The decal on my door pillow shows my correct tire size as being 275/60R20. I recently ordered new tires from Amazon. I decided on LT tires because I pull a 5th RV. My original factory tires never seemed to have any problems hauling the load, it's just time for some new tires, and I decided I wanted the extra stoutness. When I did the search on Amazon for LT275/60R20, it came up with a pretty long list. I found a set of tires I liked and ordered them. I didn't notice until after they came in today, that they were the wrong size. They were one size narrower, LT265/60R20. I went back to Amazon and looked and they had slipped that tire into the list, and I missed it. Do I need to cough up the money and send them back, or would it be OK to run one size narrower?

 

Other than a slight impact to speedo accuracy, there shouldnt be any issues running that tire. Go here, click the "tire comparison" tab, and type in both tire sizes. You can see how slightly off your speedo will be. If you are otherwise happy, I wouldnt bother changing them.

EDIT: whoops, forgot the link.
https://tiresize.com/calculator/

 

Thank you sir. Go where? Did you intend to mention a link?

 

Try this one. There are dozens of sites like this for tire/wheel/offset comparison:

Rim & Tire Size Calculator

- Bob

 

That size is 10 mm narrower and 6 mm shorter. In American that's about 3/8" and 1/4". It will be 0.7% shorter than the stock size.

 

You are perfectly fine with that size. Use Forscan to correct the diameter so your speedo is accurate.

 

I would suspect it will be fine but you need to be sure that the narrower tire is OK on the rim. I believe that data is usually available somewhere. Also it will be a little smaller diameter than a 275.