Jim - since you have over 200K on your engine you obviously know how to take care of the car despite running less than reccomended octane
- BUT -
Stazi is right, there is NO WAY your engine is running at its top performance or mileage on 87. Your spark timing is retarded and you are running richer than optimum. Now if you drive it real nice never run the egine to redline at WOT, maybe you won't notice anything. But if you dyno your car on 87 and then on 93 (after the engine has appropriately "learned") then you would undoubtedly see better results on premium.
Oh and why even bother running 87 winter piss blend? You yourself stated you heard a slight ping, so why even take the risk?
