The Ford Barn

carnut · 06-27-2010, 08:04 PM

I put 600-16 wheels on my 29 tudor (21inc, tires) the 21s are 96inc. OD the 16s are 89inc.OD what is the diff. in MPH? Many thanks!!

CWPASADENA · 06-27-2010, 09:28 PM

With the 16 in. tires, your road speed will be apx. 7.5% slower with the same engine speed.

For Example,
Assuming your speedometer was correct with the 21 in. Tires.
With the 16 in. tires, when your speedo is reading 45 MPH, your road speed will only be apx. 42 MPH.

You can correct most of this error by replacing the speedo gear (Turtle) on the torque tube with one with one more teeth. Theroretically, your speedo will read a little fast but this is better then reading too slow.

If your speedo read a little fast before, change the gear with one with two more teeth.

I hope I have done my math correctly.

Good Luck and let us know how you came out.

Chris

MAG · 06-27-2010, 09:30 PM

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Just a guess.....MPH will be approximately 7% slower than the speedo reading.

06-27-2010, 08:04 PM	#1
carnut Member Join Date: May 2010 Posts: 35	wheels I put 600-16 wheels on my 29 tudor (21inc, tires) the 21s are 96inc. OD the 16s are 89inc.OD what is the diff. in MPH? Many thanks!!

06-27-2010, 09:28 PM	#2
CWPASADENA Senior Member Join Date: May 2010 Location: PASADENA, CA Posts: 1,931	Re: wheels With the 16 in. tires, your road speed will be apx. 7.5% slower with the same engine speed. For Example, Assuming your speedometer was correct with the 21 in. Tires. With the 16 in. tires, when your speedo is reading 45 MPH, your road speed will only be apx. 42 MPH. You can correct most of this error by replacing the speedo gear (Turtle) on the torque tube with one with one more teeth. Theroretically, your speedo will read a little fast but this is better then reading too slow. If your speedo read a little fast before, change the gear with one with two more teeth. I hope I have done my math correctly. Good Luck and let us know how you came out. Chris

06-27-2010, 09:30 PM	#3
MAG Senior Member Join Date: May 2010 Location: Austin, Texas Posts: 926	Re: wheels Sponsored Links (Register now to hide all advertisements) Just a guess.....MPH will be approximately 7% slower than the speedo reading. __________________ I noticed the harder I work the luckier I get!