Wheel size upgrade.
My (new/old) 79 Holiday Rambler 27 is still sitting on 16.5 bias ply tires (all 6 less than a year old). I intend to budget for 6 radial tires to replace them (better ride and improve fuel economy). ...
Forum Discussion
pianotuna wrote:
Hi,
I went from 225/75R16 to 235/85R16. This required a wider offset for the rear dual wheels. I bought all new wheels. It increased the weight allowance for the tires which was a nice side benefit--and mileage is a little better (perhaps 5%)
It did give me more ground clearance by about 1 1/8 inches.
Outstanding! You did the right thing to accomplish three improvements at the same time. You also accomplished a 4th thing - you reduced tread wear somewhat - less revolutions per mile means that each molecule of tread rubber contacts the road surface less times per mile ;) .
I did almost the same thing so as to improve mileage, ground clearance, tire wear, and rear dual cooling while at the same time not having to buy new rims. I went to a 215/85/16R tire but stayed with the stock 16" rims. A 215/85/16R tire is actually taller (a larger diameter) than the stock E350/E450 225/75/16R tire. The 215/85 tire is a bit narrower so spacing between the rear duals is actually a little wider for better sidewall cooling when traveling in high summer temperatures. Both the stock tires and the new 215 tires were Load Range E, so I did not improve weight allowance.
IMHO, stock Ford (and Chevy, too) based Class C motorhomes are too low to the ground for the widest range of camping situations because these chassis were probably designed as a delivery van for easy access when loading and unloading on hard surface roads. Their fender well and front suspension steering spacings are plenty generous enough for 16 inch tires of a larger diameter than that of 225/75/16R tires.
