i use a 77 b250 sportsman for work (electrician) and I get 17-20 with it loaded down. of course i get that empty too. never changes unless i get ethynol or need a tune up

the truck has p235x75x15 tires (28 inches tall), per the sticker under the hood the axel ratio is a 3.21,, 4th gear is an overdrive.

I think I am close on guessing the 65 mph, never re-calibrated the speedo when the larger tires went on, found a site with info to do that

www.mymopar.com/speedometer.htm

i know i asked ya'll about my slant six gas mileage but would any of ya know how to get more mileage out of a 1999 mercury sable 24v dohc v6? shes gettin about 18 city right now and 23 hwy. i know shes supposed to get 20 city and 28 hwy....any clue?

Check out this site for newer cars http://ecomodder.com/forum/