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Tires/tire size fit


Hey Barry, I bought an old 5th wheel RV sitting out on a ranch in west Texas. It has 4 rotten 235/75- 15 tires on it. I need to move it a short distance. I want to take the good used 205/75 15 ties off my utility trailer, put them on the RV, and get new tires for the utility trailer which I use a lot on the road. Will the 205 tires fit the wheel with the 235 tires? thanks, Richard


First, you should plan on replacing the tires on the 5th wheel at some point in time - unless you are planning to completely take it out of service.

Second, the question you ask has some missing information - the width of the wheels on the 5th wheel.

A 235/75R15 has an allowable rim width of 6" to 8".  A 205/75R15 has an allowable rim width range of 5" to 7".  There is some overlap.  

But one of the questions will be :  Has the 205 taken such a set that the tire can not be made to take air during the mounting process?  Don't know the answer to that one.  You just need to be aware that it is a possibility.

And be very careful doing this.  A "short distance" should be confined to a few miles at slow speeds (Say under 30 mph).


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Barry Smith


I have over 30 years experience in the design, manufacturing, and testing of tires. I have served as the technical advisor to the "800" number. I have authored or co-authored many publications - usually without credit. I can answer almost any technical question, but please don`t ask me to compare brands. I probably have prejudices because of my work experience.


Member SAE (Society of Automotive Engineers) Member Tire Society (Tire Technical Organization) SCCA Regional Competiton License holder Authored many training manuals on tires, their care and use.

SAE (Society of Automotive Engineers) SCCA (Sports Car Club of America) Tire Society

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I am a graduate of the University of Dayton, Dayton, OH - BME, 1971 I attended graduate school at the University of Akron - but did not complete my PhD - something I regret.

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