[ThirstyX3M]

I have a set of bc forged wheels that came off my Audi sq5. Specs are 21x10 et 33 front/ et 30 rear. I’d love to be able to run these on the X3M but unsure what spacers I’d need to caliper clearance and have a flush fitment with 265/40 & 295/35 tire setup. I’m currently running oem 892M wheels with 12mm spacers all around and lowered on MSS springs. Any help would be much appreciated! TIA

[Johnzi]

I forget the name but there's a site that lets you put stock rim size and offset, then input new rim size and offset.

Tells you if it works or need spacers etc.

Maybe someone else knows the actual name lol

[TacosRule!]

Originally Posted by Johnzi

I forget the name but there's a site that lets you put stock rim size and offset, then input new rim size and offset.

Tells you if it works or need spacers etc.

Maybe someone else knows the actual name lol

https://www.wheel-size.com/calc/


https://www.willtheyfit.com/

[BrockDM]

With a 21x10, you'll need at least an effective offset of et25 in the front to clear the suspension side. Ideally I like et23 for a little more clearance.

So up front 10mm spacer and in the rear I would do an 8mm to put them flush with each other.

Here is a 20x10 et23 front and et25 rear.

[TacosRule!]

Originally Posted by BrockDM

With a 21x10, you'll need at least an effective offset of et25 in the front to clear the suspension side. Ideally I like et23 for a little more clearance.

So up front 10mm spacer and in the rear I would do an 8mm to put them flush with each other.

Here is a 20x10 et23 front and et25 rear.

Damn, what size rubber is that running? Does it rub on full lock?

[BrockDM]

Originally Posted by saabster2010

Damn, what size rubber is that running? Does it rub on full lock?

I'm running 275/40/20 squared. I've never rubbed

[TacosRule!]

Originally Posted by BrockDM

I'm running 275/40/20 squared. I've never rubbed

wow, great work. Now I reeeeeally want to move to 789Ms

[ThirstyX3M]

Originally Posted by BrockDM

With a 21x10, you'll need at least an effective offset of et25 in the front to clear the suspension side. Ideally I like et23 for a little more clearance.

So up front 10mm spacer and in the rear I would do an 8mm to put them flush with each other.

Here is a 20x10 et23 front and et25 rear.

Right on, much appreciated! Looks mean with that fitment! How do you think that would play without being as low as you are, also hoping to run 265/40 & 295/35. Thanks for the info and suggestions!

[BrockDM]

Originally Posted by ThirstyX3M

Right on, much appreciated! Looks mean with that fitment! How do you think that would play without being as low as you are, also hoping to run 265/40 & 295/35. Thanks for the info and suggestions!

It will still be just as flush and no risk of rubbing. I ran that same tire combo on slightly different spec of 21" wheels but effectively the same fitment and had zero problems. It will look awesome!

[ThirstyX3M]

Originally Posted by BrockDM

It will still be just as flush and no risk of rubbing. I ran that same tire combo on slightly different spec of 21" wheels but effectively the same fitment and had zero problems. It will look awesome!

Great to know! I really appreciate your time and info, looking forward to getting them put back to use! Thank you!

[BrockDM]

Originally Posted by ThirstyX3M

Great to know! I really appreciate your time and info, looking forward to getting them put back to use! Thank you!

Not a problem! Do share photos when you do, those are gorgeous!

[ThirstyX3M]

Originally Posted by BrockDM

Not a problem! Do share photos when you do, those are gorgeous!

Thanks! Will do, for sure!

[KayTees]

Originally Posted by BrockDM

I'm running 275/40/20 squared. I've never rubbed

I run 285/35/21 on the fronts and they rub just a bit

[TacosRule!]

Originally Posted by BrockDM

I'm running 275/40/20 squared. I've never rubbed

Question, did you try fitting 275/45/20 on those 20x10?

[BrockDM]

Originally Posted by saabster2010

Question, did you try fitting 275/45/20 on those 20x10?

No I haven't. It would fit fine on the wheel but thats 2.5% larger than stock. No go for me personally. 275/40/20 has a bigger selection of tires too.

[TacosRule!]

Originally Posted by BrockDM

No I haven't. It would fit fine on the wheel but thats 2.5% larger than stock. No go for me personally. 275/40/20 has a bigger selection of tires too.

So maybe you can help me figure out how to fit 789Ms. These are the specs for the front wheel

** FRONT **
Product: Wheel/Rim (Single)
Fitment: Front
Material: Forged Aluminum
Style: 10 Y Spoke
Finish: Gold Bronze
Size: 20x9.5
Lugs: 5
Bolt Pattern: 112mm
Offset: 28mm
Option Code: Style 789M
OE Part Number: 36119501872


Using the calculator here and comparing them to my OE 764M fronts (20x9), with a 275-40-20 tire

https://www.wheel-size.com/calc/?whe...cl=30mm&sr=0mm


The front 789M (20x9.5) in my 2022 X3M is:

Suspension
Tire 10mm closer to suspension components. Rim 6mm closer to suspension components. Acceptable for most cars

Fenders
Tire stick out 10mm farther. Rim will stick out 6mm farther. Acceptable for most cars

Wheel Wells
Wheel fills out wheel well by extra 9 mm. Acceptable for most cars

Brakes
The same

Scrub Radius
Negative scrub radius ~-3mm. Almost no difference. Calculated value is approximate.

Personally, I dont like the numbers. Is this 789M out of the question?

[TacosRule!]

Conversely, using the front 20x9.5 789M rims (28mm offset) in the rears with the same 275-40-20 and 11MM spacers:

11 MM (TOTAL 39 MM OFFSET, SAME AS OE 764M)

Suspension
Tire is 5 mm closer to suspension components. Acceptable for most cars

Fenders
The tire will stick out 5 mm farther. Acceptable for most cars

Wheel Wells
100% clear (leaves even more room than OE)

Brakes
SAME AS OE

Scrub Radius
Positive scrub radius (about 3 mm). Almost no difference. Please be aware that calculated value is approximate.

This feels perfect. I want the same numbers in the front...

[BrockDM]

Originally Posted by saabster2010

Conversely, using the front 20x9.5 789M rims (28mm offset) in the rears with the same 275-40-20 and 11MM spacers:

11 MM (TOTAL 39 MM OFFSET, SAME AS OE 764M)

Suspension
Tire is 5 mm closer to suspension components. Acceptable for most cars

Fenders
The tire will stick out 5 mm farther. Acceptable for most cars

Wheel Wells
100% clear (leaves even more room than OE)

Brakes
SAME AS OE

Scrub Radius
Positive scrub radius (about 3 mm). Almost no difference. Please be aware that calculated value is approximate.

This feels perfect. I want the same numbers in the front...

Yep exactly that. So if they are 20x9.5 et28 squared. I would run 10-11mm spacers all around. This will put them at 20x9.5 et17 or et18 effectively which is a perfect fit.

With 9.5 wide you dont have to worry about suspension clearance as much. On the fender side they'll be flush with a tiny bit of poke.

Those paired with 275/40/20 are perfect.

Ironically enough, my dad runs those exact specs on his X3M for winter. And I run the same on the front if my car.

Neuspeed RSe102
20x9.5 et25 with 8mm spacers (effectively et17
275/40/20 Vredstein winters

[TacosRule!]

Originally Posted by BrockDM

Yep exactly that. So if they are 20x9.5 et28 squared. I would run 10-11mm spacers all around. This will put them at 20x9.5 et17 or et18 effectively which is a perfect fit.

With 9.5 wide you dont have to worry about suspension clearance as much. On the fender side they'll be flush with a tiny bit of poke.

Those paired with 275/40/20 are perfect.

Ironically enough, my dad runs those exact specs on his X3M for winter. And I run the same on the front if my car.

Neuspeed RSe102
20x9.5 et25 with 8mm spacers (effectively et17
275/40/20 Vredstein winters

Thanks again, that's a gorgeous stance. Help me understand tho, if I add 11mm spacers to 28mm offset, wouldnt that make them 39mm offset? The numbers on that calculator freak me out. Or is the calculator wrong?

[TacosRule!]

If I run the calculator and put the front 789M stock on the front without spacers, it looks like this. What do you think?

[BrockDM]

Originally Posted by saabster2010

Thanks again, that's a gorgeous stance. Help me understand tho, if I add 11mm spacers to 28mm offset, wouldnt that make them 39mm offset? The numbers on that calculator freak me out. Or is the calculator wrong?

Adding spacers will reduce the offset of the wheel. The back pad that touches the hub of the car dictates your offest. A thicker pad will have a lower positive offset, while a thinner back pad will have a higher positive offset.

Think of the wheel spacer like it's adding material onto that back back so you would be lowering the offset even more. So a 20x9.5 et18 wheel will fit the same as a 20x9.5 et28 wheel with a 10mm spacer.

Regarding your next post; 20x9.5 et28 will likely work however I personally think they look a little too sunken into the wheel well for me. Up to you!

[TacosRule!]

Originally Posted by BrockDM

Adding spacers will reduce the offset of the wheel. The back pad that touches the hub of the car dictates your offest. A thicker pad will have a lower positive offset, while a thinner back pad will have a higher positive offset.

Think of the wheel spacer like it's adding material onto that back back so you would be lowering the offset even more. So a 20x9.5 et18 wheel will fit the same as a 20x9.5 et28 wheel with a 10mm spacer.

Regarding your next post; 20x9.5 et28 will likely work however I personally think they look a little too sunken into the wheel well for me. Up to you!

Thank you for your patience. I am an ignoramous when it comes to wheels. I've never done aftermarkets at all, so its a learning curve for me.

11mm it is!