97 GTX and marked premium

[battscrew]

any issues running premium instead of regular?

 

[jwick86]

I run premium in all my stock ski's. Its just filtered better. You won't gain anything by running higher octane unless you bump up the compression or start changing the squish. It won't hurt anything for you.

 

[kustomkarl]

Actually running high octane fuel will cause performance problems as it is designed to run on 87 octane. There are reports that it is over priced and useless unless it is pinging and requiring the higher octane fuel. It will run sluggish because the engine can't burn all the fuel. Stick to 87 Octane and not worry about it, and save money too.

Karl

 

[6KJR]

At what compression would you start to suggest people run premium? I know the Yamahas can get away with it a lot better due to the lower compression, but a couple 787s I have blow 160.

 

[jwick86]

Its not just the compression, its also the combustion chamber volume. If you check groupK or some other head modders, they will tell you after they mill the head and adjust the volume in the chamber, it becomes necessary to run premium. I believe the cut off for a 787 is around 160lbs. Not positive but I'd start there or if the modder told me to run it.

Everyone I've talked to about mods, has said run it stock or not, just cleaner fuel for your motor. I have NOT noticed ANY difference in my stock motors running premium vs regular. Neither have my friends who have same ski's, and ran regular, now to premium. One has a jet/filter kit, other is bone stock.

What mods do you have done?

 

[battscrew]

thanks for the replies - no mods done - pure stock. In my area they only have marked premium and the regular unmarked is a couple of cents more.