XI Staggered Tire Calculation Tables

angrychicken · 05-09-2018, 05:38 PM

Can I get some feedback running rear spacers only?

I'm driving a newer to me 06 330xi as a grocery getter and work commuter. My track day car is down so I've used this car for an occasion autocross or HPDE event.
I'm running 17x9 +30 wheels with 245/40/17 tires. With the square set up, the front is flush but the rear has lots room to widen out the stance.

The car really understeers but I'd like to keep the suspension OEM.
I've played with tire pressures but I'm not confident I'm going to get much more from that.

Is it possible to run 5 mm spacers in the rear only to reduce understeer? There is def room for that. Or will that fuck up the x-drive?

Thanks in advance!

floydarogers · 05-09-2018, 06:29 PM

Quote:

Originally Posted by angrychicken

...

The car really understeers but I'd like to keep the suspension OEM.
I've played with tire pressures but I'm not confident I'm going to get much more from that.

Is it possible to run 5 mm spacers in the rear only to reduce understeer? There is def room for that. Or will that fuck up the x-drive?

It won't mess up the xDrive.

Best mod for understeer that I've heard about is a stiffer rear sway bar.

angrychicken · 05-09-2018, 07:54 PM

Quote:

Originally Posted by floydarogers

It won't mess up the xDrive.

Best mod for understeer that I've heard about is a stiffer rear sway bar.

Yup, but I'm trying to keep this car stock and a rear sway bar in these cars is pretty labor intensive.

Thanks!

Silp3 · 02-12-2020, 07:59 PM

Hi all,

Thread revival: I just picked up a set of 5 series wheels. Specs below. I have already mounted the wheels to my e90 xi, so they fit without rubbing.

Front 245/40/19
Rear 275/35/19

I’ve run multiple calculators and came up with .14” difference or (-0.52%)

Can any of you please check my work and confirm I will not run into AWD issues. The ride home from my warehouse after in stall didn’t give me the confident feeling I was expecting. Transmission feels less smooth and there is hesitation at part throttle. I deactivated traction fully and I didn’t notice the hesitation but I also shut off traction fully once I was on residential streets and I realized this wasn’t a fair comparison.

Any insight would be appreciated.

em5ive · 04-15-2020, 05:30 PM

Hey all,

Found this thread and looking at picking up a set of used set of staggered 18x 8.5/9 wheels. It comes with 255/40/18 square set up on all 4. I see from the stock 225/45/17 on 17x8 there is a 4.24% speedo error however a 0% difference between the front and back because of the square set up.

Beside the speedo error will there be any issues with this setup? I'm not so much worried about fitment as I'm on stock XI suspension for now.

I do plan to run a staggered 225/40 up front with 255/35 at the rear or possibly even 255/35 square, just curious is this set up can work in the meantime.

Thank you.

Nismo G · 05-10-2020, 06:24 PM

I am certainly not an expert in this area...I tried searching around and didn't find much. When I checked on tiresize.com it seems like this set up would work, but i will ask for feedback from those who are more well versed in this area.

I like the look of a fat rear tire...so will this work?
2008 E90 335XI
Front: 245/35/18 18x8.5 et38
Rear 285/30/18 18x9.5 et35

I ran a similar setup on one of my previous vehicle, except it was on 19" wheels. Personally, I really liked the overall appearance...the tire/wheel setup looked as though they came from the factory (i.e. they weren't stretched or bulging). Prior set up was on a different car all together, a Infiniti g35 coupe, but was TE37 19x8.5+22 19x9.5+22 with 245/35/19 and 285/30/19. A couple pictures below for why I liked this set up.

joshe92 · 05-29-2020, 04:27 PM

2011 xdrive coupe.
FRONT: 245/40/18
REAR: 275/35/18
According to the table, I’m within OEM spec. Anyone else running this set up or familiar with this?

tgeho_e92 · 06-25-2021, 07:51 PM

I bought my car with
F: 235/40 ZR 18
R: 245/40 ZR 18
I have been experiencing some sort of surge when on the highway. I'm 1.2% according to the chart so I'm thinking it has something to do with that? Any insights would be great!

335xirookie · 06-25-2021, 10:55 PM

Quote:

Originally Posted by joshe92

2011 xdrive coupe.
FRONT: 245/40/18
REAR: 275/35/18
According to the table, I’m within OEM spec. Anyone else running this set up or familiar with this?

see attached... no problems on PS2

05-09-2018, 05:38 PM	#133
angrychicken New Member 0 Rep 8 Posts Drives: 330xi Join Date: Jan 2018 Location: PNW iTrader: (0)	Can I get some feedback running rear spacers only? I'm driving a newer to me 06 330xi as a grocery getter and work commuter. My track day car is down so I've used this car for an occasion autocross or HPDE event. I'm running 17x9 +30 wheels with 245/40/17 tires. With the square set up, the front is flush but the rear has lots room to widen out the stance. The car really understeers but I'd like to keep the suspension OEM. I've played with tire pressures but I'm not confident I'm going to get much more from that. Is it possible to run 5 mm spacers in the rear only to reduce understeer? There is def room for that. Or will that fuck up the x-drive? Thanks in advance!
	Appreciate 0 Quote

02-12-2020, 07:59 PM	#136
Silp3 New Member 0 Rep 27 Posts Drives: e46, FRS, Silverado, e90 Join Date: Mar 2011 Location: Boston/Fort Lauderdale iTrader: (0)	Hi all, Thread revival: I just picked up a set of 5 series wheels. Specs below. I have already mounted the wheels to my e90 xi, so they fit without rubbing. Front 245/40/19 Rear 275/35/19 I’ve run multiple calculators and came up with .14” difference or (-0.52%) Can any of you please check my work and confirm I will not run into AWD issues. The ride home from my warehouse after in stall didn’t give me the confident feeling I was expecting. Transmission feels less smooth and there is hesitation at part throttle. I deactivated traction fully and I didn’t notice the hesitation but I also shut off traction fully once I was on residential streets and I realized this wasn’t a fair comparison. Any insight would be appreciated.
	Appreciate 0 Quote

04-15-2020, 05:30 PM	#137
em5ive Private First Class 102 Rep 122 Posts Drives: 2009 E91 Join Date: Jan 2019 Location: Canada iTrader: (1)	Hey all, Found this thread and looking at picking up a set of used set of staggered 18x 8.5/9 wheels. It comes with 255/40/18 square set up on all 4. I see from the stock 225/45/17 on 17x8 there is a 4.24% speedo error however a 0% difference between the front and back because of the square set up. Beside the speedo error will there be any issues with this setup? I'm not so much worried about fitment as I'm on stock XI suspension for now. I do plan to run a staggered 225/40 up front with 255/35 at the rear or possibly even 255/35 square, just curious is this set up can work in the meantime. Thank you.
	Appreciate 0 Quote

05-10-2020, 06:24 PM	#138
Nismo G Second Lieutenant 51 Rep 243 Posts Drives: 2008 335xi Sedan Join Date: Jul 2014 Location: Sarasota, FL iTrader: (1)	I am certainly not an expert in this area...I tried searching around and didn't find much. When I checked on tiresize.com it seems like this set up would work, but i will ask for feedback from those who are more well versed in this area. I like the look of a fat rear tire...so will this work? 2008 E90 335XI Front: 245/35/18 18x8.5 et38 Rear 285/30/18 18x9.5 et35 I ran a similar setup on one of my previous vehicle, except it was on 19" wheels. Personally, I really liked the overall appearance...the tire/wheel setup looked as though they came from the factory (i.e. they weren't stretched or bulging). Prior set up was on a different car all together, a Infiniti g35 coupe, but was TE37 19x8.5+22 19x9.5+22 with 245/35/19 and 285/30/19. A couple pictures below for why I liked this set up. Attached Images __________________ Current: 08 335xi Sedan - ST Suspension Coilovers - M3 Front Strut Brace - COBB Stage 1 - ECS Tuning Chargepipe + BOV - aFe Stage 2 Intake - Precision Raceworks Ignition Coils
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05-29-2020, 04:27 PM	#139
joshe92 Major 87 Rep 1,046 Posts Drives: 2017 F80 M3 Join Date: Mar 2014 Location: Detroit, MI iTrader: (-1)	2011 xdrive coupe. FRONT: 245/40/18 REAR: 275/35/18 According to the table, I’m within OEM spec. Anyone else running this set up or familiar with this?
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06-25-2021, 07:51 PM	#140
tgeho_e92 Novice Enthusiast 16 Rep 75 Posts Drives: 2010 BMW 328i e92 ULEV 90k Join Date: Apr 2021 Location: Bethlehem, Pennsylvania iTrader: (0) Garage List 2010 BMW 328i x-Drive [0.00] 2012 Ford E-350 [0.00] 2009 Cadillac DTS LUX [0.00] 2003 Mercedes Benz ... [0.00]	I bought my car with F: 235/40 ZR 18 R: 245/40 ZR 18 I have been experiencing some sort of surge when on the highway. I'm 1.2% according to the chart so I'm thinking it has something to do with that? Any insights would be great! __________________ ‘10 328i 6AT (GM 6L45) AWD ‘03 SLK 230 5AT RWD ‘09 DTS 4AT FWD 12 Ford E-350
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