Tech Q&A: Andy Petree

February 8, 2001
5:58 PM EST (2258 GMT)

Q: Just what exactly do the teams fill the tires with? I thought it would be air, but my friend says something else. Brent Evans Villa Park, Ill.

A: We just use nitrogen. The Goodyear people fill them with just regular compressed air when we get them. The teams take the air out, just take the core out, drain the air out of them, and then put nitrogen in them, which is a little drier air. That's the only reason we do it is because it doesn't have as much moisture in it.

Q: Do NASCAR teams stagger the rear ends (tires) in race cars like they do with sprint cars? Shawn Holzapfel Hartstown, Pa.

A: No. The tire stagger is pre-set by Goodyear. The tires are identical size left and rights, and if there's one inch of stagger or 1.1 inches of stagger built in, that's what you've got. You can't change it.

Q: How wide are NASCAR Winston Cup Series tires? Does this ever vary? What about height? Beverly Grove Cincinnati, Ohio

A: There are slight variations when, say you go to a short track. Most of the tires would look the same width if you just looked at them. There are some slight differences in tread width. I think they go anywhere from like 9 to 11 (inches).

Q: I was wanting to know how much air pressure you run in Goodyear racing tires and is there a minimum or maximum? B. Heard Hobbs, N.M.

A: No, there is no minimum of maximum, you can run anything you want to. What limits that is whatever your heart will stand. If you want to run low air pressure, which a lot of times that makes a big difference, you can do that. We run as low as 12 pounds at some short tracks on the left side, to as high as 60 pounds on the right side on some of these superspeedways. There's a lot of in-betweens.

Q: I know that the lug nuts are glued to the rims for easier and faster tire changes in the pits. My question is this: To me it would seem that after the first one is tightened, the rest of the nuts would be pushed off by the lug ... How is this prevented? William Toole Hudson Falls, N.Y.

A: What it is is the stud itself, or part of it, has a half-an-inch turned down. It goes right through your threads. It gets to where the nut is sitting right on top of the stud. It doesn't have any threads right there, so when you get ready to push it on there, it doesn't fall off. It's just sitting there ready to go.