Last summer, I had a custom 93 octane tune completed by Stratified for my FBO, IS20 GTI. Everything had been running great (very little KR under any conditions) but as the the weather turned cold (Eastern PA) and the winter gas mix arrived, I have been seeing quite a bit of KR on all 4 cylinders of up to -5, but intermittently. I tried splashing in 1-2 gallons of E85 and it cleaned it right up and all the plugs look like new and are gapped correctly, which leads me to the conclusion that it's the gas.
I had thought about ordering a top-up tune, but I really don't want to go through the trouble of logging and doing revisions again. My thought was that I could just order a 91 flash tune to give myself plenty of headroom on winter gas and I wouldn't lose much performance since my winter tires break loose in 3rd gear on my current tune. Then I can switch back to my 93 octane tune in the summer when I put the sticky tires back on. I'm looking for opinions or experiences with running a separate tune for winter gas; have you done it? what did you tune for? how bad was the winter gas where you live?
I had thought about ordering a top-up tune, but I really don't want to go through the trouble of logging and doing revisions again. My thought was that I could just order a 91 flash tune to give myself plenty of headroom on winter gas and I wouldn't lose much performance since my winter tires break loose in 3rd gear on my current tune. Then I can switch back to my 93 octane tune in the summer when I put the sticky tires back on. I'm looking for opinions or experiences with running a separate tune for winter gas; have you done it? what did you tune for? how bad was the winter gas where you live?