MKIV speedometer calibration

Gotrek

Veteran Member
Joined
Jan 29, 2015
Location
Mont-Pubis, Canuckistan
TDI
1
I searched and found many posts for later models but is it possible to recalibrate the speedometer in a MKIV Jetta?

My speedo and actual speed are way off.

If my speedometer shows 118kph I'm actually doing 105 kph or so.

It took me a long time to figure out why people kept passing me. I thought everyone up and decided to speed the day I bought the car.

57kph =50kph

Or does someone have a calculator that could help me figure out how much of a taller tire I'd need to offset the reading? I run stock 195/65r15's right now.
 

Lightflyer1

Top Post Dawg
Joined
Sep 13, 2005
Location
Round Rock, Texas
TDI
2015 Beetle tdi dsg
Just remember it throws the odometer off if you correct the speedo. Some resorted to opening the speedo and resetting the needle slightly slower to avoid this. There is no other way to correct the speedo without affecting the odo too as they both use the same input signal.
 
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mjydrafter

Veteran Member
Joined
Jul 12, 2015
Location
dsm, ia
TDI
2004 Jetta Wagon
Pretty easy to check, pop on the interstate and check it against the mile markers. :D
 

RIP TDI

Top Post Dawg
Joined
Feb 16, 2000
Location
Santa Barbara, CA
TDI
'15 GSW SE 6MT, '01 Golf 5MT, '97 Passat sedan, '96 Passat variant
Just remember it throws the odometer off if you correct the speedo. Some resorted to opening the speedo and resetting the needle slightly slower to avoid this. There is no other way to correct the speedo without affecting the odo too as they both use the same input signal.
Actually, the two can be corrected independently, but it requires Vag Tacho or its ilk and some programming knowledge.
 

joep1234

Veteran Member
Joined
Jan 2, 2014
Location
NC
TDI
former '04 Beetle TDI, now 2x '15 Audi Q5 TDI's, 2007 Dodge Ram 4x4 6.7
I went with 205/60/16 tires and at 60 mph I am showing just 2 mph slow. Before I was slow by 6 mph. My son read somewhere that VW set these cars off so the cars would show 0-60 times faster than they were. The tires give me about 1' extra clearance so I don't scrub the bottom of my car on the speed bumps.
 

mjydrafter

Veteran Member
Joined
Jul 12, 2015
Location
dsm, ia
TDI
2004 Jetta Wagon
My TDI is pretty close to exact, just slightly under indicated.

My wife's Passat is off by a bit like 5-7 mph low at 70-75. I asked her if she wanted to me to fix it, but she said that it was fine... she likes to speed, so I left it. :p
 
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