QuestionQUESTION: I currently have P265/70R16 tires on 8" rims. I want to replace them with LT245/75R16 tires. The circumference is within 1% but the 75 aspect tires are listed for 7" rims. Can I put them on the 8" rims?
ANSWER: Jay,
The allowable rim width range for an LT245/75R16 is 6 1/2" to 7 1/2" - so, No, you can not put them on 8" wide rims. If you do, the tire will dearch across the tread face. That will likely result in excessive wear on the shoulders of the tire, plus the tire will likely not track correctly, resulting in a vague feeling and be sensitive to the grooves and ruts in the road surface.
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QUESTION: Is there a chart or web site that lists the rim width ranges for the size of the tires? Thank you so much for your assistance.
ANSWER: Jay,
http://www.1010tires.com/TireSizeCalculator.asp
One of the outputs is rim width range.
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QUESTION: I apologize for digging deeper, however, after using the link you provided, how can a narrower 235 tire be mounted on an 8" rim (allowable rim width range 6" - 8") but the wider 245 cannot? Also, I researched some of your other excellent advice and found an answer you provided to David on 1-2-2009 whereby you state, "An LT245/75R16 load Range E ... with an approved rim width range from 6 1/2 to 8"." Is it possible that there is an error with the specifications for a 245 tire on the link or is there something special about a 245 tire that the 8" rim will cause the dearching?
Thank you again for this valuable information.
AnswerJay,
Good catch.
I always look these things up before I respond, and this was the place I looked it up when I responded to you.
However, I also use other sources, depending on where I am at the moment. When I use those other sources of information, I find a difference - and it's obvious this web site has an error in it.
I have helped these guys in the past - and I know they are using a lookup table, so I suspect that this one entry has an error in it and the others are OK.
So I have to amend my answer to the tires will fit on an 8" rim.
But that now brings up other issues that did not need to be discussed so long as my advice was negative - and that is load carrying capacity.
A P265/70R16 has a load carrying capacity of 2403# at 35 psi - and since this is used on a light truck, it has to be derated to 2185#.
You didn't tell me what vehicle this is going on, so I couldn't look up the inflation pressure listed on the vehicle tire placard, but you should find it to see if it is different than 35 psi. If so, then what I am about to write is incorrect.
In order to carry the load as a P265/70R16 can at 35 psi, an LT245/75R16 needs to use 50 psi. This is why I do not recommend replacing P metric tires with LT metric tires.
