Tires: Winter Tires for a S-10, gmc sonoma zr2, gmc sonoma

Question
Hello Barry
What follows is an e-mail from my son. He (and I) believe a narrower winter tire will increase traction. Is it possible to find a light truck winter tire of similar OEM diameter but narrower tread width in the same(or differing)rim size?
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Hey Dad here is the information about my truck/ tire size

01 GMC Sonoma (zr2)
4.3 litre V6 4x4

tire size :31x10.50 R 15

If you are looking for tires .... i would like something narrower, loosing a couple inches on the diameter of the tire would be a sacrifice I'm willing to make if the tire is narrower. Good winter tires would be nice instead of an all season mud and snow tire.

Answer
Raoul,

The first step is for your son to find the vehicle placard.  It lists the original tire size and the proper pressure for that size.  It is usually located on a doorpost or in the glove box.  I can guarrantee it won't say 31X10.50R15LT.

Then the next step is to read up about tire sizing on Tire Rack's web site:

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=46

Then that should  get you where you need to be to get started on this process.