In my '92 Civic I used the super from Shell, Chevron, and Exxon 92 octane. I've gone to the cheaper places, and really could tell no difference in performance, and I rarely checked the mileage. Once in a while I put in a bottle of Techron additive in to keep the engine running smooth. That has helped immensely. On my '04 Accord, I still use the super stuff.

 

87 Chevron with Techron

 

always 93 at either Mobil or Exxon. Have used 87 and 89 in the past but didn't notice a significant difference but I stick with super.

 

Shell MasterCard wned: all others. Its an awsome deal for 60days and then its still descent. Their gass really does give me more miles than BP of same octane level. I used to pump 93 but now I'm at 89 and will probably go back own to 87