tire sizing and wheels

[sei09]

hello evryone...especially the experts!!^^got a quick Qis 245/45/18 too big?i no 235/45/18 is just rite... but i am searching for a wheeltire comboi also saw 235/40/18...is this size alrite?

n wat do u guys think about these rims?THX alot!would love feedback!!




Modified by sei09 at 12:01 AM 1/30/2008

[Loop]

Diameter of the Tires:215/55/17...26.31225/45/18...25.97235/45/18...26.32245/45/18...26.68235/40/18...25.40

I recommend keeping the diameter number close to stock or your speedometer would either read to fast or slow. I would either go with 225/45/18 or 245/45/18 if your going with 18" wheels. 235 in general for tires is a awkward number and they are pricey.

You also need to take a consideration what the wheel offset and how wide the wheels are too if your going to drop the car later on. But with no information provided, I won't be able to tell you.

Example:My setup is 18x8.5 +45 offset with 225/45/18 with the tires inside the fender, while my wheel lip flushed. Which I should have no problem with dropping in the future.

[Shift_Altima]

Loop. With that setup.. are u over rotating or under rotating? Like 60 mph how fast are you really going and when you drive 1000 miles how many does it say you drove? thx

[johnny_d]

with a smaller diameter, he's under rotating very slightly. Prolly about 59.5mph when it says he's at 60.

http://www.miata.net/garage/tirecalc.html

use that to calculate

[milkacaduke]

So um wat is the best offset for A/C?

or different rim size have different perfect offset to fit the car?

i'm stupid i know

[johnny_d]

it will depend if you will drop the car or not. +45 seem to be a safe offset, provided your wheels aren't wider than 8.5 and your tires match OEM specs

[sei09]

HEY GUYS...thx for the tip!!another a quick Question

what does this mean?E.G..:Treadwear:340Treadwear:300Treadwear:280

AND ALSO.....for those of u who changed wheels...any mileage difference changing to a bigger sized wheel n tire?

[milkacaduke]

thanks for the reply johnny

for example if it's a set of 19 or 20

wat's the safe range of offsets and tiresize ?

[rjdmmfl1]

with a smaller diameter, he's under rotating very slightly. Prolly about 59.5mph when it says he's at 60.

http://www.miata.net/garage/tirecalc.html

use that to calculate

opposite, smaller diameter, you over-rotate, larger diameter, you under-rotate

[MidLife_Coupe]

Ok how about 19 inch wheels. For 2.5 A/C.I just bought a set of Infiniti G37 wheels and tires off ebay.

Front vs OEM 16

19x8.5 vs 16x7225/45/19 vs 215/60/16 ( overall dia diff is + .81)offset 43 vs 45 ( width diff is + .40)

Rear

19x9 vs 16x7245/40/19 vs 215/60/16 ( overall dia diff is +.56)offset 45 vs 45 (width diff is +1.19)

I have been going nuts trying to figure all this s*** out. I think I will be ofk. I am not planning on lowering this car. Too dam old for that stiff of a ride!!! Thanks for your help

Modified by MidLife_Coupe at 5:43 AM 2/2/2008

Modified by MidLife_Coupe at 5:45 AM 2/2/2008
Modified by MidLife_Coupe at 5:48 AM 2/2/2008

[chow]

Treadwear is wierd and there is no official way to compare them but heres how the unofficial system goes.

The base tire has a tread wear of 100. Just say your tire is rated 200, that means it will have 2x more life then a 100 tread wear tire. With a 300 rated tire it will have 3x the life. Just simple ratios.

[ursus]

Wow, these are the exact answers i need thanks! I'm plannin to put some 245/45/18s on 06 SE-R wheels, hopefully that'll be ok.

[rjdmmfl1]

Treadwear is wierd and there is no official way to compare them but heres how the unofficial system goes.

The base tire has a tread wear of 100. Just say your tire is rated 200, that means it will have 2x more life then a 100 tread wear tire. With a 300 rated tire it will have 3x the life. Just simple ratios.

true, but because there is no standard that anyone uses, the treadwear numbers from tire company to tire company is 100% useless. its only valid when comparing tires from the same company!