It seems like the speedometer in my '91 744 is reading fast- When I keep pace w/ traffic on a 35mph road, I'll be reading about 50mph. I just noticed that when I start the car, the spdo reads "0", but when I put it in gear and travel over 10mph, when I come to a stop the needle will only drop down to 7-8mph. If I turn the car off, and restart, the needle will read "0", but the same thing will happen once I'm off and driving. Is this normal for the spdo to not go all the way back down to 0? I would think not, but I'm no engineer...

Forget about the usual tests for speedo accuracy. That needle-not-coming-to-rest-when-stopped part is significant. Your electronic speedo head is going goofy. The common issue with all things electronic in a Volvo (not matter whether ALPS, Bosch, Siemens, or other) is failing solder connections on controller PCBs. In other words, most likely inside the speedo head itself. A bad ground circuit to the dash MAY be able to cause this, but other gauges would be affected too.

If you know how to solder, or know someone that does, the speedo head can be repaired after removing it from the dash cluster. Otherwise, a used speedo from a boneyard or eBay would be your best alternative.

Could be a couple of things : #1 wrong size tires on car #2 wrong speedo in car #3 bad speedo or sender One way to check if your speedo is reading correctly is via highway mileage markers(assuming your state has them). Keep at a constant speed. For the sake of keeping this simple lets say 60mph. Which would be one mile per minute. Take note of time(to be super critical use a stopwatch)it takes you to go from one mile marker to next. Should be exactly one minute. Wish I could offer better/more help but do hope this helps you somewhat.
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' 88 740GLE auto wagon nearly 167,000 and ' 87 240DL auto sedan nearly 125,000

I am using the tire size recommended in my owner's manual (185/65/15), and I'm 99% sure it's the original speedo. We do have mile markers here, they actually put in not just mile markers, but 1/5 mile markers that read "36/0 36/2 36/4 36/6" etc etc. So I will dig up my cool red plastic 80's stopwatch and head for the highway. Thanks for the tip!

I have exactly the same problem and I noticed that this has been met in the past with little to no response. I hope that someone here has an idea on what is going on.