so my friend has a 2007 yz450f and he puts 112 octane race gas in it. and its $10 a gallon. is it necessary to run race gas? my yz400f says specifically not to. i just use 91 octane.
If it says to use 91 and you know for a fact it doesnt have any mods, go with 93 octane.
Some people think you get more power with higher octane fuel, that is a myth.
What does it say on the fender of his 450? On my 250F is says to use 95 research octane (which is the same as 93).
Sounds to me like maybe the dealer is feeding him a line of BS.
The biggest difference, as I understand it, in the pump fuel / race gas issue is consistantcy. I've run both, sometimes run 50-50, but I mostly run pump fuel. I love the smell of the race gas but I can't justify the cost for my riding ability. I imagine your buddy buys the $10/gal stuff from the dealer that told him to run it, LOL.
If the bike runs good and doesn't knock under load, super should be just fine.
As a side note. I have my bike ported and use race gas to make jetting easier. VP seemed way to expensive every where I looked too. I went to the local drag strip an found Sunoco 110 (CAM 2 blue) for $5.10 a gallon. It's sold at a pump so you can buy only what you need. There are a few gas stations on the way to the track that carry it too. The fuels look very similar chemically.