Wheels and staggered setup?

[321demot]

Looking to get 17 x 8.5 235/40/17 on front and 17 x 9.0 245/40/17 on the rear.



LTW5 Lightweight Alloy Race Wheel from Tuner Motor sport btw if anyone has them please tell me how you like them.


Is it a bad idea to have wider tires on the back and If I do should use 235/40 or 245/40 on the front and 245/40 or 255/40 on the back. sorry about the nub questions its just I am spending a lot of money on this and want to get the best I can for the money.

[Jeron]

Staggered doesn't hurt but the handling wont be neutral. You wont notice it in street driving. The diff between 235/40 and 245/40 is small.

There is no reason not to got 245 in front. With stock offset on 8.5" 245 will not rub. If you are going to get 245 all around just get the same width rim all around. Depending on offset spacers may be needed.

[mryakan]

Staggered doesn't hurt but the handling wont be neutral. You wont notice it in street driving. The diff between 235/40 and 245/40 is small.

There is no reason not to got 245 in front. With stock offset on 8.5" 245 will not rub. If you are going to get 245 all around just get the same width rim all around. Depending on offset spacers may be needed.
That is good to hear, I plan to go 245/40/18 all around on 18x8.5 rims on my '07 e90, so I assume I won't have any problems either? I was worried mostly about handling with the wider tires in the front since BMW recommends 225 up front but those won't work great with the 8.5 wide rims.

[Jeron]

Hold on a sec. My post was RE his 17" rims.

If you are using 18" then 245/40 will be 1" bigger and could interfere. If 245/40R17 is the size you have now then you need 245/35R18 to maintain diameter.

I dont know E90 tire fitments, although it is similar to E36 and E46, but you need to be careful picking your offset..

[mryakan]

Hold on a sec. My post was RE his 17" rims.

If you are using 18" then 245/40 will be 1" bigger and could interfere. If 245/40R17 is the size you have now then you need 245/35R18 to maintain diameter.

I dont know E90 tire fitments, although it is similar to E36 and E46, but you need to be careful picking your offset..
I am not too worried about offset (and I hope I am not wrong on this), since the sizes come recommended by the vendor and they fit them specifically to e90s. I am just wondering about the handling aspects of 245s up front. I did some calculations and the 245/40/18 are within 3.5% off the stock. I have a much more selection choice with the 245/40. I am thinking 3.5% is not too much of a diff or is it?

[Jeron]

Like I said I don't know E90 tire fitments. What are your current tire sizes?

Removing/reducing the stagger reduces understeer. It's not something you'll notice unless you are getting into your traction control. You will notice the weight extra effort turning the bigger rims and wider tires. You will also notice the shorter sidewall.

This will save you time on the calcs:
http://www.discounttiredirect.com/direct/brochure/info/tmpInfoTireMath.jsp

[mryakan]

Like I said I don't know E90 tire fitments. What are your current tire sizes?

Removing/reducing the stagger reduces understeer. It's not something you'll notice unless you are getting into your traction control. You will notice the weight extra effort turning the bigger rims and wider tires. You will also notice the shorter sidewall.

This will save you time on the calcs:
http://www.discounttiredirect.com/direct/brochure/info/tmpInfoTireMath.jsp

stocks are 225/50/16 not sure what the rim dimensions are.
Great link btw, many thanks. Glad my calculation turned out to be 100% accurate :-).

[Jeron]

That size is not approaching the max the car can take so its tough to go from there.

The 335 Sport takes 225/40R18 and 255/35R18. Which is pretty similar to the E46 dimensions. I suggest that if you go with 245 18 you get 35 not 40 series.

Also going from 225 50R16 to an 18 is a big jump and will significantly change how the car feels and handles. If you at all like the comfort of the car as it is now the I suggest 245/40R17 as an incremental step up. I prefer that size over 245/35R18 on both my modded E36M3 and my E46/330i. It doesn't have the looks of the 18 but it handles better and is more compliant.

[mryakan]

That size is not approaching the max the car can take so its tough to go from there.

The 335 Sport takes 225/40R18 and 255/35R18. Which is pretty similar to the E46 dimensions. I suggest that if you go with 245 18 you get 35 not 40 series.

Also going from 225 50R16 to an 18 is a big jump and will significantly change how the car feels and handles. If you at all like the comfort of the car as it is now the I suggest 245/40R17 as an incremental step up. I prefer that size over 245/35R18 on both my modded E36M3 and my E46/330i. It doesn't have the looks of the 18 but it handles better and is more compliant.
Thanks Jeron, you've been great help. I plan to stick with the runflats, so if I go 245/35 my choice is limited to the Potenza and I am screwed if they discontinue that size of just jack up the price. With 245/40 I have more variety and in fact I found the ContiSportCotact 3 SSR is 60$ cheaper per tire than the Potenza :eek:! I want the CSL replica wheels which only come in 18 and 19, otherwise I'd have chosen 17. With all this being said, I am willing to accept a bit of harshness in the ride, I come from an e36 anyway and that car was great but not tops in comfort. My worry is mainly fitment. I am going on vendor trust (modbargains), they say the 245s with their 18x8.5 and et40 should fit upfront no problem, but that is my only concern. The rear is not really much a concern, there is plenty of room. As for the difference of the 245/40, it comes out to it reporting 3.5km per hour less than stock at 100kph (i.e. says 100 when I am going 103.5), not a big penalty IMO, esp. that BMW over reports the speed anyway, and I guess the odo will read a grand less by the time I turn in the leased car, not a bad bonus ;).

Am I mislead? Again this is my 1st, so although I am researching a lot, nothing beats experience, so I do appreciate all the feedback.

[Jeron]

If your vendor says the 245/40R18 then great.

I had a staggered set of Michelin PS2 ZP 225/40R18 and 255/35R18 on 8" and 8.5" Z4 rims on my 330i for a year or so. Free from Michelin Research who runs tests near me. Gotta love free.

Anyway I didnt hate them but I could feel their weight in every acceleration and maneuver. You are already on run flats so the change might not be as drastic.

[mryakan]

If your vendor says the 245/40R18 then great.

I had a staggered set of Michelin PS2 ZP 225/40R18 and 255/35R18 on 8" and 8.5" Z4 rims on my 330i for a year or so. Free from Michelin Research who runs tests near me. Gotta love free.

Anyway I didnt hate them but I could feel their weight in every acceleration and maneuver. You are already on run flats so the change might not be as drastic.
Yeah free rocks, quite a deal you got. Do you race? Connection through that avenue I presume?

[mryakan]

If your vendor says the 245/40R18 then great.

Well modbargains says 245 will be ok, I am asking them again. EAS says they will probably rub and recommend 235/40, but there are NO RFTs in that size :(. I have the strangest feeling this may be a costly learning experience.

[Jeron]

Nope, they asked the local BMWCCA because they like to test on E46's and thats a good way to get a bunch of 'em.

I have a set of Dirreza Z1's I got for free, before they hit the market, when Oktoberfest was here last year. Dunlop was looking to have their new tires on the track at the event. I'd say it has worked out for them because they are fantastic tires and I promote them often.

[Jeron]

You should call the Forum Sponsor, Tire Rack. I cant recall the name of their specialist but he patrols this board. Jim maybe.

[mryakan]

You should call the Forum Sponsor, Tire Rack. I cant recall the name of their specialist but he patrols this board. Jim maybe.
Good call. I tried to contact him a few days ago but he was away, bet he is back now. I'll give him a call if he doesn't respond here. I have a post in the sticky thread that he replies to often.

[mryakan]

Can you have different size tires with same wheels all around. Like if I go 18x8.5 all around, can I do 225/40/18 front and something wider in the rear? What would be a reasonable size?

[Jeron]

I've done 245/40 and 255/40 stagger on the same rims. 225 is kinda narrow for 8.5" 235 would fit nicer

[spitfire1999]

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