225/35/19 & 265/30/19

[nate96]

I currently have General Exclaim UHP 235/35/19 and 265/30/19 on my 06 Si Coupe. I have a small rubbing issue. So I would like to go to a slightly smaller tire (225/35/19) up front. As I live in Canada I want an All-Season tire as we still have snow on the ground and it is getting below freezing at night. The Continental ExtremeContact DWS seem to have good reviews but is only available in a 265/30.

Does anyone have this setup or experience with these tires?


http://www.tirerack.com/tires/survey...jsp?type=UHPAS

Thanks.

[mjnt]

I'm running the same setup as you and having the same issue. The front is rubbing slightly and I was thinking to put 225/35/19 just like you thought but my mechanic told me it doesn't matter if I go down from 235 to 225 it will still rub.

[v3.0si]

it depends greatly on offset whether or not it will continue to rub on 225/35. what is the front wheel spec? if mjnt is using an 8.5" et35 and you're using an 8.5" et40... chances are the 225/35's on his will still rub, but yours won't. also, the pitch of the sidewall can differ greatly between manufacturers. most bridgestones, for example, have a very rounded shoulder compared to most dunlops. easiest way to check is to turn your wheel to the point where it begins to rub. compare the difference in section width and rolling diameter between the tire you're on now to the tire you would like to use. some quick measurements with a METRIC ruler or caliper will show how much room you'll gain by switching to the 225/35's. the width of the "burn" mark on your 90deg splash shield is a great way to measure the amount of deflection your current tire is going through.

if you've done all that and it's still too close to call, head to your local home improvement store and get a pivoting angle finder 18"-24" long. (i got mine from lowe's for ~$12. it's clear with blue markings.) turn your wheel to where it makes contact with the shield, and place the angle finder on the floor with one leg parallel to the length of the car (quick tip, use the expansion cuts in your garage floor or driveway and align the car to one of those. it'll simplify things greatly since the closer it is to 90deg, the easier it will be to find the missing angle), and the other leg parallel to the face of the wheel (this is really the one that matters). that angle directly corresponds to the small cross-sectional "triangle" the tire is at just before contact with the shield. the width of the "burn" will give you one of the three legs in the imaginary "triangle" the the tire would be in if the shield weren't there. again, cross reference to the 225/35 specs should give a very close approximation of how that tire will behave in comparison to the 235/35. and remember triangles are easy... angle A + angle B + angle C = 180deg. with all three angles known and one of the legs also known, the other two legs can be sciphered with a bit of trig.

the 3rd way is to head to a local tire shop that is willing to let you test fit with somebody's spent tread, or "take-off". this will cost 2 tires worth of mount and balance, but is very practical if you're not into the whole math thing.

conti extremecontact dws' are phenominal tires. i've switched e90's over to them from the procontact ssr's and have gotten an extra 10k mi out of them, plus the chopping/feathering issue is much diminished. they are a bit louder than the procontacts, but that doesn't matter much since you're probably not on those now.

[THE JEDI]

okay I got a question for you guys HELP a brother out..will my stock rims hold 255/45/17 in the rear......

[v3.0si]

Originally Posted by THE JEDI

okay I got a question for you guys HELP a brother out..will my stock rims hold 255/45/17 in the rear......

which wheel are you wanting to put these on?

[THE JEDI]

Originally Posted by v3.0si

which wheel are you wanting to put these on?

http://www.finishlinewheels.com/BMW/Z4/2004/


sixth wheel down #103

[v3.0si]

Originally Posted by THE JEDI

http://www.finishlinewheels.com/BMW/Z4/2004/


sixth wheel down #103

i'm not sure 255's are a good idea on that narrow of a wheel.

the biggest tire i'd put on there is a 245/40r17. this would keep the rolling radius close to OE, and they'll safely fit the rim.

[THE JEDI]

Originally Posted by v3.0si

i'm not sure 255's are a good idea on that narrow of a wheel.

the biggest tire i'd put on there is a 245/40r17. this would keep the rolling radius close to OE, and they'll safely fit the rim.

Aight I will take your word on that one...so now I got two perfectly good tires to get rid off..LOL