Why is the TQC speedo an issue? Do the 81-84 US-spec Ur-Qs have 85 MPH
units? What do the Canada and Euro-spec models use? You might be able to
replace the stock unit with a 85-87 4000Q speedo, I think they are marked
to 120 MPH.....
I can't speak for all years but my "82 and all the "83's I've seen
have had that nasty 85 mph speedo. My 84 coupe has a 120, but I was
holding out for the big 160 model.
My [early] '83 has the wildly-optimistic 150mph unit. The owner's manual
however does indeed illustrate the 85mph "US" speedo, with a 240kph "Ca-