i ran 25 gals of racing fuel mixed with 40 gals of premium , my question do i still need to add stable for the layup during winter its 111 octane thanks rob

Yes

Several have mentioned a product besides stabil as well, I don't recall the name but I seem to recall it treated more gallons.

Stabil has a terrible oder too. It can get out of a tank through the vent lines and stink up your shop.

ABSOLUTELY, and run the motors for a few mins

I have been told that the octane evaporates off over time

does anyone know if that is true ?? and by how much ???

Rob -

Your best bet is to try and get the fuel out it will be useless by Spring.

I use my pump and put it in my truck, four wheeler, etc...then i know I'm starting with good fuel in the Spring.

I'm sure many others will suggest topping off the tank, but with the ethanol and todays fuel, you'll have 100 gallons of useless fuel.

yea i can disconect my electric fuel line and pump it out ever got uses for the fuel fill one work truck this week thanks rob

I was told by a local race fuel distributor that their fuel will not loose octane over time like regular gasoline.
Since you are mixed with gasoline, add the stabil. Will only cost you the price of a couple gallons of race fuel.

Use Naptha. Do a check on here on stabil. I posted a while back.
The race fuel will make you absorb more water too, I have seen it. BBB