Need to adjust the speedometer when change wheel sizes?

cruvon · 04-08-2011, 03:09 AM

Hi, was speaking to someone and he reckons my car would be showing wrong speedo readings since I changed my wheels. I didn't think so since the outer diameter of the wheels would still be unchanged irrespective of the alloy wheel size? Or does the outer diameter change with bigger wheels thus causing it to show a lower speed than it really is at with bigger wheels?

335i-boy · 04-08-2011, 03:38 AM

Hi cruvon

Wheels are looking great my man. Style 230's look great on E90's. One of the best wheels ever!!

To calculate any difference in rolling diameter, just go to the e90 Post "Wheel and Tyres Forum". There is a handy calculator for this and other useful info on there.

Here is the link: http://www.e90post.com/forums/forumdisplay.php?f=12

cruvon · 04-08-2011, 03:43 AM

Quote:

Originally Posted by 335i-boy

Hi cruvon

Wheels are looking great my man. Style 230's look great on E90's. One of the best wheels ever!!

To calculate any difference in rolling diameter, just go to the e90 Post "Wheel and Tyres Forum". There is a handy calculator for this and other useful info on there.

Here is the link: http://www.e90post.com/forums/forumdisplay.php?f=12

Thanks 335i-boy

, yupz, really impressed with them.
Will check that link out.

sbce90 · 04-08-2011, 04:17 AM

you are 100% fine. Tyre sizes have been suitable adjusted and rolling diameter should be close enough. If you went to like 24" chromies then you would be in trouble

NBTBRV8 · 04-08-2011, 03:51 PM

http://cat.cc/tiresize.htm

04-08-2011, 03:09 AM	#1
cruvon Lieutenant Colonel 83 Rep 1,543 Posts Drives: E90 Join Date: Feb 2010 Location: Sydney, Australia iTrader: (1)	Need to adjust the speedometer when change wheel sizes? Hi, was speaking to someone and he reckons my car would be showing wrong speedo readings since I changed my wheels. I didn't think so since the outer diameter of the wheels would still be unchanged irrespective of the alloy wheel size? Or does the outer diameter change with bigger wheels thus causing it to show a lower speed than it really is at with bigger wheels? __________________ Tiag E90 \| JBSPEED Spli t t ers \| JBSPEED ACS style Roof Spoiler \| JBSPEED M3 style Trunk spoiler \| Euro plates \| K&N Intake \| BMW OEM Performance Exhaust \| Debadged \| OEM Chromeline trim \|230 OEM rims \| 19" Michelin Pilot Sport PS2 Non runflats \| OEM Burr Walnut Gear knob \| OEM Blacklines \| OEM Spacesaver \|
	Appreciate 0 Tweet Quote

04-08-2011, 03:38 AM	#2
335i-boy Lieutenant 15 Rep 457 Posts Drives: E92 335i M-Sport Join Date: Jun 2010 Location: Australia iTrader: (0)	Hi cruvon Wheels are looking great my man. Style 230's look great on E90's. One of the best wheels ever!! To calculate any difference in rolling diameter, just go to the e90 Post "Wheel and Tyres Forum". There is a handy calculator for this and other useful info on there. Here is the link: http://www.e90post.com/forums/forumdisplay.php?f=12 __________________ 2008 E92 335i M-Sport \| Sapphire Black \| Sunroof \| Creme Beige \| Poplar Grey \| Logic 7 \| 6AT \| 19" AG M359's \| Michelin PS4S \| LUX V3 \| MHD V5 E40 \| Steve AZ Walbro inline \| Vishnu DCI \| BMS CP \| AR Design Catless DP's \| Forge DV's \| Helix IC \| (Stock Cat. back) \|
	Appreciate 0 Quote

04-08-2011, 04:17 AM	#4
sbce90 Me Boosta 249 Rep 5,721 Posts Drives: 320i / MB C63 / VW up! Join Date: Jan 2010 Location: Sydney, Australia iTrader: (3)	you are 100% fine. Tyre sizes have been suitable adjusted and rolling diameter should be close enough. If you went to like 24" chromies then you would be in trouble
	Appreciate 0 Quote

04-08-2011, 03:51 PM	#5
NBTBRV8 Captain 137 Rep 859 Posts Drives: LCi E60 530i Join Date: Mar 2010 Location: Australia iTrader: (0)	http://cat.cc/tiresize.htm
	Appreciate 0 Quote