speeodeter error, way low!!!

[odie13]

I was driving to work in my new/old 1981 diesel rabbit. I checked the speedometer with GPS.

60 mph indicated.....68 mph GPS

I guess the little rabbit is a lot faster than indicated

An extra 8 mph or 13%

is this normal?

The odometer is not working, goes to .1 mile and stops. Is this the cause or are my tires just way too big?

Front tires are 175/80-13

Rear tires are 180/75-13

that's just how I got the car.

[odie13]

I think I have part of the answer...

I found that 155/80-13 is the base tire size for the car. Not sure if that is for diesel or gas rabbits. I also found a 175/70-13 listed as optional size. The car is a 4 door diesel LS Deluxe.

but even then, 175/80-13 is only about 3% bigger than the small tire.

Still alot of error

[lugnut01]

My 82 Rabbit has the same problem and about exactly off the same amount as yours.
Nobody passes me when I drive 65.

I get my doors blown off driving 65 in my other cars.

I also have a 1996 Jetta that is off a little less, but in the opposite direction.

-Joe W

[zagrot]

i was thinking about this post while i was driving earlier tonight, mostly because i thought i spotted a highway patrolman (but if the "this is your speed" radar signs are accurate, my speedo is dead on so i would have been ticketed anyway). since most early vw's are of dubious origin, and most certianly not virgins, it is possible that an earlier owner has been poking around in the speedometer, probably due to the odometer problem (there is a plastic gear in there that is prone to breakage; maybe sure to break is more accurate). most people's intuition is to reassemble the speedo with the needle pointing at the stop, but if you look at the graduations it is clear that the scale starts at 10mph. the correct way to assemble the speed is with the needle pointing at a barely noticable mark on the very edge of the of the gauge face (so i seem to remember). this mark is 0mph, after the needle is set you'd just lift it enough to clear the peg at 10mph and pass it over into the useful part of the scale. removing the needle is not for the faint of heart as they are prone to breakage during the process, but the gist of the thing is to use two small prying insturments and two small blocks, one on each side of the needle, and pry it straight off of the post. don't reseat it with a vengance, just incase you find yourself doing the job later.