Ford E450 Tire Size

Hi,

I thought I had to move to a wider rim for a wider tire.

Don,

Would you explain why you are considering a rim change just to go to a 245 tire that can, in that size and still on a 16 inch rim, handle nearly 2800 lbs (dually configuration) weight per tire with 80 lbs. of pressure??

Take a look at this typical Michelin tire chart for some of their 16 inch RV tires. Note that all four sizes there - 215, 225, 235, 245 - can fit on 6.50 or 7.00 inch rims. I think that the stock Ford E450 rims are 6.5 or 7.0 inches wide (click the "Specifications" tab):

http://www.michelinrvtires.com/michelinrv/tires-retreads/tireInfo.do?tread=XPS RIB

Also why do you prefer a wider tread footprint? I understand the need for a taller tire, but wider ... I'd like to hear what you say.

When I switched from 16" to 19.5" two major differences were noted. Handling, especially when loaded was wildly improved, like driving a different vehicle. Secondly tire life was increased, perhaps 200% over the 16's.

Ride comfort suffered. This was primarily due I feel to going from load range E to load range G. Well, you can't have-it-all.

The last BF Goodrich 235R X 16" load range E I cut apart had THREE plies plus the belts.

When I switched I had to take into consideration, speedometer error, and gear ratio changes. I ended up with a manual 4-speed preferring to take off in 1st gear (granny). Then a trip to the speedometer shop.

But, the 19.5's did not explode like the 16"'s tended to do (they were not overloaded).

Hi,

Did you go wider as well as 17.5 rims?

Do you have a ball park figure for the cost?

cal47 wrote:
Check out my signature,Rickson 17.5's with Toyo tires. Best mod I ever made. MH was stock from factory and almost over weight. Give Dan a Call at Rickson, great guy to help you out.

Check out my signature,Rickson 17.5's with Toyo tires. Best mod I ever made. MH was stock from factory and almost over weight. Give Dan a Call at Rickson, great guy to help you out.

Hi,

Can you define significant? My usual rate of travel is 78 kph (49 mph), because that is a "sweet spot" for mileage.

crankshop1000 wrote:
A significant increase in tire diameter will result in a significant decrease in braking power.

A significant increase in tire diameter will result in a significant decrease in braking power.

It's nice to have the extra margin. Michelin in the wider size has extra margin as well. The specs are not always higher, but their tires seem to outperform in Motorhome applications near the limit.

Jim

Hi Jim,

I'm still going with wider higher capacity tires. I'm not comfortable with the 225 and have been advised to jump up to 245.

When I talked to the Ford engineers for my 2001 they told me those shocks are designed to handle every permutation from a blank cutaway running unbuilt down the road to a cube van with fully loaded axles. They will work in an RV, but they are far, far from optimum. The rears are likely toast by now and maybe all 4. I'd go for some designed for the weight of the rear axle (beefy) and the likely lightly or medium loaded front end (softest I could find). The air bags will probably do more for your ride with better shocks in back.

After that, stock sized tires might even give you the ride you want.

Jim