what do you use...

[DarkHadou SP23]

what octane do you use for your mazda3 and which one is the best to use

[Zogboy]

the cheap stuff

[jgeib]

The smart decision in this case is to use 10% blend ethanol. Not only will it help keep the engine clean and moisture free it is usually cheaper and is a couple points higher octane. The alcohol absorbs any water in the tank, and also makes the fuel burn slower and more complete resulting in less leftover crap in the exhaust. I've never ran anything but 10% blend ethanol in any of my vehicles (2001 4.7 Dakota, 1997 Saturn SC2, 2004 Mazda 3), and have never had any fuel related issues in any of them. I even run it in my motorcycle. I've used it from day one in our Mazda 3, runs great always. Last but not least ethanol is made here in the United States by U.S. farmers from corn and not overseas. Every drop we burn of U.S. fuel instead of MiddleEast fuel the better. I know I'm getting tired of the fuel prices, anyway I can help the better! Sorry I got on a rant but just thought I needed to say that. Thanks,

[arfman]

The manufacturer recommends just using the normal stuff at 87, there is no need to go higher

[DarkHadou SP23]

i use 91 but ive been readin on how it might be bad for your engine tho

[mazdatech177]

use 87 octane in mazdas, using high test only doubles the carbon building process. mazda in past told its customers to use 93 octane in the millenias, but found it was gunking these engines up at double the rate of 87.... something to do with lower btus in the 93 and the slower burn time.