Community Forums

simply40 · 10-11-2015, 04:35 PM

I know this has been discussed (I did a search but no answer)so if moderators want to delete or move I understand.
I have a 30 foot 5th wheel, I have 3 ea Marathon ST225/75R15 tires rated D and 1 rated C. Should I buy a new D or will I be OK running 3@ 65lbs and 1@ 50lbs?
thanks

Mr_D · 10-11-2015, 04:42 PM

Get matching tires rated for the rig!

Texastbird · 10-12-2015, 10:00 AM

The rims should be marked on the back as to the maximum pressure they are rated for. Also make sure you have the right valve stems. It would be a bummer to have the correct tires and have a lower rated valve stem blow out. I've never seen it myself, but my tire guy says he has seen it more often than you think.

SkiSmuggs · 10-12-2015, 10:15 AM

Quote:

Originally Posted by simply40

I know this has been discussed (I did a search but no answer)so if moderators want to delete or move I understand.
I have a 30 foot 5th wheel, I have 3 ea Marathon ST225/75R15 tires rated D and 1 rated C. Should I buy a new D or will I be OK running 3@ 65lbs and 1@ 50lbs?
thanks

I would replace the C Load with D load to be safe. While weight may indicate the C is okay, I doubt running at different air pressures helps and RV builders tend to under build. I replaced my D rated with E rated and ran at 70-75 lbs. More capacity than the Ds at 65, but not as bouncy as 80 lbs.

FastEagle · 10-12-2015, 04:39 PM

Quote:

Originally Posted by simply40

I know this has been discussed (I did a search but no answer)so if moderators want to delete or move I understand.
I have a 30 foot 5th wheel, I have 3 ea Marathon ST225/75R15 tires rated D and 1 rated C. Should I buy a new D or will I be OK running 3@ 65lbs and 1@ 50lbs?
thanks

Depends on the trailer's OE tire size. Look on the tire placard, certification label or in the owner's manual.

simply40 · 10-14-2015, 09:07 PM

Quote:

Originally Posted by SkiSmuggs

I would replace the C Load with D load to be safe. While weight may indicate the C is okay, I doubt running at different air pressures helps and RV builders tend to under build. I replaced my D rated with E rated and ran at 70-75 lbs. More capacity than the Ds at 65, but not as bouncy as 80 lbs.

Thank you, I was in the limit with C but switched to a D and feel better about it.