Mismatched Tire Heights

3002 tii · 09-13-2015, 10:50 PM

If I run taller tires up front (235/40-18 vs 255/35-18), will I constantly be setting off DSC?

Westersund · 09-14-2015, 02:25 AM

Don't know how wide you wheels are (I put in 8" front and 9" rear) but it won't trigger the DSC. I think the difference have to be 4% or above for the DSC to trigger, the specs you stated are only 1,5% difference in front vs rear.

http://www.willtheyfit.com/index.php...et2=35#content

3002 tii · 09-14-2015, 03:26 AM

Quote:

Originally Posted by Westersund

Don't know how wide you wheels are (I put in 8" front and 9" rear) but it won't trigger the DSC. I think the difference have to be 4% or above for the DSC to trigger, the specs you stated are only 1,5% difference in front vs rear.

http://www.willtheyfit.com/index.php...et2=35#content

I should've been more specific but I was referring to tire height, not width.

235/40-18 = 25.3"
255/35-18 = 25.0"

Westersund · 09-14-2015, 03:39 AM

Quote:

Originally Posted by 3002 tii

I should've been more specific but I was referring to tire height, not width.

235/40-18 = 25.3"
255/35-18 = 25.0"

Put in all the correct values in the URL I provided and you will see the difference, if the circumference difference (front to rear) is below 4% you'll be fine. And the width of the rims and tires do matter in calculating the circumference, not only the height of the rim and tire.

3002 tii · 09-14-2015, 03:51 AM

Quote:

Originally Posted by Westersund

Put in all the correct values in the URL I provided and you will see the difference, if the circumference difference (front to rear) is below 4% you'll be fine. And the width of the rims and tires do matter in calculating the circumference, not only the height of the rim and tire.

I did click on the URL but I don't see how rim width makes a difference. I tried 3 different widths (9, 9.5 and 10") and the height was same each time (and I never mentioned using different diameter or height rims). Either way it seems like you answered my question.

Westersund · 09-14-2015, 04:00 AM

Quote:

Originally Posted by 3002 tii

I did click on the URL but I don't see how rim width makes a difference. I tried 3 different widths (9, 9.5 and 10") and the height was same each time (and I never mentioned using different diameter or height rims). Either way it seems like you answered my question.

A wider rim, without a wider tire will stretch the tire making the circumference smaller. Seems like the calculator doesn't take into account for a stretched tire.

Daemonblitz · 09-14-2015, 07:27 AM

You will not set off lights.

dc_wright · 09-14-2015, 07:00 PM

I've been running 255/35 x 18 (25.0" diameter) up front, and 275/35 x 18 (25.6" diameter) in the rear. I've done a couple track sessions and to date the only time DSC came on was when I hit some coolant the car ahead of me vented in a tight, medium speed curve, and I suspect DSC would have been triggered there regardless of tire diameter.

09-13-2015, 10:50 PM	#1
3002 tii Lieutenant General 2282 Rep 12,565 Posts Drives: Z4 M, X5, GX460 Join Date: Apr 2008 Location: CT iTrader: (99) Garage List F15 X5 xDrive35i [8.75] E86 Z4 M [10.00] F10 550i (Retired) [9.17] F25 X3 xDrive35i (R ... [9.43] E82 135is (Retired) [9.50] E85 Z4 M (Retired) [9.41] E90 328i xDrive (Re ... [9.25] E86 Z4 3.0si (Retired) [9.22]	Mismatched Tire Heights If I run taller tires up front (235/40-18 vs 255/35-18), will I constantly be setting off DSC? __________________ Follow for latest mods
	Appreciate 0 Tweet Quote

09-14-2015, 02:25 AM	#2
Westersund Captain 496 Rep 874 Posts Drives: BMW Join Date: Nov 2011 Location: Hallstahammar iTrader: (1)	Don't know how wide you wheels are (I put in 8" front and 9" rear) but it won't trigger the DSC. I think the difference have to be 4% or above for the DSC to trigger, the specs you stated are only 1,5% difference in front vs rear. http://www.willtheyfit.com/index.php...et2=35#content
	Appreciate 0 Quote

09-14-2015, 07:27 AM	#7
Daemonblitz Commander 221 Rep 850 Posts Drives: Z4MC/M5/640iX/M1000RR Join Date: Nov 2010 Location: Aurora, ON, Canada iTrader: (6) Garage List 2008 BMW M5 [9.50] 2006 Z4M Coupe [8.77] 2010 BMW S1000RR [10.00]	You will not set off lights. __________________ E86 ///M Coupe - Imola Red/Imola Red E60 ///M5 - (6 Speed) Silverstone Metallic/Black F06 640iX - Tanzanite Blue/Amaro Brown K66 ///M1000RR - Competition
	Appreciate 0 Quote

09-14-2015, 07:00 PM	#8
dc_wright Captain 249 Rep 758 Posts Drives: 2006 Z43.0si Roadster Join Date: Oct 2014 Location: Orlando, FL iTrader: (0)	I've been running 255/35 x 18 (25.0" diameter) up front, and 275/35 x 18 (25.6" diameter) in the rear. I've done a couple track sessions and to date the only time DSC came on was when I hit some coolant the car ahead of me vented in a tight, medium speed curve, and I suspect DSC would have been triggered there regardless of tire diameter. __________________ Top Down 365
	Appreciate 0 Quote