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[F06msportmia]

What's up forum!

I know that there might be posts out there for this question but I have looked and unfortunately I haven't found any. So hear it is!

Is it recommended or correct to run the following setup?
2006 325i sport package (stock).

235/40/18 (front)
265/40/18 (Rear)

Any help is greatly appreciated...

[LivnLife31]

That's what I am running on stock 189's.

[anerbe]

it's recommended to keep as close to the factory stagger ratio. you want to avoid having major differences in rolling diameter, as the DSC system detects wheel speed differences to activate.

although the threshold for % difference has been debated (1%, 3%, etc...), basic system knowledge suggests lower numbers are better.

225/40 and 255/35 18" is roughly a 0.4% difference in rolling diameter
235/40 and 265/40 18" is roughly a 3.4% difference in rolling diameter

I would have suggested a 235/40 and 265/35 18" which is roughly a 0.4% difference.

You might not experience problems, but search the forum - there are some cases where DSC either had an error or was going off during normal driving, and some people suggested the wrong stagger sizes to blame.

[zipstic]

You also need to take into account the brand and model of the tire since they have different rolling diameters by size. For example I'm running 225/35/19 front and 265/30/19 rear Hankook V12's, but if I would have gone with Conti DW's I would've ran a 235/35/19 and 265/30/19.

[F06msportmia]

Thanks everyone for the input. I will be going with:

235/40/18 (front)
255/40/18 (rear)

I dont want to go any lower then 40 cause then it just looks off for being stock wheels, now if we were talking about 19" the 35 is the way to go. Thanks again!

[anerbe]

Originally Posted by zipstic

You also need to take into account the brand and model of the tire since they have different rolling diameters by size. For example I'm running 225/35/19 front and 265/30/19 rear Hankook V12's, but if I would have gone with Conti DW's I would've ran a 235/35/19 and 265/30/19.

True -

Best way is to check rolling diameter specs on Tirerack for the specific tires in question.

[anerbe]

Originally Posted by miamimbj

Thanks everyone for the input. I will be going with:

235/40/18 (front)
255/40/18 (rear)

I dont want to go any lower then 40 cause then it just looks off for being stock wheels, now if we were talking about 19" the 35 is the way to go. Thanks again!

Just curious - the factory/stock 18" rear size is a 255/35R18.

If you think the stock 3 series sport wheel looks odd, go for the 40. Otherwise, it looks just fine to have the 255/35

255/40 would look pretty chunky - I have 245/40 in the front at one point, and it looked a bit too meaty for me. I can't imagine a 255/40. I'm now down to a 235/40 front and 255/35 18"

[F06msportmia]

Anerbe:

Thanks for the recommendation perhaps I am going to look into what you suggested. I will post pics once I get them on the ride...

[AWDBooSTIn90]

I know this is an old post, but I can't seem to find a good answer anywhere, by searching on the forum.

I have oem BMW 189 wheels
F: 18x8"
R: 18x8.5"

Stock tire sizes (currently installed sizes aswell)
F: 225/40 - 18 *(8" Wide Rim)*
R: 255/35 - 18 *(8.5" Wide Rim)*

Now I haven't really had any problems with the stock tire sizes, but now its time for new tires.

I live in NY (LI to be exact) and the roads here are not good. Especially if i have to travel anywhere, that means im going thru NYC to get there. Even worse for potholes... But this is not my DD and won't be driven in the snow unless absolutely unavoidable.

So ive been looking at a few different tires
1) Conti ExtremeContact DWS
2) Hankook Ventus V12

Another thing is my 335i coupe is modded and will be continued to be modded til about the FBO level. So grip is also becoming an issue.

Now what tire sizes have people ran on the stock oem sport package coupe BMW 189 (18") staggered wheels to gain a little more width without over doing the tire size based on rim width (seems like limiting factor) and possibly step up to a 40-series sidewall for the rear for more sidewall and tire protection from pot holes pinching the sidewall and getting blow outs or just plain huge potholes destroying a low profile stock sized tire...

I want to keep rolling diameters close like stated above. I think it's important not to overlook that since the DSC uses tire speed differences to do its job, bc that will affect wheel speeds front vs rear bc of a different rolling diameter, for example.

So what sizes can i safely run without having an ugly huge bulging sidewall that kills handling...

Possible to run 245/40 on an 8" wide wheel?

How about 265 or even 275 width on the rear wheels which are 8.5" wide.

Im currently looking to order 4 new tires by the end of the week.

And i think i wil order off tire rack . Com .... Anyone have any input or suggestions on that site or other places to consider ordering from?

Right now, since summers almost over anyway im looking at the best performing Ultra High Performance All-Seasons, and come spring time i will be ordering some proper new wheels with some width to them and max performance summer tires to go along with the new wheels and have that be my spring & summer wheel/tire setup... But thats a whole other topic lol..

Anthony

[Antetokounmpo]

245/40 on a 189 18x8 Untitled by Bryan Kendall, on Flickr

DSC_0029 by Bryan Kendall, on Flickr

You can run a 265 on the rear. Probably have to go 265/35 though. 275 is too wide for a 8.5'' width and 265/40 is too tall.

[AWDBooSTIn90]

I appreciate the quick response and the pics are very helpful.

Im pretty convinced on the front tire size. Looks like it fills the wheel gap better, slightly wider tire, and more security with the extra sidewall for potholes...

Now for the rear, i want to check the rolling dia for the 245/40/18 vs 265/35/18.

Hmmm.... Decisions, decisions.... Lol

[Antetokounmpo]

Originally Posted by AWDBooSTIn90

I appreciate the quick response and the pics are very helpful.

Im pretty convinced on the front tire size. Looks like it fills the wheel gap better, slightly wider tire, and more security with the extra sidewall for potholes...

Now for the rear, i want to check the rolling dia for the 245/40/18 vs 265/35/18.

Hmmm.... Decisions, decisions.... Lol

The 265/35 will be like .35 inches smaller.

[AWDBooSTIn90]

Originally Posted by Harambe

The 265/35 will be like .35 inches smaller.

Is that ok?

Whats the difference in inches on the stock sizes 225/40/18 vs 255/35/18 in rolling diameter? Do you know by any chance? Otherwise ill figure put how to check when i get home..

[Antetokounmpo]

Originally Posted by AWDBooSTIn90

Is that ok?

Whats the difference in inches on the stock sizes 225/40/18 vs 255/35/18 in rolling diameter? Do you know by any chance? Otherwise ill figure put how to check when i get home..

They're the exact same size. With rwd it really doesn't matter since they difference is pretty small. It'd be mostly about looks at that point.

[AWDBooSTIn90]

Originally Posted by AWDBooSTIn90

Is that ok?

Whats the difference in inches on the stock sizes 225/40/18 vs 255/35/18 in rolling diameter? Do you know by any chance? Otherwise ill figure put how to check when i get home..

So i got my new tires:
Continental Extreme Contact DWS 06. Went with the sizes below. Same in the front but slightly wider on the rear tires for more traction.

F: 225/40R18
R: 265/35R18 (About .5"-1" wider tire than stock and 1/4" taller sidewall)
(These are .02% different in rolling diameter)

Ths Rear tires look basically the same as before, but just seems more aggressive and noticeably wider at the same time lol. Just an overall more sporty look.




OEM Stock sport package tire sizes are below:
F: 225/40R18
R:255/35R18
Comes out to a .03% difference in rolling diameter, F vs R.


Also another matching tire size setup i found if you want to upgrade the front tires also is below. Theyre close enough to retain stock-like rolling diameter differences, which it is with something like, 0.8%.
So that means its also compatible with Xdrive's as well.

F:245/40R18
R:265/40R18


(Just for reference and comparison, 3% of rolling diameter difference, F vs R, is required).

There are some 275/295 sizes to play with if you go with wider wheels. You just need to find a good sized front tire for the rear tire size you want to run and get the desired side wall height your after. So basically just need the front to rear close enough in diameter.

I really like the Conti DWS 06. Super smooth. Very grippy and quick to turn in.
I wanted a good set of UHP all seasons. And i happen to find a good deal before i decided on these after looking at specs and reviews. The reviews on tire rack are mainly good, so i went for it.

I am going to eventually buy some new wheels, ill put Michelin PSS's on and run at least a 9" wide wheel, these will be my future summer set. These for now will be fine lol

[Antetokounmpo]

Originally Posted by AWDBooSTIn90

So i got my new tires. Continental Extreme Contact DWS 06
F: 225/40R18 (stock size)
R: 265/35R18 (About .5"-1" wider tire than stock and 1/4" taller sidewall)
Rear tires look basically the same but alot more aggressive and noticeably wider, more sporty look.
These are .02% different in rolling diameter


Stock sport package size and what i was running:
F: 225/40R18
R:255/35R18
Difference in rolling diameter for stock is .03%. Very close.

Now another tire size setup i found with a below 1% rolling diameter difference, (below 3% is recommended). However the 8" wide front wheel is not wide enough on the 189's to do.

F:245/40R18
R:265/40R18

There are some 275/295 sizes to play with and balance the front to rear will keeping them close enough in diameter.

I really like the Conti DWS 06. Super smooth. Very grippy and quick to turn.
Now i wanted a good set of UHP all seasons. And i got a good deal and liked the reviews on tire rack so i went for it.

I am going to eventually buy some new wheels, ill put Michelin PSS's on and run at least a 9" wide wheel, these will be my future summer set.

FYI a 8" 189 wheel can certainly run a 245, I've done it before.

Also... by that logic, a 265 definitely wouldn't work on a 8.5" 189 since there's almost a 1" difference between 245 and 265 and the wheel is only .5" wider.

[AWDBooSTIn90]

Originally Posted by Harambe

FYI a 8" 189 wheel can certainly run a 245, I've done it before.

Also... by that logic, a 265 definitely wouldn't work on a 8.5" 189 since there's almost a 1" difference between 245 and 265 and the wheel is only .5" wider.

Didn't know that, good to know for next time. Hows it look?

I like the look of the 265 rear tire. Doesn't look like its too wide for the wheel at all and deff looks more aggressive now versus before. (old tires were a different brand though)

Im also really impressed with these tires. So much grip for an all season and rides very comfortable, but firm at the same time. I went to six flags over the weekend and its about a 2hr drive each way for me. Feels like a bmw should feel cruising down the highway. High speed 100~+ driving feel is tight and smooth, stays dead straight.

[Antetokounmpo]

Originally Posted by AWDBooSTIn90

Didn't know that, good to know for next time. Hows it look?

I like the look of the 265 rear tire. Doesn't look like its too wide for the wheel at all and deff looks more aggressive now versus before. (old tires were a different brand though)

Im also really impressed with these tires. So much grip for an all season and rides very comfortable, but firm at the same time. I went to six flags over the weekend and its about a 2hr drive each way for me. Feels like a bmw should feel cruising down the highway. High speed 100~+ driving feel is tight and smooth, stays dead straight.

Scroll up about 6 posts.. I already posted pictures.

[AWDBooSTIn90]

Originally Posted by Harambe

245/40 on a 189 18x8 Untitled by Bryan Kendall, on Flickr

DSC_0029 by Bryan Kendall, on Flickr

You can run a 265 on the rear. Probably have to go 265/35 though. 275 is too wide for a 8.5'' width and 265/40 is too tall.

+1 on your pics posted earlier. Didn't see the post at all..

And yea the 265/40-18s do look just alittleee too tall.
However, you can use them and there was no rub my E92 when i had them on, for about 2 miles...
I would say only go with this size if your looking for something with a slightly taller sidewall and just a bigger looking tire, in general.

But 265/35R18 is just the right fit to me, while still upgrading to wider rubber slightly on an oem wheel.

I must of missed that post. .. Wpuld of answered a lot of questions I couldn't find answers too while searching..

They look good on the 189s. Next time I'm def going to go with the 245 front tire. And stick with the 265 rear. I like the look and the grip. The rear tires are soo much more expensive than say a standard 225/40R18 sized tire. But these cars need the extra width in the rear on RWD cars especially and they need the extra grip in the front to reduce understeer a little, with the right mods.