It might just be parallax. You might not be viewing the analog gauge square on, since it sits off to the right a bit.

 

My 2010 has always appears this way as well. Also agreed it's most likely the viewing angle. On the plus side, when I set cruise to what "looks" like 10 over, I know I have a small cushion that says I'm not quite 10 over. haha

 

It's definitely not the viewing angle. At higher speeds (around 130 km/h), my speedometer is showing 132-134 km/h, while the HUD and the ACC are showing 130 km/h.

I also had a situation this week where the ACC was showing as set at 130 km/h, but the HUD was showing 129 km/h for a significant period of time on a flat stretch of highway.

 

The speedometer is an analogue device and I'd be very surprised if it matched the digital display on a consistent basis - that and manufacturers tend to set the speedometer to read a bit higher than the actual speed. Why?... because if it read lower than actual customers would be very upset about getting speeding tickets.

FWIW my speedometer reads about 2 mph higher than the HUD at 75 - not a big deal and doesn't bother me.

 

I'm glad we sorted that out.

 

I think I will try this on the interstate soon. In light traffic set the ACC to 60 mph by toggling up or down the +- toggle on the steering wheel and after steady state, look at the heads up display and analog speedometer reading. Have my iPhone in my lap on the stop watch app. When I pass a mile marker, start the stop watch and stop it at the next mile marker. Ideally the stop watch would read 1 minute exactly. While driving, eyeball the heads up display and the analog speedometer. This test would reveal the ACC speed setting accuracy, the heads up display reading, and the analog speedometer reading. You could also try it at other faster speeds and calculate the time it would take to go a mile at that speed for the stop watch benchmark.

 

You could also use Waze on your phone and see if the MPH is different on that app than it is in the car. Or with an old-fashioned Garmin. The speedmeter has always been 3 MPH slower than any of them.