Gasoline options for Outback XT 2025

[sailkris]

should I use premium 91 octane or regular 87

 

[bmart]

What does the manual say? Probably on the filler door too.

 

[Dick Foster]

If you have a turbo charger, or any forced induction engine, you need to run premium grade, higher octane fuel to prevent pre ignition aka knock. Otherwise it's regular, lower octane fuel. Higher octane fuel is actually harder to burn and that's how it delays the onset of ignition and therfore suppresses knock.

 

[bmart]

Any mods may alter this too.

 

[Dick Foster]

should I use premium 91 octane or regular 87

Likely the regular cheap stuff. Don't use higher octane than needed or necessary. It's worse for the engine, while wasting money.

 

[msilverm]

My understanding is the manual for the XT turbo charged engine does NOT recommend 91 octane. I agree with the earlier comment that Turbo cars generally require higher octane. I have a 2021 Outback XT. Dealership Service personnel that i have spoken with do not recommend higher octane. In Colorado, where 85 octane is available, they recommend a minimum of 87 octane. That said, I generally use 89 octane. I have not had any difficulty with knock.

 

[sethm]

My 2020 XT requires minimum 87 octane also in Colorado. My manual explicitly states 87 minimum- if you have warranty problems it's from low-octane fuel, it could be voided. Additionally - make sure you use TopTier fuels with the additives and cleansers. If you run cheap supermarket gas you will experience issues. I had to run Techron cleaner through mine when I ran cheap gas.

 

[piste]

should I use premium 91 octane or regular 87

yes

 

[Dick Foster]

If it's a turbo boosted engine, it wants and needs premium fuel. As for me I'm enjoying buying the cheap stuff after many years of premium fuel in two vehicles, one with a turbo, the other supercharged.

 

[piste]

should I use premium 91 octane or regular 87

yes

 

[Grumpy1950]

According to the manual, minimum of 87 octane required unless you are towing. If you are towing, 91 octane is required.

 

[Train Dan]

Fill door says 87, so I'll use 87. Yes, it's a turbo.
Dan

 

[bmart]

Interesting. My turbos are all 93+.

 

[msilverm]

Dan, the owner's manual says the CVT transmission fluid is lifetime. No need to change the fluid. That is nonsense. Japan Subaru says change it every 30,000 miles or 3 years. Accordingly, just because Subaru US says it, doesn't make it the gospel. If you are driving a turbo and you are pushing the car hard, I suggest 89 or 91 octane. If your driving does not maximize the turbo, 87 may be fine. Mark