Correct Tire Size

[clint]

I can't seem to find the information on the internet.Different tire shops give me different answers.What is the recommended or correct tire width for the following rims ?18" x 8J = 225/40R18 ?18" x 8.5J = 255/35R18 ?18" x 9J = 255/35R18 ?

 

[guru]

IMHO- everyone you ask will have different opinion, I think got 'general guide' but it really depends on the look you want, level of grip, your ride height and couple of other things you need to consider before deciding.

 

[GHS]

Bro looks about right.
Front 18 x 8 you can go for 225/40 R18 tyres.
Rear 18 x 8.5 or 18 x 9 you can go for 255/35 R18 tyres.

This is the standard setup for BMW, refer to the E90 wheel/tyre specs:
http://zoouz.free.fr/e90_wh.htm

 

[wan520i]

clint,

After my quick research on your good question, here I found:

225/40/18 tires are approved on rims width from 7.5j to 9j.
255/35/18 tire are approved on rims width from 8.5j to 10j.

For more information, please refer to falken's web. Go to tire specification.

Hope this help!

 

[Mouse]

I can't seem to find the information on the internet.

Different tire shops give me different answers.

What is the recommended or correct tire width for the following rims ?

18" x 8J = 225/40R18 ?

18" x 8.5J = 255/35R18 ?

18" x 9J = 255/35R18 ?

http://www.miata.net/garage/tirecalc.html
compared your stock & intended upgrade size and make sure it doesn't exceed 3% in speedo error, the closer to 0% the better

 

[Impulse]

Clint,
I am using the Conti 225/15/16 rims as original on my 325i.
Many of the members here may use larger rims like 17,18 and even 19 but I can assured you those rims will induce penalties like higher fuel consumption, excess
strain on the suspension,power loss and quicker wear and tear which are not healthy for the wallet.
Bigger rims are heavier and low profile tyres are expensive.Our Malaysian roads are
full of bumps and potholes and if you not careful, you will dent or even crack your rims.Go to Bandar Sunway rims accessories shops and you can find piles of damaged
rims.
You will definetly lose power as more torque is required to turn the bigger and heavier rims.If you are the racing type,you will notice your car will not reach it maximum speed.Some one here already send a post about this.
Bigger tyres and rims are more for comestic look and good to be driven around town
for others to see.
Unless you had a more powerful E46 330i, then go for it, by all mean.
Hope this info will help.
:burnout: :burnout: :burnout: :burnout: :burnout: :burnout: :burnout: :burnout:
Regards,
Impulse:burnout:

 

[clint]

Impulse, thanks for your advise.

My car comes standard with 8Jx18 (225/40R18) front and 8.5Jx18 (255/35R18) rear. I am changing my rims only (not tires). Can't seem to find any rims 8Jx18 front with 8.5Jx18 rear. There are lots of 8Jx18 all around, 8.5Jx18 all around or 8Jx18 front with 9Jx18 rear.

Just to satisfy my curiosity, I tried fitting my Michelin PilotSport2 225/40R18 onto a 8.5J rims and 255/35R18 onto a 9J rims. Looks damn ugly - rim too big for the tire.