Octane rating?

[fluxpato]

The owner's manual calls for gasoline with an octane rating of 87 or higher. The engine (1.5L) has a pretty high static compression ratio of 10:1. I'm wondering if using a higher octane gas would provide a boost in performance/fuel economy, or be better on the engine in general? I know that using a higher octane than necessary is unnecessary and can even damage an engine in some cases, but those vehicles have lower compression ratios and their manuals don't necessarily have the "or higher" clause (my last vehicle had a compression ratio of 9:1 but the manual only said 87 octane.) Can anyone lend some insight? I have no car experience besides what I read on the interwebs, so please correct me if I'm way off-kilter here. Thx

 

[njaremka]

if it was tuned for 87 and thats what the manual tells you to use, there will be no benefit to running higher.

on the other hand, if the manual tells you to use 91+, you will see a performance decrease if you decide to run less.

 

[Richard_rsp]

I always give a tank of premium a shot to see what it does (if anything). In previous vehicles, some its helped, some it hasnt. My VW Golf 2.5 and Civic 1.8 seemed to really like 89 octane during the summer months, so i continued to run it...

I have tried 87, 89, and 93 in the Mazda2, and even in the 95+ degree weather we are having, 87 octane seems to run the best for me. I monitored the mileage, and it actually seemed a bit worse with premium in my experience.