Tire size confusion

[coolvanilla]

I have 15x6 smoothie rims and the tires on it now are 195/65/15. My question is if can I put a wider tire on and if so what size would fit and will change how the car handles. I had white walls that size, they wore up so to save money I went back to black walls. Now I am thinking of going back to white walls.

Thanks

[FlowRW]

I'm assuming since you had 15's then you have rear drum brakes and no traction control and maybe no ABS. Are you planning on using the same rims, the 15x6? If so, you can put tires on there as long as they are approved for rims 6 inches wide. Those 6" wide rims will limit the size of tire you can safely use.

The original diameter of the stock tire is right at 25" and you should stick pretty close to that, no more than 3/4 an inch either way mainly for your speedometer and in case you have ABS.

[robinh]

Depends on a couple of things - aspect ratio (width to height) and the tire width itself. Tires are measured in millimeters, so if you say you have a 195, that is 195 mm wide, or approximately 7.7" wide. Now as far as tire height goes, you measure from the bead to the highest point on the tire to get the height. The aspect ratio you showed for your tires was a 65, that means that the height of the tire is 65% of the width so 195 x .65 = 126.75 mm or 5" tall. So you have to remember, as you widen your tire, you must be aware of your aspect ratio so that you don't end up with a fat tire that's too tall for your fender wells.

Now, the other major issue on the PT's is the front tires - width here is an issue but mainly for your wheels, rather than your tires. If your wheels get too wide, they can scrape the outside facing of the calipers. If the tires get too wide, they can rub on either the fender well wall, or on the front strut. Mind you, that would have to be one hell of a wide tire to do that.

Now the last concern, and the one you really need to pay the most attention to, is that aspect ratio. You can put a 225 tire on a 15x6 rim. Yes, you can. However, with a small wheel like that and a wide tire on it like that, your tire will not have a flat area for road surface contact. The contact patch is very important as it affects the traction you will get with your tires. So, a narrow wheel will not be good with a wide tire.

If you take a look at some of the older rides, you'll find that many of them originally ran 6" wide wheels. Take the Jag XJ6 for example - that car came factory with 15x6 and 205/70's for tires! With that width and height, probably a nice riding tire. Now I looked up some factory specs and many manufacturers state that a 235 width is the widest tire you should put on a 15x6 rim. That being said, at 235 it's going to balloon on that wheel and look kind of silly, along with reducing your contact patch, therefor reducing the friction and controllability when it's on the car.

You can ask many tire dealers, just give them a call and ask their advice. Personally, I'd call Discount Tire and ask their advice, they are pretty straight forward when it comes to tire advice and pretty trustworthy. They also happen to have some great prices (no, I'm not affiliated with them in any way!) too. My suggestion for a 15x6 wheel would be, max, a 215/70x15. Just my suggestion, others may have more to say.

[FlowRW]

You can go to Discount Tire but if you want to search from the comfort of your home, www.TireRack.com is a great source. By putting in your car type, it will give you the stock size. From that point you can search the various tires that will fit on 6 inch rims and keep the same diameter closer to 25 inches. A 225/50 will keep a close 25 inch diameter and is about the widest tire you should put on a 6 inch rim. And from experience, that 225/50 will only allow you to get a finger between the inside of the tire and the shock absorber in the rear. It won't scrape the fender. It is pushing the limits though. Those of us with 4 wheel disc brakes, ABS and traction control, it's terribly important to stay within that 3/4 inch either way of the diameter of the original tire.

[electricbluegt]

I'll add that the rim width becomes less of an issue with a taller tire than with a lower profile tire. You have much more sidewall to work with and the sidewall is deflected less with a tall tire. My GT uses 205/50 tires stock. I have 225/45 on it now. A lot of sites on the web recommended a minimum rim width of 7" for that tire size, but mine are 6" wide. When I first replaced my OEM tires, I went with a 215/45 because of all the comments about rim width. It turned out that the particular tires (Hankook) I put on were much narrower than the stock tires. I had to go to a 225 width just to get back to normal. It just depends on the mold of the particular tire you're looking at.

Moral of the story, go find a tire size that keeps the overall diameter the same and as long as you aren't trying to go extremely wide, any tire you pick should be fine.

[ptpanel]

Also because you say you want to go back to WW You need to decide how wide you want your WW to be. The smaller the sidewall the rougher the ride. Diamond Back www.dbtires.com has a great selection of WW. A little pricy but they have a good reputation. I am not sure but I think they can put their WW on any tire. (brand name) I got 195/65/15, that is the widest WW I could find. Hope this helps.

[coolvanilla]

I thank all of you for your input. As with the replies you can see why I was so confused with tire size. The white walls I previous had on my PT were from DB tires, although back then they were 160.00 and now about 200.00. I do have drum brakes on the rear and no traction control. It was a standard Touring Edition when I bought it in 2005. The white walls were 2 1/4" wide which looked great. I did the search on Tire Rack and it only came up with the size I have on the car now.

If I'm correct I could look for a WW tire which is close to 25" and will fit a 6" rim. PTPANEL you stayed with the original size. Did you consider a wider tire at all? I'm sure you have the Diamond Back Fury on your PT.

OK, at Diamond Back they have 205/65R/15 white walls which are 25 1/2". Do these seem acceptable?

[ptpanel]

Yes I do have the Fury's. I had to get 15 because I couldn't find anyone that had 16" Cruiser Motor Sport has 16 advertised now but don't know about availability? The size I have are the widest THEY (DB) recommended for the 6" rim. If perfect I would have wider rims and tires but you can only get what is on the market. Hope this helps you decide.