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Azzazzyn
03-30-2006, 11:27 PM
Hey, I have my 17's sitting right here, tireless. I want to get soem cheap tires for now, cuz i'm not worried about these rims, they're just for looks atm. anyway, tire size confuses me, can anyone point me into the direction to understanding or enlighten me themselves?

T-spoon
03-31-2006, 12:32 AM
Dunno which part you're not sure on, so don't get mad if I'm telling you basics you know.

Example tire: 215/50/15

First number - 215 = width of the tire.
Second number - 50 = sidewall height as a percent of width, in this case, 50% of 215.
Third number - 15 = inside diameter=wheel diameter, so 15 inch wheel

You want a total diameter (outside of tire to outside of tire) that isn't different than what it is with the stock wheels and tires. There are size calculaters all over the net that will tell you what will retain that stock total diameter. If you change it, your speedo reads less accurately.

That answer it, or did I miss what you were asking?

Morwan
03-31-2006, 12:35 AM
Let me explain tire code first:

205/50/R17

205 -Width of the tire is 205 mm
50 - the height of the sidewall relative to the width. 50 is 50% of the height, so they're 102.5 mm tall.
R - Radial tire
17 - Fits 17" wheels


So the only real important things are that the first number and the last number work with your wheels. You probably know you need 17" tires, but I need to know the width of your wheels before I can tell you what sizes would work.

T-spoon
03-31-2006, 12:48 AM
Let me explain tire code first:

205/50/R17

205 -Width of the tire is 205 mm
50 - the height of the sidewall relative to the width. 50 is 50% of the height, so they're 102.5 mm tall.
R - Radial tire
17 - Fits 17" wheels


So the only real important things are that the first number and the last number work with your wheels. You probably know you need 17" tires, but I need to know the width of your wheels before I can tell you what sizes would work.

Taking time to actually do the math = lose :hehe:

Morwan
03-31-2006, 12:52 AM
Dividing 205 by 2 isn't that hard.

T-spoon
03-31-2006, 12:55 AM
Dividing 205 by 2 isn't that hard.

:squint: It was a joke, man.....

Azzazzyn
03-31-2006, 01:36 AM
how do i find the width of the rim? all i can tell you is its +40 offset, c/hole is 73.1 pcd is 100 and 114.3

Azzazzyn
03-31-2006, 01:43 AM
i know 205 isn't great, but not looking for performance really. 205/40r-17 80h bsw wtf that mean exactly?

Morwan
03-31-2006, 02:49 AM
I have no idea what bsw means, but 80h is the load rating.

Your wheels are probably 17x7 (7" wide)... 205's should be fine.

Galcobar
03-31-2006, 05:13 AM
BSW -- Black side wall

Refers to the lettering on the sidewall and whether it has a white strip (e.g. white wall)

Try 1010tires.com and read the tire tech section, full of useful, understandable information with a tire size calculator to do the math for you. Oh, and unless it's a really unusual design, a 17" diametre wheel is either 7" or 7.5" wide.

Azzazzyn
03-31-2006, 05:19 AM
since you guys are so helpful, as you always are, wtf is an offset and what does it do?

roman
03-31-2006, 06:29 AM
http://www.tireguides.com/tips.html

Just read up on those links they should answer any questions you may have. The last one will answer your offset question.

david in germany
03-31-2006, 06:42 AM
since you guys are so helpful, as you always are, wtf is an offset and what does it do?
Welcome to the board, For your assistance we have a search button. Top Right or your screen...

Screw the conversions punch in your stock size and try what you are thinking of putting on here (http://www.miata.net/garage/tirecalc.html)

TEAMFaint
03-31-2006, 06:49 AM
Azzy, you want a good size for your car? I'm guessin your rims are 17x7..look at your stock tires and let us know what they currently are (I'd guess 215/55/15) Try to find something as close to stock as possible so your spedometer isnt outta whack. IMO go with 215/40/17..nice and wide for good grip, 40 series rubber is still a lot of rubber on the wheel, espically compared to 35 series.