Replacing tires with wider tires.

Hi,

I upgraded to wider and taller tires. If you have duals it requires new rims so the offset is correct. It improved mileage and handling and got me into a "safe zone" for tire carrying capacity. I would do it again.

Make sure there is fender clearance.

Get RV rated tires not truck tires. The size of a wider tire will not help the steering or handling. That is done through having front end suspension and control components that are not worn out. A loose control arm will still be a problem not matter what width the tires are. Then most wider tires are lower as the 80 v the 70 v the 60 v the 40 v the 30 just get you lower the ground. Plus the wheel is also designed for the tire, and will not work with some wide tire sizes. Make sure the sway bar bushings are replaced with neoprene as rubber ones don't last long and are softer. Shocks and spring and air bags if you have them all need to be of high quality for best ride. The wheel bearings also need to be checked for flat spots and the damage they may have done to the spindle is the scored it. Then the steering box may be shot too. If it's the wider look you want, don't go there, as your vehicle was designed for a specific tire size and rating for the suspension and road clearance and level of the front to back stance. Of course the rear suspension may also be incorrect due to sagging spring and sway bar bushings and shocks being worn out.

In case and I say in case you do not make the change I am getting pretty good service from Samson tires which I got from Chicago Tire via EBAY.
http://www.ebay.com/itm/6-tires-8r19-5-GL283A-All-Position-12-PR-truck-RV-tire-8x19-5-8-19-5-8195-/131226396578?pt=Motors_Car_Truck_Tires&hash=item1e8db3e7a2&vxp=mtr Make an offer at $1000.00 for all six delivered. The ones I got have all been fairly recent manufacture date.
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The actual change has been discussed to death already and you can pick through the threads at
http://forums.motorhomemagazine.com/index.cfm/fuseaction/search/parms/sw%7B8r%7D|km%7Bexact%7D|kl%7Bm%7D|fm%7B%7D|pd%7B365%7D|ma%7B%7D/sr/1.cfm

Whichever you go with find a place that actually balances the tire not throw in those darn packets

I have a 1995 winnebago and went with 245/70 r19.5 up front and stayed with 8r19.5 in the rear. They are the same height. Handling and ride is a lot better.Running 95psi up front and 90 psi in rear.

Moved from Forum Technical Support

I did it on mine. Would not do it again because I gained RPM on the engine thus going from 8.75mpg down to 8.0mpg because of the higher engine RPM. They ride great but I don't like the trade off. Plus the engine compartment is louder. I did not notice any better handling.

A 1993 will have overdrive...the slight RPM increase might help.

A 225/70 is a direct replacement for an 8R19.5 tire, but an inch or so shorter. A 245/70 is the same diameter and should work in front, but may require new wheels in back. (Duals may rub.)

pianotuna wrote:
Hi,

I upgraded to wider and taller tires. If you have duals it requires new rims so the offset is correct. It improved mileage and handling and got me into a "safe zone" for tire carrying capacity. I would do it again.

Make sure there is fender clearance.

I had 8R-19.5s on a 1993 Southwind and switched to 225-70 x 19.5 Bridgestones and never replaced anything.

Ive never seen a P30 yet that a direct swap from 8R's to 22-70's couldnt be easily accomplished

I have a question .. if one changes wheel and tire size even one inch in diameter, doesn't the speedometer read incorrectly both in MPH and mileasge?

If so, can that we adjusted according at the speedo end??

:h

Since the speed is determined by the turning of the front driver side,(left),on the P 30 the faster the wheel turns the higher speed it will read. If height is same no problem, but if smaller the wheel turns faster, if higher it turns slower. Vertical weight is distributed on the profile of the tire, and lateral movement is controlled by the strength of the sidewall, which is under more stress with wider tires, as road surface is greater. They may ride softer, but that's due to there weakness. This is assuming the tires are the same rating for weight. You have to understand the tire is designed for the vehicle and any changes are possibly not top design specifications and if below are not recommended and above may change many safety factors.