Running 275/35/22 and 315/30/22

sam01 · 07-31-2019, 12:29 PM

Hi all

So I'm running the Atturo AZ850 in 275/35/22 and 315/30/22 like a few others on the forum here.

However, I noticed stumbling at WOT. I saw the posts on transfer case / ignition related stumbling. I swapped out back to the OEM wheels/tires and the stumbling "seems" to have gone away for the most part. I don't have enough time on the OEM combo yet but of the times I have gone WOT it seems to have smoothed out - maybe a super slight stumble but not 100% sure yet.

Anyone else have this occur when running this size of 22s?

andrewmr · 07-31-2019, 04:09 PM

Can't understand why different tires would cause an engine stumble.....

Unless it has something to do with the tire diameter difference. The 22's are 29.6 inch diameter and the stockers (assuming 20's) are 28.7 inch in diameter. 18's and 19's are slightly taller.

Is the car sensing the difference and retarding the timing thinking it's encountering a problem?

sam01 · 07-31-2019, 04:20 PM

The overall diameter is slightly larger than OEM. And I know that there is slight difference between front and rear with this setup. However, it is a small difference and seeing as how many on the forum here have run this size I assumed it was within BMW tolerance. My fear is that this is causing the transfer case to think there is slip on hard acceleration and then kicking in traction control systems causing the stumbling. What's worse is that if that is actually true then I cannot imagine this sizing to work in the long term for the transfer case.

Having said all that though... oddly enough I cannot find anyone on the forum complaining about these symptoms when running these sizes.

sam01 · 07-31-2019, 04:21 PM

The rims I have these mounted on are 22x10 and 22x11

duercos · 07-31-2019, 11:22 PM

Maybe it's simply because of the wheels' weight? Should be a noticeable difference with the oem ones. Plus more resistance..

sam01 · 08-01-2019, 09:54 AM

The weight difference should just decrease performance though? I don't see it causing a stumble.

sj22 · 08-01-2019, 12:20 PM

Are your oem star marked?

The 22s might not be equal in size/wear.

sam01 · 08-01-2019, 12:50 PM

Quote:

Originally Posted by sj22

Are your oem star marked?

The 22s might not be equal in size/wear.

What is "star marked"?

The 22s are the same set up a number of others are running on here. The Atturo AZ850s. On page one right now there is a dedicated link with feedback from others running these in 22s and that exact size.

sj22 · 08-01-2019, 06:12 PM

Quote:

Originally Posted by sam01

What is "star marked"?

The 22s are the same set up a number of others are running on here. The Atturo AZ850s. On page one right now there is a dedicated link with feedback from others running these in 22s and that exact size.

https://www.google.com/search?q=star+marked+tires

Size tolerance means nothing when there is uneven wear - are your atturos new? Basically if one of your tire is more worn, the 2-3% size difference between axles might end up being 3-4% just because of the wear.

I had similar issues on my 750.

If you have a 2014-15, I wouldn't advise going down this road.

sam01 · 08-01-2019, 10:03 PM

Quote:

Originally Posted by sj22

https://www.google.com/search?q=star+marked+tires

Size tolerance means nothing when there is uneven wear - are your atturos new? Basically if one of your tire is more worn, the 2-3% size difference between axles might end up being 3-4% just because of the wear.

I had similar issues on my 750.

If you have a 2014-15, I wouldn't advise going down this road.

The tires were brand new. Maybe 400-600 kms on them so far since I got them.

The tires are nowhere near 2-3% difference front and rear with this set up. Front comes in at 29.58" overall diameter and rear comes in at 29.44" overall diameter. We're talking 0.14" difference front to rear.

Plus not to mention there are many who are running this setup on the forums. This whole thing has me puzzled.

How come you mentioned 2014-15 model years specifically and left out the 2016-18 years?

sam01 · 08-01-2019, 10:08 PM

Update: took the X5 for a run around the freeway today. I can definitely confirm no stumbling on the OEM rims/tires.

Guess, I'll put the 22s back on this weekend and try them again. Maybe by some sliver of a chance the stumbling was intermittent and happened to go away at the same time I swapped the OEM rims back on?

sam01 · 08-01-2019, 10:24 PM

Quote:

Originally Posted by andrewmr

Can't understand why different tires would cause an engine stumble.....

Unless it has something to do with the tire diameter difference. The 22's are 29.6 inch diameter and the stockers (assuming 20's) are 28.7 inch in diameter. 18's and 19's are slightly taller.

Is the car sensing the difference and retarding the timing thinking it's encountering a problem?

I've done the over sized wheel/tire combo on many of my cars. Never had any issues. I don't know of any sensor where the ECU would know that the overall diameter has changed. The sensors only detect revolutions on a rim and not how much distance on the road that rim/tire combo traveled with that revolution. Performance aside, all this causes is the speedometer to be off slightly.

Gtz1wickedest · 08-01-2019, 11:53 PM

Quote:

Originally Posted by sam01

Update: took the X5 for a run around the freeway today. I can definitely confirm no stumbling on the OEM rims/tires.

Guess, I'll put the 22s back on this weekend and try them again. Maybe by some sliver of a chance the stumbling was intermittent and happened to go away at the same time I swapped the OEM rims back on?

Be careful not to damage the transfer case don't go far from home if anything happens make sure u put the oem wheels on then take it to the dealer (talking from experience on my 3rd transfer case and second driveshaft all covered under warranty but ONLY with oem wheels)

histandards · 08-14-2019, 08:03 AM

hey man. im about to pull the trigger on my 22 setup and looking at this exact tire setup too. Did you ever determine if it was the wheels?

sam01 · 08-17-2019, 04:37 PM

I haven't been able to figure it out yet. So far the theory is that it could be linked to a muffler delete and that the ECU isn't compensating enough under the load of WOT. Perhaps when I put the OEM wheels back on the weight difference/reduced load makes the stumbling less harsh. But today I finally got around to putting the 22s back on and noticed it was about the same as the OEM wheels now. OEM wheels ended up with slight stumble but definitely less harsh. Maybe it is because the muffler delete needs a tune to run smooth. Not completely sure at all but just a guess at this point.

sam01 · 09-09-2019, 05:25 PM

Update: Been running on the 22s for some time now. It seemed to be running a little smoother and I got comfortable with the size difference between front and rear since the OEM 21" setup from BMW actually has larger front to rear differences than this 22" setup.

Anyways, it was running better for a while. Under certain throttle positions there was a bit of stumble. Then last week the stumble started to come back. A few days ago the drivetrain malfunction light came on and the car was stumbling very hard. Even at idle it was missing and was actually causing the car to rock. This actually came as a relief since it then ruled out transfer case issues since it was missing at idle.

BMW had the vehicle today and the light wasn't on but they traced the light to cylinder 3. During a test drive the tech was able to reproduce the stumble and has now replaced coil and plug for cylinder 3. I haven't picked up the car yet but will give another update once I get the car back and drive it around.

pennsiveguy · 09-10-2019, 02:10 PM

How's the car running now, since you got it back with the new plug and coil? Reading through the thread, my hunch was that the timing of the stumble was just a coincidence and not connected to the tire swap in any way. Hope you got it straightened out.

sam01 · 09-10-2019, 05:03 PM

The car is running better for sure. I'm not sure if it was just in my head but perhaps there's still a tiny bit of stumbling? I only had time for a short drive home. I don't drive it everyday so once I get a chance to really get on it I'll come back for another update. However, if it helps I don't expect there to be any remaining issue (pretty sure if I felt something it was just in my head).

mrod81 · 09-10-2019, 07:05 PM

Ive put in bigger wheels on all my cars never had an issue like what you're having. I highly doubt its the wheels. Im running 22s pretty much since I bought my X5 with ZERO issues.

aligazi · 09-10-2019, 09:19 PM

Its the transfer case, had it happen on my x5 with 22s.

sam01 · 09-18-2019, 12:57 PM

Update

Runs smooth now. No issues. It was an ignition problem but didn't throw codes until it failed hard enough to cause the car to rock during idle.

Under full throttle it failed (without code) to the point where it felt like someone was stepping on the brakes during acceleration.

Once the coil and plug was replaced it ran smooth again.

07-31-2019, 12:29 PM	#1
sam01 Enlisted Member 45 Rep 38 Posts Drives: X5 50i Join Date: Dec 2014 Location: Canada iTrader: (0)	Running 275/35/22 and 315/30/22 - Stumbling on hard acceleration Hi all So I'm running the Atturo AZ850 in 275/35/22 and 315/30/22 like a few others on the forum here. However, I noticed stumbling at WOT. I saw the posts on transfer case / ignition related stumbling. I swapped out back to the OEM wheels/tires and the stumbling "seems" to have gone away for the most part. I don't have enough time on the OEM combo yet but of the times I have gone WOT it seems to have smoothed out - maybe a super slight stumble but not 100% sure yet. Anyone else have this occur when running this size of 22s?
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07-31-2019, 04:09 PM	#2
andrewmr Second Lieutenant 449 Rep 287 Posts Drives: 2020 M4 Join Date: Aug 2014 Location: Bucks County PA. iTrader: (0) Garage List 2020 BMW / F82 [0.00] 2016 BMW X5 35i [0.00] 2012 Porsche 991 C2S [0.00] 2013 Audi S8 [0.00] 2004 Ferrari Challe ... [0.00]	Can't understand why different tires would cause an engine stumble..... Unless it has something to do with the tire diameter difference. The 22's are 29.6 inch diameter and the stockers (assuming 20's) are 28.7 inch in diameter. 18's and 19's are slightly taller. Is the car sensing the difference and retarding the timing thinking it's encountering a problem?
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07-31-2019, 04:20 PM	#3
sam01 Enlisted Member 45 Rep 38 Posts Drives: X5 50i Join Date: Dec 2014 Location: Canada iTrader: (0)	The overall diameter is slightly larger than OEM. And I know that there is slight difference between front and rear with this setup. However, it is a small difference and seeing as how many on the forum here have run this size I assumed it was within BMW tolerance. My fear is that this is causing the transfer case to think there is slip on hard acceleration and then kicking in traction control systems causing the stumbling. What's worse is that if that is actually true then I cannot imagine this sizing to work in the long term for the transfer case. Having said all that though... oddly enough I cannot find anyone on the forum complaining about these symptoms when running these sizes.
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07-31-2019, 04:21 PM	#4
sam01 Enlisted Member 45 Rep 38 Posts Drives: X5 50i Join Date: Dec 2014 Location: Canada iTrader: (0)	The rims I have these mounted on are 22x10 and 22x11
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07-31-2019, 11:22 PM	#5
duercos Lieutenant 201 Rep 413 Posts Drives: F36>F16>G30 Join Date: Oct 2016 Location: Hillsborough, NJ iTrader: (0)	Maybe it's simply because of the wheels' weight? Should be a noticeable difference with the oem ones. Plus more resistance..
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		BMW X5 and X6 Forum (F15/F16) > BMW X5 (F15) and BMW X6 (F16) Forum > BMW X5 and X6 (F15/F16) Forum
Running 275/35/22 and 315/30/22 - Stumbling on hard acceleration

08-01-2019, 09:54 AM	#6
sam01 Enlisted Member 45 Rep 38 Posts Drives: X5 50i Join Date: Dec 2014 Location: Canada iTrader: (0)	The weight difference should just decrease performance though? I don't see it causing a stumble.
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08-01-2019, 12:20 PM	#7
sj22 Lieutenant 197 Rep 535 Posts Drives: 14 F15 50I Join Date: Nov 2011 Location: Vancouver iTrader: (1)	Are your oem star marked? The 22s might not be equal in size/wear.
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08-01-2019, 10:08 PM	#11
sam01 Enlisted Member 45 Rep 38 Posts Drives: X5 50i Join Date: Dec 2014 Location: Canada iTrader: (0)	Update: took the X5 for a run around the freeway today. I can definitely confirm no stumbling on the OEM rims/tires. Guess, I'll put the 22s back on this weekend and try them again. Maybe by some sliver of a chance the stumbling was intermittent and happened to go away at the same time I swapped the OEM rims back on?
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08-14-2019, 08:03 AM	#14
histandards Enlisted Member 44 Rep 41 Posts Drives: 2015 X5 35i M-Sport Join Date: Jan 2015 Location: Boston MA iTrader: (0)	hey man. im about to pull the trigger on my 22 setup and looking at this exact tire setup too. Did you ever determine if it was the wheels?
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08-17-2019, 04:37 PM	#15
sam01 Enlisted Member 45 Rep 38 Posts Drives: X5 50i Join Date: Dec 2014 Location: Canada iTrader: (0)	I haven't been able to figure it out yet. So far the theory is that it could be linked to a muffler delete and that the ECU isn't compensating enough under the load of WOT. Perhaps when I put the OEM wheels back on the weight difference/reduced load makes the stumbling less harsh. But today I finally got around to putting the 22s back on and noticed it was about the same as the OEM wheels now. OEM wheels ended up with slight stumble but definitely less harsh. Maybe it is because the muffler delete needs a tune to run smooth. Not completely sure at all but just a guess at this point.
	Appreciate 0 Quote

09-09-2019, 05:25 PM	#16
sam01 Enlisted Member 45 Rep 38 Posts Drives: X5 50i Join Date: Dec 2014 Location: Canada iTrader: (0)	Update: Been running on the 22s for some time now. It seemed to be running a little smoother and I got comfortable with the size difference between front and rear since the OEM 21" setup from BMW actually has larger front to rear differences than this 22" setup. Anyways, it was running better for a while. Under certain throttle positions there was a bit of stumble. Then last week the stumble started to come back. A few days ago the drivetrain malfunction light came on and the car was stumbling very hard. Even at idle it was missing and was actually causing the car to rock. This actually came as a relief since it then ruled out transfer case issues since it was missing at idle. BMW had the vehicle today and the light wasn't on but they traced the light to cylinder 3. During a test drive the tech was able to reproduce the stumble and has now replaced coil and plug for cylinder 3. I haven't picked up the car yet but will give another update once I get the car back and drive it around.
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09-10-2019, 02:10 PM	#17
pennsiveguy Major 3552 Rep 1,062 Posts Drives: F15 xDrive50i M-sport Join Date: Apr 2019 Location: Edina, MN iTrader: (0) Garage List 2017 BMW X5 xDrive50i [0.00]	How's the car running now, since you got it back with the new plug and coil? Reading through the thread, my hunch was that the timing of the stumble was just a coincidence and not connected to the tire swap in any way. Hope you got it straightened out. __________________ 2017 F15 xDrive50i M Sport \| Superformance GT40 Roush 511 IR FE
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09-10-2019, 05:03 PM	#18
sam01 Enlisted Member 45 Rep 38 Posts Drives: X5 50i Join Date: Dec 2014 Location: Canada iTrader: (0)	The car is running better for sure. I'm not sure if it was just in my head but perhaps there's still a tiny bit of stumbling? I only had time for a short drive home. I don't drive it everyday so once I get a chance to really get on it I'll come back for another update. However, if it helps I don't expect there to be any remaining issue (pretty sure if I felt something it was just in my head).
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09-10-2019, 07:05 PM	#19
mrod81 Second Lieutenant 208 Rep 258 Posts Drives: BMW F15 Join Date: Jan 2019 Location: San Diego iTrader: (0)	Ive put in bigger wheels on all my cars never had an issue like what you're having. I highly doubt its the wheels. Im running 22s pretty much since I bought my X5 with ZERO issues.
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09-10-2019, 09:19 PM	#20
aligazi Private 24 Rep 79 Posts Drives: 2010 Join Date: Mar 2014 Location: nyc iTrader: (0)	Its the transfer case, had it happen on my x5 with 22s.
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09-18-2019, 12:57 PM	#21
sam01 Enlisted Member 45 Rep 38 Posts Drives: X5 50i Join Date: Dec 2014 Location: Canada iTrader: (0)	Update Runs smooth now. No issues. It was an ignition problem but didn't throw codes until it failed hard enough to cause the car to rock during idle. Under full throttle it failed (without code) to the point where it felt like someone was stepping on the brakes during acceleration. Once the coil and plug was replaced it ran smooth again.
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