I saw a question about tire size on one of the RV forums I monitor. About a dozen people replied. ALL of them ignored the importance of including both the “type” tire and the tire “load range.”
The initial question involved changing a “225/75R15” size tire. The poster didn’t provide information on what type tire (passenger [P], special trailer [ST] or light truck [LT]) he was talking about.
He and those providing answers also failed to provide what load range tire they were discussing (standard load [SL], extra load [XL], load range C or load range D).
I offered the following safety-related information.
- A 225/75R15ST is rated for 2,150# @ 50 psi if it is LR-C, and 2,540# @ 65 psi if it is LR-D.
- A P225/75R15 is rated 1,874# @ 35 psi for standard load, or 2,028# at 41 psi if the tire was rated “extra load”
- An LT225/75R15 LR-C is rated for 1,875# @ 50 psi, and 2,205# @ 65 psi if LR-D.
Whenever talking about tire size and load capacity, it is important to include the information on type tire and load range. Otherwise, you could end up with tire failures due to overload and/or under-inflation. You can see the range of possible inflation and load capacities above.
If you ever get involved in a discussion on tires, please be sure to include the CRITICAL information of type tire and load range
Roger Marble
MORE POSTS FROM ROGER ON TIRE SIZE
- Attention to detail is VERY important when it comes to tire size
- What do all those letters mean in the tire size?
- Can you change tire size or type on your RV?
- If I upsize my RV’s tires, can I lower their inflation?
- Is it illegal to change tire type or size on an RV?
*****
If you have tire questions, check out Roger’s posts on RVtravel.com. There are hundreds of posts covering everything to do with tires.
If you still have a question for Roger after searching the above posts, send your inquiries to him using the form below.
RVT1255
