of these additives contain silicone or metallics that will damage the internal components of the engine and the fuel system.

Instead it’s advised you buy gasoline from TOP TIER retailers. TOP TIER gasoline already has all the additives mixed into it to make sure your engine stays clean and safe. You can find a TOP TIER retailer at toptiergas.com.

Knocking After Refueling

Hearing a slight knocking sound is never a reason for concern. Especially in situations where the Forester is under heavy stress (towing, driving up a hill) a slight knocking noise is normal. However, there are some situations in which knocking happens right after refueling.

If this knocking sound is louder than normal then this is a reason for concern. It’s advised to stop the car and contact your dealer to seek assistance. It’s very likely you’ve used fuel with a lower than recommended octane rating. Continuing to drive with the vehicle will damage the car and void the warranty.

Also read: Subaru Forester Transmissions: Overview, Problems, Fluids

Tank Size Subaru Forester

  • Subaru Foresters manufactured between 1999 – 2008 and 2013 – 2018 have a fuel tank size of 15.9 gallons or 60 liters.
  • Subaru Foresters manufactured between 2008 – 2013 have a fuel tank size of 16.9 gallons or 64.1 liters.
  • Subaru Foresters manufactured between 2018 – Present-day have a fuel tank size of 16.6 gallons or 63 liters.

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