I have a fast 2.0 on my 505 , I have the a/f ratios about half way between the min and max recommended settings right now, timing 34 total all in at 3000 , (91 OCTANE NON ALCOHOL DOG PISS" , still not done w/ it. Its getting way better than 6 mpg, haven't checked for sure, but it seems to get better mileage than my "new 440 4 speed dodge did , back in the day. I did have the total cruise timing out on the road at 50 , changed it to 45 , still messing w/ it in between rain storms ----which aint often around here this year !
I have the enrichment START UP setting 2 clicks richer than what is on the self tuning set up , need that for the tall intake I`m running , still have to give it one pedal before hitting the starter , to get it to start quickly , altho u aint supposed to have to do that .
Don't be afraid to lean it down a couple of clicks right off the bat , the self learning set up is rich / for safety reasons.
I had to go to a step hotter plug ------------ngk 6 . 3;73 rear gear w/ 29" tall tire out back , with a 3:91 , I`d run the tallest thing I could get under it for the street .----------Tell us what u come up with .