[WRS_ATL]

Hi. I'm new to this forum and have yet to find a definitive answer to this question. In a U.S. spec 2022 M240i, I understand that selecting the Cooling and High Performance Tire Package will result in the addition of the "fender flares". That package comes with 893M wheels that are 19 x 8.5 in the front (w/ 245/35 19s) and 19x9.5 in the rear (w/ 255/35 R19s).

My order does not include the Cooling and High Performance Tire Package but it does include 19" M Double spoke cerium gray style 792, w/performance non run flat tires, which have the exact same dimensions (and tires) as the 893Ms.... 19 x 8.5 in the front (w/ 245/35 19s) and 19x9.5 in the rear (w/ 255/35 R19s).

So my question is: will my order come with fender flares? If the flares are only added for the Cooling and High Performance Tire package, then the answer is "no". However, if the fender flares are affiliated with wider tires (presumably for some regulation), then it seems like they would be added.

Anyone with the 792s (NOT 792 Ms, which are narrower) on here that can tell me? Or anyone that just knows the answer.

Thanks!

[WRS_ATL]

P.S. On the BMWUSA build site, adding 792s does not show the fender flares, but I don't trust that site. (E.g., changing between 792s and 792Ms on the site does not change the width of the tires, but it should, so at least that is in error.)

[mechman]

Originally Posted by WRS_ATL

Hi. I'm new to this forum and have yet to find a definitive answer to this question. In a U.S. spec 2022 M240i, I understand that selecting the Cooling and High Performance Tire Package will result in the addition of the "fender flares". That package comes with 893M wheels that are 19 x 8.5 in the front (w/ 245/35 19s) and 19x9.5 in the rear (w/ 255/35 R19s).

My order does not include the Cooling and High Performance Tire Package but it does include 19" M Double spoke cerium gray style 792, w/performance non run flat tires, which have the exact same dimensions (and tires) as the 893Ms.... 19 x 8.5 in the front (w/ 245/35 19s) and 19x9.5 in the rear (w/ 255/35 R19s).

So my question is: will my order come with fender flares? If the flares are only added for the Cooling and High Performance Tire package, then the answer is "no". However, if the fender flares are affiliated with wider tires (presumably for some regulation), then it seems like they would be added.

Anyone with the 792s (NOT 792 Ms, which are narrower) on here that can tell me? Or anyone that just knows the answer.

Thanks!

Its an error on the US order guide. Only the 893's come with 245 Fronts.

A few of us spec'd our cars with 1VZ. I will be picking up my car in 2 weeks but others who have gotten theirs already confirmed that the car did come with the 225 Fronts even for the 792 with Performance non RFT.

There is a detailed discussion on this topic in the link below:

https://g42.bimmerpost.com/forums/sh....php?t=1896883

[XC3LLR8]

I'd be shocked if the fender flares are based on a regulation, as even with the wider wheels and wider front tires (back tires same size) they still sit embarrassingly far inside the fender.

[WRS_ATL]

Thanks MechMan, that is news to me. So are the 792 rears 255? (Hopefully not 225s all around.)

Man, my sales advisor sucks.

[mechman]

Originally Posted by WRS_ATL

Thanks MechMan, that is news to me. So are the 792 rears 255? (Hopefully not 225s all around.)

Man, my sales advisor sucks.

Trust me, yours is not the only one that sucks.

Correct. The 792's on the 1VZ come in 19x8Front (225/40-19) and 19x8.5Rear (255/35-19) with this option.

I plan to discard the 225 in the front and upsize it to a 245/35-19 on the 19x8 wheel.

[Roadwar]

I for one am glad not to have the "baby flares". All you old guys will know what I'm talking about when I call them fender spats. Pretty useless to widen the fender when the tires don't stick out any way. Mechman, I'm with you on the tire change out. I wiil swap the Pirellis for some Michelins (larger on the front) soon.

[XC3LLR8]

Originally Posted by Roadwar

I for one am glad not to have the "baby flares". All you old guys will know what I'm talking about when I call them fender spats. Pretty useless to widen the fender when the tires don't stick out any way. Mechman, I'm with you on the tire change out. I wiil swap the Pirellis for some Michelins (larger on the front) soon.

To me the non-fender flare looks unfinished after seeing it with the fender flares. The whole package comes together when you slap 255's on the front and 275's on the rear and finish it off with a mild spacer.

[danallxt]

hummm, looks like I'm not the only one trusting the North America Order Guide. The Order Guide needs a subheading "Information contained herewith may or may not be factually correct"

[verysideways]

Originally Posted by mechman

Trust me, yours is not the only one that sucks.

Correct. The 792's on the 1VZ come in 19x8Front (225/40-19) and 19x8.5Rear (255/35-19) with this option.

I plan to discard the 225 in the front and upsize it to a 245/35-19 on the 19x8 wheel.

Be careful doing that.

The reason the 245/255 package comes with additional transmission cooling is so the transfer case can cope with the increased heat from running the 245/255 set up.

The 225/255 set up has the same rolling radius front to rear hence does not need the additional transmission cooling option.

[XC3LLR8]

Originally Posted by verysideways

Be careful doing that.

The reason the 245/255 package comes with additional transmission cooling is so the transfer case can cope with the increased heat from running the 245/255 set up.

The 225/255 set up has the same rolling radius front to rear hence does not need the additional transmission cooling option.

I've never heard of extra transmission cooling requirements for going up 1 or 2 sizes in tire width. We're only talking 0.39" per front tire in this case.

[SupraCooper]

I can confirm on the 792m wheels are 225 front and 255 rears. I been waiting for just an allocation since November and a truck with a couple m240s had to come by today to drop one car off and tease me

[verysideways]

Originally Posted by XC3LLR8

I've never heard of extra transmission cooling requirements for going up 1 or 2 sizes in tire width. We're only talking 0.39" per front tire in this case.

But it's not the width, it's the rolling radius, and in this case it's due to the requirements of the 4wd system.

For the rwd bias to be accentuated there's software involved in running the clutch pack "over open", which also increases the cooling requirements.

It's a similar set up to the M5 running in 2wd instead of 4wd.

I'm not saying don't do it, I'm saying be aware of the risks you're taking with your xdrive system by doing this.

[Floxy]

Based on all I’ve seen you have to get the cooling and high performance tire package to get the flares. I was on the fence with the package (BMW sucks at marketing them) but glad I opted for it.

[mechman]

Originally Posted by verysideways

But it's not the width, it's the rolling radius, and in this case it's due to the requirements of the 4wd system.

For the rwd bias to be accentuated there's software involved in running the clutch pack "over open", which also increases the cooling requirements.

It's a similar set up to the M5 running in 2wd instead of 4wd.

I'm not saying don't do it, I'm saying be aware of the risks you're taking with your xdrive system by doing this.

Isn't the additional cooler in the HP & cooling pkg for extra engine oil cooling due to being more of a track focused package? I didnt think it had anything to do with the transfer case cooling.

I did verify the rolling radius and its a 0.8% difference in 245/35-19 vs 255/35-19 compared to 0.4% difference for 225/40-19 vs 255/35-19.

[danallxt]

IF a change in tire size such as offered with the ZTK package could lead to premature x drive failure (if w/o the cooling package), it seems that BMW would have a disclaimer that with non ZTK option cars a change in tire size could invalidate the warranty and lead to premature drivetrain failure? Especially since it is not uncommon for folks to be changing tire sizes on these types of cars. Also for BMW to engineer something so close to margins of failure that a very small change in tire rolling radius could lead to failure seems like poor engineering.

[XC3LLR8]

Take a look at differences in tread width amongst exact same tires, but one with a manufacturer's spec. The Michelin PS4S in 245 with the BMW spec has a tread width of 6.8", while the 245 in non-BMW spec has a tread width of 8.6". Do most people even know to order tires in a "BMW spec" vs. just ordering the tire? That alone can blow-out the rolling radius theory.

[danallxt]

Originally Posted by XC3LLR8

Take a look at differences in tread width amongst exact same tires, but one with a manufacturer's spec. The Michelin PS4S in 245 with the BMW spec has a tread width of 6.8", while the 245 in non-BMW spec has a tread width of 8.6". Do most people even know to order tires in a "BMW spec" vs. just ordering the tire? That alone can blow-out the rolling radius theory.

change in tread width will not affect rolling radius. Aspect ratio will (35 vs 40).

[XC3LLR8]

Originally Posted by danallxt

change in tread width will not affect rolling radius. Aspect ratio will (35 vs 40).

Yeah, not sure why I missed that? We're talking tire height and not rolling resistance, and neither one would require an engine oil cooler.

[Floxy]

Originally Posted by XC3LLR8

I've never heard of extra transmission cooling requirements for going up 1 or 2 sizes in tire width. We're only talking 0.39" per front tire in this case.

+1. No way two extra tire sizes is the reason for extra cooling

[verysideways]

Originally Posted by danallxt

change in tread width will not affect rolling radius. Aspect ratio will (35 vs 40).

You do understand that aspect ratio isn't absolute, and that it's a percentage of tread width right?

[verysideways]

Originally Posted by mechman

Isn't the additional cooler in the HP & cooling pkg for extra engine oil cooling due to being more of a track focused package? I didnt think it had anything to do with the transfer case cooling.

I did verify the rolling radius and its a 0.8% difference in 245/35-19 vs 255/35-19 compared to 0.4% difference for 225/40-19 vs 255/35-19.

Errr, rolling radius difference between a 225/40R19 and 255/35R19 is 0.23%, the difference between a 245/35R19 and a 255/35R19 is 1.07%
(and for completeness the difference between the 225/40R19 and 245/35R19 is 1.3%).

BMW have specified a 1% tolerance for their Xdrive systems for years, way back to the E83 X3 and E53 X5 - hence the reason for additional transmission cooling to run a larger than 1% difference between axles (standard on the M5 and M8 which are able to run in 2wd mode by using the same principle, enabling the clutch pack to run "over open").

Don't take my word for it, do your own research.

In most countries BMW reject warranty claims on xdrive transmissions if you've ignored the 1% limitation. Perhaps they're more lenient in North America, but those are the rules for the rest of us.