I've been running united E85 for the past 13000km. After getting the car tuned on E85 the first 6000km the car ran and idled perfect. Then over the next 5000km the car would occasionally stall when coming to a stop and idle a bit rough , made it hard to diagnose because 80% of the time the car would run fine . I started using Lucas upper cylinder lube and after three tanks the car started running perfect again and hasn't stalled or run rough for the past 1000km. Now when stopped the only way I can tell the car is running is if I look at the tacho. Im still not sure what the issue was but the car runs perfect now so im going to run it in the tank from now on.