Here's one for you. I had my G60 mapped at Stealth on about the coldest day of the year last winter. I also ran it on the rollers at SRR a couple of days later (when all was still very cold). When I came to run it on the SRR rollers a few weeks ago (after changing my exhaust) it was running very rich. To me this wasn't a huge surprise, but am I right in thinking that given the differences in ambient air temp and pressure this would be reflected in differences in rich or lean AFR readings? If so does that mean a better compromise would be a 'spring' or autumn' tune, as I'm thinking of getting it retuned once I have the 65mm pulley.