Went with 17's - speedo off.

JBushman73

Founding Member

Aug 29, 2001

172

0

0

Roanoke, VA

Oct 7, 2004

#1

• Oct 7, 2004

• #1

My brother just bought an 01.

He put the 17's I took of my GT. What is the best or easiest way to correct the speedo?

Thanks guys!!

 

Lsredy2kstang

Look, I'm special, dammit

Nov 29, 1999

2,543

5

0

Woodstcock, Georgia

Oct 7, 2004

#2

• Oct 7, 2004

• #2

There are no really ways to fix the speedo but then again the margin of difference is so minute that you will not notice it.

Also if you want to see how off it is use the on board instrument cluster diagnosis thingy mybob to see how off it really is.

 

5-SpeedStallion

Founding Member

Mar 28, 2002

230

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0

Tampa, FL

Oct 7, 2004

#3

• Oct 7, 2004

• #3

The overall diameter of his stock 16's with higher profile tires is virtually the same as the overall diameter of the 17's he now has with lower profile tires. Don't worry about it.

BTW, wouldn't the digital speedo be off just as much as the analog? Don't they both measure by how fast the axles rotate?

 

Mustang5L5

That is…until I whipped out my Bissell

Mod Dude

Feb 18, 2001

43,248

17,929

224

Massachusetts

Oct 7, 2004

#4

• Oct 7, 2004

• #4

What size tires are on them??

If they are 245/45/17's don't worry....speedo will be the same

 

R

RdPonyCv

Founding Member

Jan 26, 2002

77

0

6

Illinois

Oct 7, 2004

#5

• Oct 7, 2004

• #5

I thought the digital speedo was programmable. I know with my 95 I need to change gears but don't the 01's have digital?

 

JBushman73

Founding Member

Aug 29, 2001

172

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Roanoke, VA

Oct 7, 2004

#6

• Oct 7, 2004

• #6

The speedo is analog. I put the wheels/tires side by side when installing for him. The 17's looked to be about a half an inch taller.

Sounds like it isn't a big deal. Maybe we'll just say the heck with it then.

Thanks folks!!

 

Mustang5L5

That is…until I whipped out my Bissell

Mod Dude

Feb 18, 2001

43,248

17,929

224

Massachusetts

Oct 8, 2004

#7

• Oct 8, 2004

• #7

JBushman73 said:

The speedo is analog. I put the wheels/tires side by side when installing for him. The 17's looked to be about a half an inch taller.

Sounds like it isn't a big deal. Maybe we'll just say the heck with it then.

Thanks folks!!

Click to expand...

WHat size tires originally come on V6's and what size tires are on the 17" wheels??

I can tell you how much taller and how much off your speedo will be if you give me the sizes

 

R

RdPonyCv

Founding Member

Jan 26, 2002

77

0

6

Illinois

Oct 8, 2004

#8

• Oct 8, 2004

• #8

Well, if it is a 245/45 17, the diameter is 25.68"

Original should have been a 205/65 15 which is 25.49" diameter.

For anyone who wants to know how to figure tire diameters.

eg. 245/45 17

245/25.4, this gives you the width of the tire. (245 is in millimeters, why, who knows)

take that result and multiply by .45 or 45% which is your sidewall height

Multiply sidewall by 2 and add rim size to get overall diameter.

245/25.4 = 9.645 inch wide
9.645*.45 = 4.340 inch tire profile
4.34*2+17 = 25.68 inch diameter

You guys can figure the rest.

 

marvinmycat

Founding Member

Feb 13, 2002

1,179

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0

Buffalo, NY

Oct 9, 2004

#9

• Oct 9, 2004

• #9

Acceptable range for tires on sn95+ Mustangs is from 25.4" to 26.1".

Within that range, any speedo should be fine.

Analog speedo's have two ways of being corrected. One is with a speedo gear reserved mostly for geat swaps, but as you move past 3.73 toward 4.10's, the highest speedo gear won't match the speed correctly. Second way is to pull the gauge pod apart, and match speed with a friend and put the needle back on the speedo post at the correct MPH. Your odometer will always be off though.

Digital can be changed by either a speedo chip purchased from Dallas Mustang, or when you go to reprogram your car's chip.