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[JaysBlueE92]

So I am about to mount a new staggered setup on my pre lci e92 xi and am somewhat worried because the tire sizes I need to run are different than what's been on the car for a majority of it's life.

I am coming from a staggered 19x8.5/19x10 setup with the common 235/35 265/30 tire setup. However my new wheels have a little more aggressive offsets and I think I need to run a stretched tire to clear fenders.

So my question is should i be concerned that my transfer case may act up after putting on the new setup? I've heard it could confuse the system and cause issues. The new tires will be 225/35 and 255/30.

[WilliamS]

Keep the tire diameter as close as possible. I forget the amount you can variate front to back but keep it as small as possible. You can run any widths you want, just keep the overall tire diameter the same. Tire rack makes it easy with Rotations per mile listed for tire sizes on the site.

Originally Posted by Goofyguy

Tire rack makes it easy with Rotations per mile listed for tire sizes on the site.

This forum makes it easier with a calculator at the top of the page...

[JaysBlueE92]

Originally Posted by Goofyguy

Keep the tire diameter as close as possible. I forget the amount you can variate front to back but keep it as small as possible. You can run any widths you want, just keep the overall tire diameter the same. Tire rack makes it easy with Rotations per mile listed for tire sizes on the site.

Originally Posted by FCobra94

This forum makes it easier with a calculator at the top of the page...

Not really what I was asking guys, but thanks. I am more interested in whether or not my transfer case will be affected/confused by the new tire sizes compared to old. Both sizes are within the allowed percentage according to calculation so that is not the issue

[WilliamS]

Your speedo might be affected but the transfer case and diffs wont care about the size of the tires as long as they are the same.

[VMRWheels]

You should be fine. I would recommend familiarizing yourself with 1010Tires tire size calculator, where you can input the year/make/model/trim and plug in what you're looking for.

http://www.1010tires.com/Tools/Tire-Size-Calculator

[flip4335]

Here is another link to check the min/max wheel width a certain tire size will fit:

http://www.rimsntires.com/specs.jsp

IMO, the fronts/backs that come closest in 19-inch wheel diameter are:

225/35/19 Front; 265/30/19 Rear, or
235/35/19 Front; 275/30/19 Rear

Cheers!

[JaysBlueE92]

guys, this isn't about the rolling diameter as I stated. I know how to use the calculation tool for keeping the percentage in check.

I am more so concerned with my transfer case acting up because my car has adapted to the current tire setup, 235/35 and 265/30. This user had an issue I am talking about http://www.e90post.com/forums/showthread.php?t=832909

[shadow191]

Looks like he went outside the tolerance by switching rear tire size. Different companies size tires slightly differently. So for him, 275 may have been just within the range, but going to 265 and stretching slightly which will drop the diameter some messed it up.

You may have a problem, you may not.

Originally Posted by JaysBlueE92

guys, this isn't about the rolling diameter as I stated. I know how to use the calculation tool for keeping the percentage in check.

I am more so concerned with my transfer case acting up because my car has adapted to the current tire setup, 235/35 and 265/30. This user had an issue I am talking about http://www.e90post.com/forums/showthread.php?t=832909

[flip4335]

Originally Posted by JaysBlueE92

guys, this isn't about the rolling diameter as I stated. I know how to use the calculation tool for keeping the percentage in check.

I am more so concerned with my transfer case acting up because my car has adapted to the current tire setup, 235/35 and 265/30. This user had an issue I am talking about http://www.e90post.com/forums/showthread.php?t=832909

But, it IS about the rolling diameter...

So, did you check to see what the 235/265 ratios look like on 19-inch rims?

According to the calculator above, 235 wheel diameter is 25.48 inches or nearly 25 and one half inches.

The 265 wheel diameter is 25.26 inches or nearly one quarter inch less in diameter.

While the specs are within one percent, the difference may adversely affect your transfer case because they are not rolling at the same revolution.

Best bet would be to have the following specs, as I said earlier:

225/35/19 Front; 265/30/19 Rear, (25.2 inch Front/25.26 inch Rear) or
235/35/19 Front; 275/30/19 Rear (25.48 inch Front/25.5 inch Rear)

235/275 are the best choice overall for x-drive. Now that you see the numbers, you can make an informed decision and the reason why any other combination will screw up the transfer case on an x-drive setup.

[WilliamS]

You keep saying what its not about. You don't understand the mechanics of the parts in questions. They do not adapt or have any indifference of what tires you have on there. As long as they have the same rolling diameter. The front and rear gears and transfer case will do the same job they always do regardless if you have a 21" tall tire or a 44" super swampers. I think you are over complicating this in your head or you really have no idea how these parts are only mechanical.

Its 100% about rolling diameters being the same, no more, no less. Overall size will have no bearing at all on what those parts do. It will only affect speedo because the car calculates speed with rotations per mile and the odometer. Unless you get a tire that wont fit, then its the body that will disagree. Quit assuming things and look at every post in this thread.

Also the thread you posted is because he did in fact have the wrong size tires as the rolling diameter did not match within the tolerance. The car doesn't care as long as they are the same height.

[VMRWheels]

OP, we are recommending those tools because we've known setups like that to work without a hitch, and when it comes down to it, it's all about the rolling diameter. If you stick within the right percentages, and pay attention to the height of the tires, you will not have a problem.

[JaysBlueE92]

Originally Posted by flip4335

But, it IS about the rolling diameter...

So, did you check to see what the 235/265 ratios look like on 19-inch rims?

According to the calculator above, 235 wheel diameter is 25.48 inches or nearly 25 and one half inches.

The 265 wheel diameter is 25.26 inches or nearly one quarter inch less in diameter.

While the specs are within one percent, the difference may adversely affect your transfer case because they are not rolling at the same revolution.

Best bet would be to have the following specs, as I said earlier:

225/35/19 Front; 265/30/19 Rear, (25.2 inch Front/25.26 inch Rear) or
235/35/19 Front; 275/30/19 Rear (25.48 inch Front/25.5 inch Rear)

235/275 are the best choice overall for x-drive. Now that you see the numbers, you can make an informed decision and the reason why any other combination will screw up the transfer case on an x-drive setup.

Thanks..i already understood this though as I have ran both the setups above on prior setups, with no problems to my transfer case. My new wheels are wider with low 20 offset in rear, hence me not able to put a 265/30 on there (or so i think, without having to roll fenders)

Originally Posted by Goofyguy

You keep saying what its not about. You don't understand the mechanics of the parts in questions. They do not adapt or have any indifference of what tires you have on there. As long as they have the same rolling diameter. The front and rear gears and transfer case will do the same job they always do regardless if you have a 21" tall tire or a 44" super swampers. I think you are over complicating this in your head or you really have no idea how these parts are only mechanical.

Its 100% about rolling diameters being the same, no more, no less. Overall size will have no bearing at all on what those parts do. It will only affect speedo because the car calculates speed with rotations per mile and the odometer. Unless you get a tire that wont fit, then its the body that will disagree. Quit assuming things and look at every post in this thread.

Also the thread you posted is because he did in fact have the wrong size tires as the rolling diameter did not match within the tolerance. The car doesn't care as long as they are the same height.

As I stated above I was confused from the other members post. It is more so about my transfer case not adapting to the new tire setup, even if it is within the recomendded thresh hold rolling diamter.

Originally Posted by VMRWheels

OP, we are recommending those tools because we've known setups like that to work without a hitch, and when it comes down to it, it's all about the rolling diameter. If you stick within the right percentages, and pay attention to the height of the tires, you will not have a problem.

i understand..and i've done the 235/35 and 265/30 on setups. I guess I shouldn't risk running the 225/35 and 255/30. THANK YOU EVERYONE for the feedback

[PSUSMU]

Originally Posted by JaysBlueE92

As I stated above I was confused from the other members post. It is more so about my transfer case not adapting to the new tire setup, even if it is within the recomendded thresh hold rolling diamter.



i understand..and i've done the 235/35 and 265/30 on setups. I guess I shouldn't risk running the 225/35 and 255/30. THANK YOU EVERYONE for the feedback

THERE'S NOTHING TO "ADAPT." 225/35 AND 255/30 IS PERFECTLY FINE ON XDRIVE. STOP BEING A SCAREDY CAT.

[JaysBlueE92]

Originally Posted by PSUSMU

THERE'S NOTHING TO "ADAPT." 225/35 AND 255/30 IS PERFECTLY ON XDRIVE. STOP BEING A SCAREDY CAT.

[PSUSMU]

I ran 225/40 and 265/35 on xDrive w/o issues.