Higher octane better or doesnt matter?

[MyProto5]

Ok so I always get the plus or premium gas because my car gets better gas mileage with it [02 protege 5] and my friend just told me that unless I'm told in my manual to get higher octane it won't matter if i get regular or premium. which makes no sense cuz my car sucks up regular like its water.
(gtfo)

 

[ThrillRide]

Ok so I always get the plus or premium gas because my car gets better gas mileage with it [02 protege 5] and my friend just told me that unless I'm told in my manual to get higher octane it won't matter if i get regular or premium. which makes no sense cuz my car sucks up regular like its water.
(gtfo)

Being a young car I can't imagine why it would drink up more regular than premium. There is no need for you to buy premium unless you put a turbo kit on the p5.

 

[niky]

Only matters if your ECU is adaptive (MP3), but it could also mean you've got issues... maybe carbon build up or sensor problems... that make your car run worse on regular.