I'm a firm beleiver in using my tools to tune my parts, timing light, wide ban or time slips with my weather station. That being said I will enrich the mixture until the car slows down and then go the other way until it starts to slow down agian All changes made on the SAME DAY Same thing on timing but retard it one or two degrees max at a time first until it starts to slow down and then advance it a little bit, 1 or 2 dgrees, at a time until it starts to not like that also I'll normally run the least amount of timing and the smallest jets that are safe (regardless of fuel type) and leave it alone unless the density altitude changes more than 1000 FT. from that tuning location I'm seeing that the local pump E 85 fuel doesn't really care as much on the density altitude changes from morning until late afternoon like the pump gas and race gas did