I got the maximum size for covering my Tahoe tires. (See image of my tire sidewall for exact size). Since we hardly ever drive the Tahoe unless it's pulling our trailer, it just sits in the sun & the side walls get sunburned and dry out long before the treads. Since these RV-towing quality tires are very expensive, I decided to get these covers to protect them like I protect my RV tires.I think for the money they are a good value. Unfortunately I am over stretching them to the max because my tires are so wide. As you can see I ripped a seam and repaired it with some gorilla tape. And another is also ripped and I'll be repairing it soon. I wish they made a larger size to deal with the super wide tires. But for now they are doing the job.