'05 X5 3.0i - replacing factory v-spoke wheels with 20" wheels
 

I have been reading posts for days trying to find out, what I think is a basic question. If the answer is indeed somewhere in here, I apologize in advance for this post.

I have an '05 X5 3.0i with the factory OEM 17" V-spoke wheels. I have found some wheels (replicas, I think - I have read the very informative posting on the buying guide for replicas) that I want to buy. Here is my question(s):

The 20" rims I want are 9.5" wide (I am not going to stagger, for tire rotation purposes). From research I have done so far, I was planning on putting 275/45/20 tires on. Will I have any clearance problems on the front or rear wells? I can't seem to find any specific answers to this question.

I am buying my tires from Discount Tire, and when I went in to research a tire, the manager said that a 20" wheel on the 3.0i X5 will affect the spedometer by 2 mph, @ 70 mph actual speed. Any truth here?

Also, do I need any camber adjustment on the rear?

Any comments is GREATLY apprciated!

Here is the wheel:
http://cgi.ebay.com/ebaymotors/ws/eB...ayphotohosting

:xoutpost: sorry might not be much help in terms of answering the Qs, but JUST DO IT!!! LOL. I would think it would fit no problem. the only thing is the 'non staggered' i guess. someone else more knowledgeable on the wheels can suggest.

You should'nt have any clearance problems with the wells. I put 20s (replicas/staggered) on my 3.0i (had factory 18s). I haven't had any clearance problems. As for the speedometer part..I'm not sure. Replicas usually weigh more than the OEM wheels...so they will have some kind of unnoticable effect..nothing major. But overall you won't run into major issues. Its definately a great investment. Just like the previous poster said, Just do it! haha.

The camber would remain the same with any wheel/tire. Alignments can change only if parts wear, or something gets bent or the alignment guy uses wrenches on it.

Note: demonic forces can alter the alignment when other people drive your car. The demons stuff freeway plants, dirt and wood posts under your X in an attempt to blame the innocent driver. I know this, scientifically, because the driver will very sincerely deny hitting anything. This has happened a couple of time with me, so I know...

It would be a good idea to have a competent alignment done whenever you buy new tires to preserve your investment.

Bad wear patterns tend to continue even after the alignment problem is corrected, so don't put it off or wait to see if a problem develops later.

On my 05 X, the alignment was quite good except for the toe-in. That caused a little drift to the left. Correcting that fixed the drift and made the X steer in that precise BMW way that sets it apart from other able competitors.

I just quit asking questions and bought the wheels from Eurotech Wheels in California. Had them mounted with Yokohama Prada Spec-X 275/45/20 and 295/45/20.

Looks great, wild-one!

The 168s look great! But according to your data, your fronts/rears have different rolling diameters. This WILL cause drivetrain issues - see this recent thread => http://www.xoutpost.com/x5-e53-forum/...hed-tires.html

Either go with the OEM staggered tires sizes or with all 4 same size. As you currently have, the rears are taller than the fronts, which is a no-no.

DKL,

Are you sure this will cause problems on this model? So I need to get... lets say 295/40/20's for the rear? How do I know how my current set up will effect the transfer case, or if it will at all on the 2005? The thread you sent, mentions pre-2004.... Please let me know what you know please...

It doesn't matter if your car is pre or post 2004, all AWD or 4WD vehicles require same rolling diameter on all 4 wheels. If the fronts and rears have different rolling diameters, guess which component have to take up the difference?

Unfortunately, if you want to go staggered, the OEM 275/40-20 and 315/35-20 combo is the only sizes that would provide you with equivalent rolling diameters. I did a quick calculations on all the sizes that you've mentioned:

275/40-20=28.66" approximate rolling diameter
315/35-20=28.68" approximate rolling diameter
275/45-20=29.74" approximate rolling diameter
295/45-20=30.45" approximate rolling diameter
295/40-20=29.29" approximate rolling diameter

As you can see, the OEM staggered sizes have nearly identical numbers.

Super-good info, dkl. I hope to get this fixed today. I am going to ask you a STUPID question, so bare with me: I assume all 2005 X5 3.0i are AWD, correct?

I actually did end up going staggered with the 20" wheels. They wanted $200 more to break the set.

If I stayed with 275/45/20 on the front and changed to 295/40/20 on the rear, will the .45" differential cause problems? The reason I ask is that my wife is the primary driver of the car. I had a '98 328i, that had "low profile" tires, and we spent more time at the wheel repair shop, than we did at home (kidding...) I want the most cushion to avoid as much as possible, bent rims...

As a side note, I bought my tires at Discount Tire, and I happen to know the manager at the location as well. I called him up yesterday and told him of this situation. He told me that DT does extensive research on vehicles, in relation to manufacturer models, wheel/tire size ratios, OEM reccomendations, etc. He said these sizes of tires that they put on for me were recommended, on the 3.0 with 20" wheels... after my story, he sounded really concerned (I was in a near panic) and he said he will calling into their "technical services division" ASAP this morning. He went as far to tell me that they have put these same tires on the same X5 3.0 models previously, and to date has not heard of any problems.

DKL, you have provided excellent information. I will post what we figure out today, in case it may help someone else.

Yes...ALL X5s are AWD.

Unfortunately, no one knows what the long term ill effect would be running the 0.45" differential. I supposed it's equivalent to running an almost bald set of fronts with a brand new rears with full thread thickness.

Frankly, I'm not sure where your tire guy got those tire sizes from. The OEM sizes would work on all X5s, whether 3.0i, 4.4i, 4.6iS, or 4.8iS.

FYI...the differences in side profiles between the 295/40-20 and 315/35-20 is negligible as my above calculation showed. Why? 40% of 295mm is your side profile (295/40-20) versus 35% of 315mm side profile (315/35-20).

Here is the fix (DKL, I think you will agree - I hope so anyway and I am very eager for your reply) :

We replaced the front tires this morning, with 265/50/20 and kept the rears with 295/45/20. All the tires fit the rims well, and all tires have wheel well clearance.

The overall diameter on both sizes are now identical at 30.6" and the revs per mile are also identical at 679. I could not figure out your formula for determining the rolling diameter, but do know according to the revs per mile and the overall diameter they will mathematically get the same rolling diameter, for each size.

Here is the specs for the Yokohama Parada Spec-X:
http://www.yokohamatire.com/tires/sp...ARADA%20SPEC-X

I hope my "crisis" is avoided and I can get on enjoying the X5 ride...:D

It looks like that combo will work. My theoretical calculations are:
265/50/20=30.43"
295/45/20=30.45"
Tires from different manufacturers will vary slightly even for the same specified size (due to different thread depth, etc...). That's why you don't want mixed tires from front to back or side to side on AWD.

Your new tires are still a bit taller than the factory 17s (235/65/17=29.03"), so it will throw off your speedo a bit (you'll be going slightly faster than what's indicated). But that's no biggy since the factory speedo is a bit optimistic to begin with anyway.

I just got lazy and copied this from the training book for you, this is for post facelift X5's with xDrive only, itis hard parts failure on pre-xDrive X5's.. enjoy!

http://i140.photobucket.com/albums/r.../xdrive015.jpg

W, Thanks for the excellent info! I learned something new about the X everyday. Even though it's designed into XDrive to allow for slight tire circumference deviation, prolonged transfer case clutch slippage cannot be a good thing on the TCase when the differential increases, right?

Correct. Just think of it in terms of clutch wear, but the clutch packs are loaded by electric actuation and connect your front wheels.

I had excellent results using 295/40-20s F&R on staggered 20" wheels. I had no circumference issues. See the FAQ page for more info on my experience and that of others who have done this mod.

Wild-one, you're fortunate to have such a friend who would swap you out after mounting and installation of the first set of tires! I'm glad it worked out.

If you used the same size tires front and rear, then why in the hell did you buy staggered wheels?!? That kinda defeated the purpose of having the wider wheels in the back!

Yeah, I did get lucky. He said it was no big deal and did not charge me anything at all, to do the swap... thanks for the replies everyone - this was definately a good learning experience.

I am feeling a very slight "shimmy" now while driving at highway speeds. Is this suspension parts wearing because of the larger wheels/tires?

Kinda hard to say, it could be a lot of things.

First things to check could be:

- Wheel/Tire balancing
- Wheel Alignment

If you have a trusted mechanic, have him check it out. I say trusted because, if not, all of a sudden you might have other things needing repair too! :D

Good luck! :thumbup:

Absolutely. Send them to me before your X is ruined. I'll send you my stock sized wheels and tires in return.

Just trying to help.

If that works, I have a bridge to sell ya! :rofl:

good try carlgo and weasel...and dang funny too! the right front was out of balance by an ounce...

Thats about 30 grams. So yeah, that would cause a lil shimmy. So now you're back to riding smooth :D

Hi I am sorry to message out the blue but I have the x5 and want this setup and just wanted to see if you remember if you had any issues with the transfer case or gearbox thanks