This is topic fox speedometer's actual mileage? in forum Tech Talk at Northern California Ford Owners  .


To visit this topic, use this URL:
https://californiafords.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=6;t=006989

---

Posted by gercolla1 (Member # 3068) on :
 
In the mid 90's I had 355's installed in place of the factory 273's. Just before the swap the car had 40K. I never calibrated anything so the speedo always read faster. Today the odometer "reads" 170K. I can barely guess the actual mileage. Can I ever calculate this, at least within several thousand miles?
 

---

Posted by 66 AC COBRA (Member # 904) on :
 
u have 140k original miles
 

---

Posted by 66 AC COBRA (Member # 904) on :
 
when ur doing 70mph, ur speedo is saying that ur doin 90mph
 

---

Posted by DropTopFox (Member # 1689) on :
 

quote:

---

Originally posted by 66 AC COBRA:
u have 140k original miles

---

what he said
 

---

Posted by gercolla1 (Member # 3068) on :
 
not bad
 

---

Posted by AL STOCK (Member # 1852) on :
 
Yeah i have 3.73s and is been installed for over 8 months now....When i had it installed i had about 129K miles now it reads 153K..Lotta driving to Sacramento also so somewhere around 138K acutal mileage -

How much do calib. cost?
 

---

Posted by graylx (Member # 3919) on :
 
A way to calculate.

170,000 miles on odometer currently
- 40,000 miles before swap

= 130,000 "miles" since swap

130,000 x 2.73 (original gear ratio) / (divided by) 3.55 ( your current gear ratio)will give you accurate mileage. The speedo gear (as well as odometer) in your tranny is calibrated for 2.73s but some math will allow you to determine relatively accurate mileage.

so...

130,000 x 2.73 = 354,900

354,900 / 3.55 = 99,972

99,972 miles since gear swap

99,972 miles + 40,000 original miles =

approximately 140k miles.

I wish I had a life.
 

---

Posted by DropTopFox (Member # 1689) on :
 

quote:

---

Originally posted by AL STOCK:
Yeah i have 3.73s and is been installed for over 8 months now....When i had it installed i had about 129K miles now it reads 153K..Lotta driving to Sacramento also so somewhere around 138K acutal mileage -

How much do calib. cost?

---

It's a $25 little piece man. pick it up from brother's or steeda. It's just a tine little gear. If you don't know where it is I'msure you can run it over to Rob's or his cousin John's really quick and they could show you
 

---