Ford Class C with 6 speed transmission
I see that the newer Fords with a V 10 have a six speed auto transmission. When did they replace the old 5 speed (I had a '99 with only a 4 speed) Would one expect to get better gas mileage with the n...
Forum Discussion
I think that I've improved my motorhome's V10 fuel economy over what is possible with it's 5-speed 5R110W transmission by retrofitting it with non-stock tires that are larger in diameter. Going to a larger diameter tire makes all gears "taller" in any vehicle for improved fuel economy when cruising.
Since our Class C motorhome is a relatively small one for it's E450 chassis, I don't need the extra pulling power that the E450's 4:56 ratio differential provides, so I may as well get some improved mileage through use of larger diameter tires.
An E350 chassis has a 4:12 rear differential ratio, so larger diameter tires on it under a motorhome might make it lug down on hills a bit.
Since our Class C motorhome is a relatively small one for it's E450 chassis, I don't need the extra pulling power that the E450's 4:56 ratio differential provides, so I may as well get some improved mileage through use of larger diameter tires.
An E350 chassis has a 4:12 rear differential ratio, so larger diameter tires on it under a motorhome might make it lug down on hills a bit.
