newb tire question

[lilchinoboy03]

ok i know that rims are measured by 15'',17'',18''....and so on...and tires are measured by 7...7.5....8...wats the units for that? and wats all this 225/50/16 stuff????? sorry....newb to rims and wheels....

[StreetFighter]

Go to tirerack.com and they will tell you what those numbers are.

225/50/16

225 means the width of the tire, 50 is the height of the tire, and 16 is the dimension of the tire. In order to get the height of the tire, 50 is the percentage of 225. I hope that answers your question.

[cooltoy2000]

225 is the width of the tire in mm.
50 (the series) is the ratio of the side wall to the width of the tire in percent (50% of 225 is the sidewall height).
16 is the rim diameter in inches.
7, 7.5, 8 and etcetra are offset numbers. Offset means where the mounting point is located in the rim, whether it be closer to the front or the back of the rim. It determines how far the rim will stick out off or how deep it wil sit in the wheel well.

[lilchinoboy03]

alright...cool..thanx guys for the info

[vvtlikick]

I'll use the most common Celica GT-S tire and wheel size as an example.

Tires: 205/50-16

Tire is 205mm wide, sidewall is 102.5mm (50% of 205mm), wheel diameter should be 16in


Wheels: 15in × 6.5 in, +39mm offset, 57mm centerbore (I think :gap:), 5×100mm bolt pattern

Diameter of tire mounting surface is 16 inches, width of tire mounting surface is 6.5 inches.

Offset is +39mm, this means that, when mounted on the car, the wheel sits 39mm inboard of a +0mm offset wheel.

Centerbore (57mm?) is the diameter of the center hole on the back of the wheel. This must match the hub's protrusion, since this is how the vehicle's weight is supported. Aftermarket wheels will usually use a extralarge centerbore and then add hub-centric rings in the hole to make up the specific difference for each specific car.

The bolt pattern is 5×100mm. This means there are 5 lugs, with 100mm between non-adjacent lugs. A wheel with a incorrect bolt pattern won't work. But some wheels have multiple patterns.



As for aftermarket wheels, they must match the bolt pattern and centerbore. If the centerbore is too large, it can be corrected by the aforementioned hub-centric rings. The offset should also be close to stock (for the Celica, I'd probably only consider using +35mm to +42mm).

As for tires they must match the wheel's diameter, and they must be the appropriate width for the wheel's width. The best way to determine the appropriate width is to consult the tire manufacturer. Manufacturer recommended width data is widely and freely available (check any website).

Also, since tires are flexible, there is almost always a range of allowable values. If I recall correctly, the stock 205/50-16 Celica GT-S tires can be mounted on a wheel from 6.5in to 7.5in (or 8in?) wide.

[lilchinoboy03]

wow alright thats good ish right there...more than enough facts...so when u say wheel do u mean rims? or somethin else?

[cooltoy2000]

Yes.