Tire sizing,....

[1RADNSX]

Ok,...I'm not the sharpest knife in the drawer so somebody clue me on the tire spec. info. for instance,..I have 285-35 ZR-18 tires on the rear. I believe the 18 is for the height. Help me with the 285-35,..One is something to do with height???

 

[Shumdit]

The 10 is actually the wheel diameter in your number, and I would find it very unlikely 10 would be that number unless you drive a Ford Festiva with a Rally kit!
The 285 is the cross section (width) of the tires in mm, and the 30 is the sidewall height (approx. 30% of the 285 mm), so a 305/30 tire would be taller than a 285, since 305x.30 is more than 285x.30.

 

[redshift]

I think it works like this...

10 is the wheel diameter in inches.
285 is the width in mm
35 is the aspect percentage of the width (height/distance between outer diameter of the wheel to the outer diameter of the tire) - tells you how tall your tire is

so this tire is on a 10 inch wheel, it is 11.2" wide (285mm), and it is 3.9" (.35 * 285mm) tall across the aspect.

 

[1RADNSX]

I entered incorrect tire size on first post, which I have since corrected. I still have fuzzy understanding. I want to start looking to buy wheels and am not sure if I should stay with what I have. 285-35zr-18 on rear and 235-40zr-17 on the front. It's tight, but seems to work,...

 

[Shumdit]

I entered incorrect tire size on first post, which I have since corrected. I still have fuzzy understanding. I want to start looking to buy wheels and am not sure if I should stay with what I have. 285-35zr-18 on rear and 235-40zr-17 on the front. It's tight, but seems to work,...

235 will rub I am pretty certain if the wheels you are using are offset correctly. 285 will be close too. A few others here can give you better info, especially if you know the wheel width/offset and model.

 

[1RADNSX]

Shumdit,..The 285's on the rear seem to be fine even tho they are pretty tight, I don't see any signs of rub. The front is a differant story. It turns out the bolts on the lower end of my Koni struts were way loose and when I hit a good bump on the freeway the camber was enough to cause the edge of the tires to grab the front fenders on both sides. Minor, but they need to be rolled back a little. I have since corrected that as well as tie rod work on passenger side. Other than that little hiccup the only thing I notice is on a tight turn they do rub a little on the inside of the plastic wheel well liner. Anybody out there know where to get replacement plastic wheel wells?

 

[Shumdit]

Shumdit,..The 285's on the rear seem to be fine even tho they are pretty tight, I don't see any signs of rub. The front is a differant story. It turns out the bolts on the lower end of my Koni struts were way loose and when I hit a good bump on the freeway the camber was enough to cause the edge of the tires to grab the front fenders on both sides. Minor, but they need to be rolled back a little. I have since corrected that as well as tie rod work on passenger side. Other than that little hiccup the only thing I notice is on a tight turn they do rub a little on the inside of the plastic wheel well liner. Anybody out there know where to get replacement plastic wheel wells?

Dealer only I think

 

[RP-Motorsports]

we run 235-40-17 on the track on a stock front end with Eibach/Koni's, at a +43mm offset rub free. :wink:

 

[1RADNSX]

Thanx RP-Motorsports,..I'll have a Tire shop check out the offset to see if it's at 43mm. If it's less than that, could be the problem,...Anybody out there have a tire shop recommendation for Marin County? Thanx in advance,..Steve,..

 

[BioBanker]

You have the fender liner in there RP?