Speedometer calibration

Did you get this figured out?

 

I got a faulty unit. The replacement unit should be later this week.

 

any updates? Did you update gearing? I have been reading that you only want to update tires size and not gearing...

 

This is a 3+ year old thread that has come back twice.

Short answer. It just isn't worth the trouble to worry about. Even with factory tire sizes your speedometer and odometer will vary 5% or more between when your tires new and when you have 40,000 miles on them. Tires get smaller as they wear down and there is no way for your speedometer to be accurate 100% of the time.

If you go up in tire size, then go to the trouble to re-calibrate the speedometer, it will be wrong within a year or so. If you go up one size the tires you buy today will be the same size as the old ones were when they were new in a few months.

You have to go up in tire size pretty significantly for your speedometer to be off by even 5 mph at 70. It ain't rocket science to know that if the speed limit is 70, then don't go over 65. And there are virtually no places where you'd get stopped for doing 75 in a 70 mph zone. At slower speeds under 50 mph you're talking about being off by 1-2 mph. That is an insignificant number.

 

Didn’t work for my early 2nd gen. 2.5 and 3rd gen owners have had better luck.

 

I’m running 35’s with 5.29’s.

edit: Also... does this really help with shifting points as well?

 

Installed yesterday to accommodate 275/70 R17 (32.16") and 4.30 gears.

Before: GPS speed of 55 = 61 indicated
After: GPS speed of 55 = 54 indicated.​

I'll take that!

However, I now have a "check engine" light to chase down. I've read removing the zip ties has worked for some. I'll try that first.

Butt

 

Update:
My "check engine" light was coincidental. Code cleared and now all's peachy and working great.
Butt