Tire ply

[3dhunt]

My ‘07 HR Admiral 30 fsf came with 245/70x19.5 tires and a ply rating F. The previous owner changed to a G rated tire when he changed them. Is there any benefit to this or can I go back to the original ply set by the factory. We don’t tow and never load heavy, don’t carry water and usually dump tanks before we leave camp. Money isn’t the concern but wanted opinion on this. Am I sacrificing safety for ride quality?

[l1v3fr33ord1]

Dan-

The Ford 2007 Body Builder Layout Book says this about wheels and tires for the F-53 (link here):

WHEELS AND TIRES

1. The 245/70Rx19.5F (18,000 lb, 20,500 lb and
22,000 lb GVWR) and the 225/70Rx19.5F (15,700
lb GVWR) are the only tires approved for the
19.5" steel wheels F-Super Duty Class A Motor
Home Chassis (F53).

2. The 235/80R22.5 XRV LRG Michelin tire (22,000 lb
GVWR) is the only tire approved for the 22.5"
aluminum/steel wheels.

The placard to the left of the driver's seat should agree with this.

I'm the kind of person who likes to follow the factory specs, if possible (less second-guessing that way). However, you may find you can no longer buy tires this size in Load Range F. For example, a recent Michelin RV tire brochure (link here) shows just one model tire in 245/70R19.5, the XZE, and it's listed as Load Range H. A search shows a couple other manufacturer's tires this size in Load Range G.

[Gary RVRoamer]

The G-rated tire can be inflated to higher pressures than the F and thus can handle additional weight, but that's of no value if you don't need extra weight-carrying capacity to begin with. If you compare F & G rated tires in a load-inflation table, you will see that they are usually identical up to the max the F can do.


The only reason to move up to G vs F would be if your loaded weight put you right at the upper limit for the F tire. Or if the actual loaded weight exceeded the F rating. I doubt either is the case with your coach unless you are overloaded to begin with. The OEM tires were adequate for the coach GVWR and GAWRs as it was built.


So save yourself a few $ and go back to the OEM F-load range tires. And get the coach weighed so you know how much psi those tires actually need.

[theoldwizard]

Ply ratings and letter ratings are very "old school". Go by the actual weight rating on the tire sidewall.

[153stars]

I would consider the easier tire to get on the road if needed as well . Some owners go up a letter and run lower pressure to match load charts and say it can give better ride than lesser letter
tire at near max inflation. Just passing what I have read here no real experience swapping up.

[Sweetbriar]

For me G tires were easier to find locally than F unless I willing to wait for a set to be ordered and shipped. I can't recall if there was much of a cost difference also. No gain of capacity also as either weight class tire has much more capacity than the axles on my 18K lbs F53 chassis.

[Mudfrog]

I decided to replace the front two F rated 19.5s about 7 years ago. The shop didn't have F's so they installed G's. No matter what pressure I tried, the ride on the new tires was too firm. The whole rig was jarred by every little bump in the road. It could have just been the tire brand (Sailun) but needless to say, I got rid of them and replaced all 6 with F's less than a year later.