Ply ratings of tires

[mtnman1989]

I have a 1994 Fleetwood 30 foot P30 motorhome. It has 8r 19.5 tires on it and I need to replace them. I found a great buy on some 225 70R 19.5 tires but they are 10 ply tires? Has anyone ran any 10 ply tires on a P30 chassis?
mtnman

[mike_brez]

darsben wrote:

mtnman1989 wrote:
I have a 1994 Fleetwood 30 foot P30 motorhome. It has 8r 19.5 tires on it and I need to replace them. I found a great buy on some 225 70R 19.5 tires but they are 10 ply tires? Has anyone ran any 10 ply tires on a P30 chassis?
mtnman

How old are the great buy tires?

6 12 ply are $1000.00 which is what I run
see them here

Samson's?

[parkmanaa]

Two concerns: I have a 1997 P30 chassis. I recently replaced the 6 tires with 22570R19.5 LRF. Max. load at 95PSI. Weighed the vehicle and find, allowing about 5% safety margin, 75PSI front/rear is a good pressure for me.
Don't like to have tires that I need to keep at, or near the max. PSI.
Don't know what max PSI/max load rating is for 10PR tires, but you may find you need to constantly run at max. to carry your MH.
Also, I would strongly consider replacing those narrow 8R19.5's with the 22570R19.5's. In most cases cost is almost identical, but you will like the look and feel of driving on the low-profile, wider tire.
Finally, be careful of Chinese-made tires.
My recommendation, and have bought 2 sets of tires thru them in last 90 days, is simpletire.com. Very professional, excellent service.
Good luck.

[J-Rooster]

I buy all my tires that have high sidewall ratings!

[Hikerdogs]

Here's a scale of "ply" ratings with the equivalent load "ratings".

Ply Rating/Load Range: 2/A 4/B 6/C 8/D 10/E 12/F 14/G 16/H 18/J 20/L

Keep in mind the original ply ratings were done when tires used cotton. Later when nylon was introduced it was common to see ratings like 2Ply/4Ply rating since nylon was much stronger than cotton.

Here's a link to a good explanation from STTC Tire Service:
http://www.sttc.com/resources/tire-info/ply-rating

[darsben]

mtnman1989 wrote:
I have a 1994 Fleetwood 30 foot P30 motorhome. It has 8r 19.5 tires on it and I need to replace them. I found a great buy on some 225 70R 19.5 tires but they are 10 ply tires? Has anyone ran any 10 ply tires on a P30 chassis?
mtnman

How old are the great buy tires?

6 12 ply are $1000.00 which is what I run
see them here

[tderonne]

From Roger Marbles rvtiresafety.com:

Buddy Light said "I like RV tires with more plies".
Well Buddy you may not realize but "Ply Rating" is an old term that is based on an "equivalent strength" and not on the actual number of Ply or layers of reinforcement. You can read the material list of what is actually in your tires as it is molded on the tire sidewalls. It may say something like "Sidewall 2 Ply Polyester, Tread 2 ply Polyester + 2 ply Steel". If you have a large RV with 22.5 wheel diameter you may be surprised to learn the sidewall of many of these tires has only one Ply of Steel in the sidewall with an additional 3 or 4 Ply of Steel in the Tread area. These tires may have a "Ply Rating" of 12 or 14 but in reality there is only 1 ply in the tire.

[mtnman1989]

midnightsadie
What kind of motorhome do you have the 10 ply tires on?
mtnman

[donfrump]

wolfe10 wrote:
Comparing load ratings is more accurate than ply ratings on today's tires.

yes but generally the higher the ply rating the larger the load rating

(eg) a 2257019.5 mich 8 ply will have a lower load rate than the same tire in 10 ply

[wolfe10]

Comparing load ratings is more accurate than ply ratings on today's tires.

[midnightsadie]

my mh has 10 ply and no problems, IF there good brand? sounds like a deal.

[donfrump]

mtnman1989 wrote:
I have a 1994 Fleetwood 30 foot P30 motorhome. It has 8r 19.5 tires on it and I need to replace them. I found a great buy on some 225 70R 19.5 tires but they are 10 ply tires? Has anyone ran any 10 ply tires on a P30 chassis?
mtnman

Ride will stiffen for sure but depends on what air pressure you run at. Definately safer especially if one tends to overload(most people do)