Do I absolutely have to use 91 octane gas in my Subaru turbo?

[sleeper8405]

I have a 2005 Subaru Legacy GT (turbo). The owners manual says that 91 or higher octane gas is recommended... but it doesnt say its required. I was wondering if I could use 87 octane (middle grade); would that hurt my engine/ turbo because of the increased engine ping?

[angie51492]

You should never use lower octane gas. Use the one recommended even though it's a bit more expensive. Using lower octane gas will diminish the performance of your car and will cause your car to use up more gas which means more money. In the long run, it's cheaper to use the recommended octane.

[Pedro S]

...yes lower grade gas will hurt the engine,,, turbos are hard on the engine.....if you dont want it trade it for a regular 4 cylinder