My 97 DI speed reading is off about 7or 8%. (It reads 60 when the GPS reads 55). Tires are 235/70/16. Is not a big issue, but is there any way to adjust or calibrate the speedometer?

 

I haven't heard of any way to adjust the speedometer. Maybe a mechanic can go in to the computer and adjust it. D1 speedometers being off is very common. My speedometer read about 10% faster than my GPS and I am running the stock size tires just like you.

 

Dont worry about it.
Mine does the same thing, not worth trying to fix, just adjust your speed accordingly.
Set my cruise at 70 so I can actually do 65.

 

Yeah, that is what I thought. It doesn't bother me a bit, except when my wife is driving, she sets the CC at 65 and everybody passes us. She won't hear about the reading being wrong. If you are married, you probably understand me.

 

Married with 3 kids.
When my son took his drivers test he drove the truck, he had to go by the speedo because he couldnt tell the tester that the speedo was wrong.
He said it took forever because you must drive the speed limit and when the speedo is 5 over...
My wife understands, the Blizzaks are to big for her Volvo so her speedo is off by 10mph in the winter time.

And to solve your problem dont let her drive.

 

Somethings about Rovers it's better to just accept or you'll go crazy trying to fix it. The speedometer is going to be wrong and the valve covers are going to leak. It's enough to drive you crazy but it's just how it is.

 

The speedometer will be off on most cars and trucks but the odometer will be on the money.
I have found this on most of the cars and truck I have driven the that 10 years.

 

Both your speedo and odometer will be off and there is nothing you can do about it.

 

Humm, I had not thought about that one, My car actually has 10% less miles than I thought. That is refreshing

 

I've found that my odometer is right on according to the trip meter on my GPS.