My brother informed me that he runs his v-8 suv on 89 octane. He says he gets one extra m/g This way and that 89 octane is .10 pr gallon more than regular. So On 40 gallons of fuel he pays $4 more and gets 40 extra miles. I started doing some math....(Oh No!!!!) and figure that if the MH gets an extra .18 extra miles per gallon that the 89 octane would be worth it. (cheeper) Has anyone tried this? Here in the tax capital of the world (NY) 87 octane is at $4.13/gal 89 octane is $4.23 a gal. Ok, I cant type/spell or do math..... and there are rumors that I went to a good university...(see:drinking) Anyway I am curious if anyone has an opinion or has tried it. Thanks.