I'm really unsure if I should go 4.56 or 4.88 on my 2012 3.6 auto (w5a580). I live at 1200ft, drive my jeep as a DD, mild offroading (overland) a couple times a year (ocassionally at 5000ft), but highway speed limit is 80mph and the view is non-existent, so driving 85 is ideal for my sanity. I tried using the RPM calculator with trans ratio of 0.83 (got this OD ratio on interwebs somewhere) and get a RPM of 3353 at 85 with 4.88 and RPM of 3133 at 85 with 4.56. I know it's only 250rpm difference, but when nearing 50% of readline it seems high to be running engine at 3353 for hours on end. I don't tow, but if I were to it would be two or three dirt bikes on a small trailer (maybe 1.0-1.2k lbs?) And that would be once maybe twice a year and I'd likely keep at 75-80mph pulling anything. Your thoughts?