Community Forums

Mdhcols · 04-15-2014, 05:57 PM

Hi all. Buying first set of tires on first coach I just bought last week. The load ratings have me confused. Maybe someone can set me straight. The coach is a 37 ft allegro bus with freightliner & Cat. The GFAR is 10,410. The GRAR is 17,000 and GCWR is 32,410. I thought I needed 275 /80R/22.5 with load rating H. Getting xza3's. However, they are apparently in short supply. The dealer has the tire in a G Load rating and says they will work fine. The Michelin tire site says at 110 lbs (max), the maximum sidewall weight for the G tire is 6175 lbs on the single and 11,350 on the end of the axle with duals. If I read right, both specs exceed the max weight the chassis can handle, but the front is much closer. The former owner ran at 100 lbs on front which reduces max sidewall weight to 5780. So with all of this, I am trying to decide if the G rate works and I am getting totally confused. Am I making it too hard?

brobox · 04-15-2014, 06:03 PM

You are not making it to hard, the dealer is trying to sell what he can get. If you weight calls for H rating, then that is what you need. What load range are currently on the MH. Also call Tiffin and see what is required.

Mdhcols · 04-15-2014, 06:09 PM

The coach has XZA1's , 10 yrs old and scary. H rating. I have a ton of original tiffin stuff but don't see the tire info required.

Mdhcols · 04-15-2014, 06:20 PM

The coach has XZA1's , 10 yrs old and scary. H rating. I have a ton of original tiffin stuff but don't see the tire info required.

brobox · 04-15-2014, 06:48 PM

If the existing tires are load range H then that is a good clue what is required for that coach. You don't have the year of your coach listed (it really helps) but if they are the original tires, then Tiffin has already answered the question of what load range is required.

Ray,IN · 04-15-2014, 08:25 PM

What brobox said! Lighter tires/less load range, means you'll have to run them at maximum pressure and maximum load. That is what all the complaining about ST trailer tire failures is about.

Mdhcols · 04-15-2014, 09:02 PM

It is a 2000, 3 slide . I think I will play it safe and wait until the H tires come in. One unnecessary flat would ruin my day......... The ones on it were 2004 so not original. I would rather have more sidewalk strength than I need , not pushing the envelope. As soon as we get it pm'd and loaded for FT, I will have
Freightliner weigh all four corners to satisfy myself.

Thank you.
Mike and Jennifer heading out in May. Going to work our way slowly from Phoenix to Northern Virginia........some shakedown trip.

gruelens · 04-15-2014, 11:48 PM

You are doing the right thing by insisting on H rated tires, they have two more plies than a G tire. Shame on that dealer for telling you otherwise only because he can make a quick sale. Be sure to tell them no deal unless the date codes are less than ____ months old. You fill in the blank with what number you are willing to accept as new tires. Remember RV tires age out before they wear out. All the best!