I came across some serious debates on what grade gas you should use for the 250. Some people are saying nothing or 87 cause everything higher is a conspiracy by the gas companies to take our money. ( that was a new one to me) And some people say they dont notice a difference between high test and regular.
So I was just wondering what grade does the manufacturer recommend for the 250 and is that what everyone is using?

 

It looks likes Kawi recommends a min 91 Research/87 avg oct (that is what I got off their website.

Personally I run regular in mine - have had no problems.

 

87 octane here, with no problems yet. I started on 91 octane but after doing some research I decided to try the cheap stuff. No detonation heard/felt, so she's ok with it

 

87 octane. tried 93 during break-in and found no difference, but that was during break-in. maybe i should try it again?

anyway, I very rarely get detonation.

 

I tried it again, and made a few discoveries...

1) There is no difference in knock, it has little or no knock at 87, so it has little or no knock at 93.
2) It has a slight boost in performance, very slight, but noticeable.
3) Gas mileage decreases slightly, which I did not expect, but is understandable due to reults from #1

 

I just keep it to 87 grade, and don't use ethanol either. If you can rev it up to the red line without having any knock, there is absolutely no reason to use a higher grade. Higher octane fuel only slows down the combustion process, which in turn means wasted unburned fuel going through an engine that doesn't have enough time to completely burn it.

It's hard to believe the 250 engine with a 12.5:1 compression ratio can run 87 oct. without knocking, but it does!

So that's why I do what I do

 

ditto