wheels/tires to maintain stock gearing?
#1
wheels/tires to maintain stock gearing?
Im looking into putting 17's or 18's on my 03 wrx wagon, and wanted to know what size tires won't screw up my gearing, odometer, etc. Currently the car is bone stock. Thanks
#2
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What width are you wanting to go with? The stock tires have an od of 631.9mm, a 225/45/17 od is 634.3 (+2.4mm), a 225/40/18 is 637.2 (+5.3mm) and a 215/40/18 is 629.2 (-2.7mm). On a 225/45/17 tire the 225 is the width in mm, the 45 (profile) means 45% of the width which in this case is 45% of 225mm and the 17 is the wheel od in inches.
This is the way to figure out the od of a tire. (I will use a 225/45/17 as an example)
(1) multiply the width and the profile (225x.45=101.25mm)
(2) multiply x 2 (101.25x2=202.5mm)
(3) add the od of the rim (1"=25.4mm so 17x25.4=431.8) (202.5+431.8=634.3)
If the way I explained this is to confusing tell me what width tire you are going with and I will figure it out for you.
This is the way to figure out the od of a tire. (I will use a 225/45/17 as an example)
(1) multiply the width and the profile (225x.45=101.25mm)
(2) multiply x 2 (101.25x2=202.5mm)
(3) add the od of the rim (1"=25.4mm so 17x25.4=431.8) (202.5+431.8=634.3)
If the way I explained this is to confusing tell me what width tire you are going with and I will figure it out for you.
Last edited by MO REX; 08-07-2004 at 09:44 PM.
#4
the easy way:
http://www.miata.net/garage/tirecalc.html
http://www.miata.net/garage/tirecalc.html
#5
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Originally Posted by jdepould
the easy way:
http://www.miata.net/garage/tirecalc.html
http://www.miata.net/garage/tirecalc.html
Thanks for the cool link.
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The closest match to 205/55R16 is 215/45R17. That's the size tires used on the factory option 17" wheels (not STi). But 225/45R17 is really close too, so use that if you want.
#8
Thanks a lot, great response MO REX. That gives me a good idea of what to look for. Would the 215/45r/17 fit better on 7in or 7.5in wide rims? Also does anyone know about rubbing issues for a 225 45 17 with a stock suspension set up"
Last edited by rex17; 08-16-2004 at 10:02 AM.
#10
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Originally Posted by rex17
Thanks a lot, great response MO REX. That gives me a good idea of what to look for. Would the 215/45r/17 fit better on 7in or 7.5in wide rims? Also does anyone know about rubbing issues for a 225 45 17 with a stock suspension set up"
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Originally Posted by rex17
Im looking into putting 17's or 18's on my 03 wrx wagon, and wanted to know what size tires won't screw up my gearing, odometer, etc. Currently the car is bone stock. Thanks
#13
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Originally Posted by rex17
Thanks a lot, great response MO REX. That gives me a good idea of what to look for. Would the 215/45r/17 fit better on 7in or 7.5in wide rims? Also does anyone know about rubbing issues for a 225 45 17 with a stock suspension set up"
Like Ban said both will work with the stock suspension but if you plan on lowering the car in the future you may rub with a 225 depending on the tire and offset of the wheel. Different tires have different physical widths so one manufacturers 215 may actually be the same physical width as another manufacturers 225.
My 02 sedan has 225/45/17 SO3's on wheels with a +48 mm offset, it is lowerd 1.2" (rear) with 1 degree of - camber and the tires rub the fenders when I push the car hard on sharp corners. If you had a similar setup in the future you would definately rub since wagons have less room in the rear fenders than sedans.
Hay Ban (or anyone who knows), if he does plan on lowering the car in the future do you think he would be better off with a 48 or 50 mm offset since he has a wagon? I would guess a +50 but I dont know much about wagons.
Last edited by MO REX; 08-17-2004 at 05:11 PM.
#14
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WRX usable tire sizes and diameters
15"
195/65-15 25.0
205/60-15 24.7
16"
205/55-16 24.9
225/50-16 24.9
17"
215/45-17 24.6
235/40-17 24.4
225/45-17 25.0
18"
215/40-18 24.7
225/40-18 25.1
15"
195/65-15 25.0
205/60-15 24.7
16"
205/55-16 24.9
225/50-16 24.9
17"
215/45-17 24.6
235/40-17 24.4
225/45-17 25.0
18"
215/40-18 24.7
225/40-18 25.1
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