I just remembered, my tires are Chapparall or something like that
I've heard that if you can keep the shifts below 2000 rpms they will do better.dave when you slow down to stop or something, do you coast, let off the gas while still in gear, or down shift? and what RPM do you shift at?
That really depends more on gearing than anything else. A f450-550 with 4.30s will do better than a F450 with 4.88 gears. I think a F450-550 with 4.30s & the right amount of power would do about as good as a F350 with 4.10 gears. But then again too it depends how the truck is configured.....single, super, crewcab...wheel base length, flatbed, dump truck, 5th wheel hauler....Does anyone know how much worse the f450-f550's get?
When the tire shop rotates my tires (free rotate & balance for the life of the tires ) they always air them up to 65lbs. That way the whole surface of tire contacts the road & rides good & wears evenly. They said they don't even bother going up to 80 unless your hauling something heavy.well, i just checked my E rated tires that call for 80 psi cold, and they were 55 psi. No wonder why my mileage is such crap. I'm getting 12-13 mpg in town being nice with a 2wd f350 cc. And the local gas station compressors will not fill my tires to more than 70 psi :doh:
I didn't buy 265 Mud radials because I was after MPG. In all truth though I don't notice much diffrence MPG wise in a 235 aired up vrs. a 265 except that the 265 rides ALOT better. The last owner with had a camper shell that sat flush with the cab roof & a stock exhaust with 235 A/T radials & said he normally saw 14mpg. I got it & straight piped it & pulled the camper shell off, installed a set of 265-75/16R mud radials & was regulary getting 16mpg when I drove it easy & 14mpg when I was harder on it in the summer.Yeah, but you'll have less rolling resistance with more air in them, thus resulting better fuel economy.