Messed up tires sizes.HELP!! -

Koselowiec · 10-20-2008, 10:15 PM

So I orderd my new wheels and tires from tirerack, and put them on. Being the idiot that I am, i ordered 255 45 17 tires. What I needed was 255 40 17 tires. I didn't notice this until today, and the tires have maybe 5 miles on them.

How badly is this going to mess with my speedo?

I don't get any rubbing, but I know my car is not showing actual speed.

Does anyone have any clever thoughts on maybe trading these tires in for new ones that are the proper size?

HELP!!!

**Shuasha** · 10-20-2008, 10:36 PM

Vag-com doesn't have a way to set a correction factor? BMW's have this through the dash display.

leftygibsonplyr · 10-21-2008, 10:09 AM

ya idk if vagcom has a correction utility for that, but i would check and find out. Ask jay, he would know for sure. I doubt that the size you have now vs the ones you had before will make much if any difference in the speedo. keep in mind tires are not made equal. (brand wise) a 255/40 from one company might be comparable to a 255/45 from another company...maybe drive past one of those street signs that tells you how fast you are going and compare it to what speedo says your going. that might give a little bit of an idea. I know mine is about approx1-3mph when i go past those things with the stock tire size...

ZoHeB318 · 10-21-2008, 10:24 AM

Call TireRack?

**Timmahhh** · 10-21-2008, 10:25 AM

according to Tire Size Calculator - tire & wheel plus sizing , here are the differences...

Stock Tire - 255/40R17 >Search Tires

Tire 1 - 255/45R17 >Search Tires

Section Width:

10.03 in

255 mm

Section Width:

10.03 in

255 mm

Rim Diameter:

17 in

431.8 mm

Rim Diameter:

17 in

431.8 mm

Rim Width Range:

8.5 - 10 in

Rim Width Range:

8 - 9.5 in

Overall Diameter:

25.03 in

635.76 mm

Overall Diameter:

26.03 in

661.16 mm

Sidewall Height:

4.01 in

101.85 mm

Sidewall Height:

4.51 in

114.55 mm

Radius:

12.51 in

317.75 mm

Radius:

13.01 in

330.45 mm

Circumference:

78.63 in

1997.2 mm

Circumference:

81.77 in

2076.9 mm

Revs per Mile:

831.0

Revs per Mile:

799.0

Actual Speed:

60 mph

100 km/h

Speedometer1:

57.6 mph

96.1 km/h

Speedometer Difference: -

Speedometer Difference: 4.005% too slow

Diameter Difference: -

Diameter Difference: 3.85%

uiuc240 · 10-21-2008, 10:32 AM

a 4% difference means that if your speedo is showing 80, you're actually going 83.2. However, this doesn't really matter much because most speedos are set a little conservative. My guess is that now you'll be just about right. I wouldn't worry about it at all. I've had oversize tires on almost all my cars with no issue.

for instance, right now I have 205/50 instead of the factory 195/55...

Eric

Koselowiec · 10-21-2008, 11:05 AM

thanks guys. i started freaking out and was ready to order new tires..... I think i can live with 3mph or so.

**Jay::01-S4** · 10-21-2008, 02:41 PM

Yea, the difference should not be much.

FYI - Just for shits and giggles I tried finding the documentation for your car and can't come up with anything that would let me adjust it via VAGCOM.

**Timmahhh** · 10-21-2008, 03:04 PM

Quote:

Originally Posted by Jay::01-S4

Yea, the difference should not be much.

FYI - Just for shits and giggles I tried finding the documentation for your car and can't come up with anything that would let me adjust it via VAGCOM.

The real question is whether or not you were shitting and giggling while looking that up.

**Jay::01-S4** · 10-21-2008, 03:37 PM

Quote:

Originally Posted by Timmahhh

The real question is whether or not you were shitting and giggling while looking that up.

but of course

Koselowiec · 10-24-2008, 02:31 PM

Quote:

Originally Posted by Jay::01-S4

but of course

because its a urS6, can the VAG-Com even be used on it? (total noob question)

I have the service reset tool, and it doesn't have a standard OBD II connector, it uses two black and white pins under the hood, in the relay box. Is there another OBDII port on it?

uiuc240 · 10-24-2008, 06:29 PM

1995 = non-OBDII. OBDII started in 1996, I believe. So, no...no VAG-Com.

Robert@Home · 10-25-2008, 02:43 PM

Quote:

Originally Posted by Koselowiec

because its a urS6, can the VAG-Com even be used on it? (total noob question)

I have the service reset tool, and it doesn't have a standard OBD II connector, it uses two black and white pins under the hood, in the relay box. Is there another OBDII port on it?

http://www.ross-tech.com/Merchant2/m...ry_Code=VAGCOM

I believe ^this^ is what you need.

10-20-2008, 10:15 PM	#1 (permalink)
Koselowiec Audi/VW Service Guy Join Date: Dec 2006 Location: Downers Grove/Indianapolis Posts: 1,055 Car: 1996 BMW 328is	Messed up tires sizes.HELP!! So I orderd my new wheels and tires from tirerack, and put them on. Being the idiot that I am, i ordered 255 45 17 tires. What I needed was 255 40 17 tires. I didn't notice this until today, and the tires have maybe 5 miles on them. How badly is this going to mess with my speedo? I don't get any rubbing, but I know my car is not showing actual speed. Does anyone have any clever thoughts on maybe trading these tires in for new ones that are the proper size? HELP!!! __________________ '96 BMW 328is...Turbo Track Rat Project

10-20-2008, 10:36 PM	#2 (permalink)
Shuasha Burn, Baby, Burn Join Date: Aug 2003 Location: Oak Park, IL Posts: 9,222 Car: Estoril 97 M3/4, Black 93 532iT, K1200RS Images: 2	Vag-com doesn't have a way to set a correction factor? BMW's have this through the dash display. __________________ StreuBocharged 97 M3/4 - Top Mount Turbo Kit, Built/Stroked M50 Non-Vanos, GT-35R, 3" Turbo Back Exhaust, HR/Bilstein Combo, UUC SSK/Sways/LTW Flywheel, AA DSB 93 525iT - S52, manual swap, custom aftercooled intake manifold by JT, GT35R, NickG tune

10-21-2008, 10:09 AM	#3 (permalink)
leftygibsonplyr Learner's permit Join Date: Jul 2007 Location: Plainfield, IL Posts: 2,423 Car: 2003 20th Anniversary GTI IY #1467	ya idk if vagcom has a correction utility for that, but i would check and find out. Ask jay, he would know for sure. I doubt that the size you have now vs the ones you had before will make much if any difference in the speedo. keep in mind tires are not made equal. (brand wise) a 255/40 from one company might be comparable to a 255/45 from another company...maybe drive past one of those street signs that tells you how fast you are going and compare it to what speedo says your going. that might give a little bit of an idea. I know mine is about approx1-3mph when i go past those things with the stock tire size... __________________ - Jon

10-21-2008, 10:24 AM	#4 (permalink)
ZoHeB318 non-emo x-dressing brick Join Date: Jan 2006 Location: Palatine Posts: 15,714 Car: Current: 1999 BMW M3 - Alpine White with AA TS Past: 1998 BMW M3 - Faded Estoril w/ M-Technic int Images: 4	Call TireRack? __________________ 1999 Alpine White/Dove - Stock RIP 1998 Estoril M3 - the one and only faded paint cone pooper

10-21-2008, 10:32 AM	#6 (permalink)
uiuc240 WTB BMW ... need $$ Join Date: Sep 2004 Location: Wheaton, IL, USA Posts: 1,111 Car: 2002 Mazda Protege5 1994 BMW 325is (sold) 1999 Honda CR-V 1989 240sx w/SR20DET (sold) 1990 Acura Integra LS (totaled) 1987 Volkswagen Jetta GL (good riddance!)	a 4% difference means that if your speedo is showing 80, you're actually going 83.2. However, this doesn't really matter much because most speedos are set a little conservative. My guess is that now you'll be just about right. I wouldn't worry about it at all. I've had oversize tires on almost all my cars with no issue. for instance, right now I have 205/50 instead of the factory 195/55... Eric __________________ 2002 Mazda Protege5 (my daily...replaced 1994 325is) 1999 Honda CR-V (her daily)

10-21-2008, 11:05 AM	#7 (permalink)
Koselowiec Audi/VW Service Guy Join Date: Dec 2006 Location: Downers Grove/Indianapolis Posts: 1,055 Car: 1996 BMW 328is	thanks guys. i started freaking out and was ready to order new tires..... I think i can live with 3mph or so. __________________ '96 BMW 328is...Turbo Track Rat Project

10-21-2008, 02:41 PM	#8 (permalink)
Jay::01-S4 SLW Motorsports Join Date: Mar 2005 Location: Elgin, IL Posts: 6,335 Car: 2001 Audi S4 1978 Camaro Z-28 1997 BMW M3/4/5 HeatWare Account: 63982 Images: 23	Yea, the difference should not be much. FYI - Just for shits and giggles I tried finding the documentation for your car and can't come up with anything that would let me adjust it via VAGCOM. __________________ 2001 Audi S4 - kind of stock 1997 BMW M3 - ETK whore 1978 Camaro Z-28 - slightly modded Speed has never killed anyone, suddenly becoming stationary... That's what gets you. -Jeremy Clarkson

10-24-2008, 06:29 PM	#12 (permalink)
uiuc240 WTB BMW ... need $$ Join Date: Sep 2004 Location: Wheaton, IL, USA Posts: 1,111 Car: 2002 Mazda Protege5 1994 BMW 325is (sold) 1999 Honda CR-V 1989 240sx w/SR20DET (sold) 1990 Acura Integra LS (totaled) 1987 Volkswagen Jetta GL (good riddance!)	1995 = non-OBDII. OBDII started in 1996, I believe. So, no...no VAG-Com. __________________ 2002 Mazda Protege5 (my daily...replaced 1994 325is) 1999 Honda CR-V (her daily)

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
new tires needed for BMW 330Ci	thatsonlyme	Wheels, Tires, and Suspension Systems	1	06-19-2008 07:50 AM
James Bond tech for the road: Q Tires develops retractable-stud snow tire	eurospek	General Car Discussion	2	04-01-2008 10:39 PM
You can now buy the same quality McLaren F1 tires for your bimma!	JC_E36	Wheels, Tires, and Suspension Systems	0	10-20-2004 01:14 PM
WTB: E36 5-Speed	RZA36	Car and Parts Classifieds	1	01-11-2004 04:59 PM
staggered wheels?	Bim-dub	Wheels, Tires, and Suspension Systems	24	08-24-2003 04:16 PM