What is meant by Premium fuel being 'Recommended?' I don't understand if this means only that the performance of the engine will be better with 91+ Octane fuel, or if it means that Regular grades are to be used only in emergencies. The engine seems to run very well with any fuel I have used, both Regular and Premium.
Is Premium considered to be 91 Octane?
- Note - no mention of additive packages. Based on my use over 10,000 miles with various grades of fuel, running Premium in this engine is right up there with the 3,000 mile oil change. but here is the official response from SOA.
Thank you for taking the time to contact us. We hope that you have been enjoying your 2006 Outback 3.0R Wagon.
The 3.0-liter H6 engine is designed to operate using unleaded gasoline with an octane rating of 91 AKI or higher. Regular unleaded gasoline with an octane rating of 87 AKI or higher may be used. This is not just for emergency situations. You can use regular unleaded fuel in your vehicle on a regular basis. However, for optimum engine performance and driveability, it is recommended that you use 91 AKI or higher grade unleaded gasoline.
You may experience reduced output, poor accelerator response, and reduced fuel economy when using gasoline with an octane rating lower than 91 AKI, depending on your driving habits and conditions.
If you experience any of those conditions while using a lower octane rated fuel, you may want to return to using 91 AKI octane rated fuel as soon as possible. Additionally, if your vehicle knocks heavily or persistently, or if you are driving with heavy loads such as when towing a trailer, the use of 91 AKI or higher grade unleaded gasoline is required
Thank you for the opportunity to be of assistance. If you need any future assistance, please feel free to contact us again.
John J. Mergen
Subaru of America, Inc.
Customer/Dealer Services Department