My new Jeep GC has a big Garmin screen and it displays speed. That and the speedometer are dead nuts the same. It's like the speedo is taking its reading from the GPS.
Of course, like everyone, my 986S is +3 at most speeds.
After reading this thread earlier today I installed GPS Essentials on my phone and compared the GPS reading with both cars. The Boxster is consistently 3mph over the GPS reading; while my Impreza is in the range of 1-2 mph over the GPS. So I guess I can set the cruise slightly higher when driving at police officer friendly speeds.
Hybrid Mode
