tire size for 79 super spare

[sourgrapes]

I have four new tires on my car and they are 165 R15 86 T.

I am looking for a used tire for a spare and the fellow at the shop told me that I am missing some numbers. Is there a trick to sizing a tire?

That's all I can see on it.

[ANSAracingb]

I thought it is a full size spare? I have a standard but that's what fits in my spare wheel well.

If so then you should be looking for a 165/80R15. The 86T has to do with the load index and speed rating.

[vw_hank]

Yes its A full size spare,, 165/80r15

[sourgrapes]

Thanks guys. That's exactly what I needed.