How well does the factory GPS work?
From peter@smallworld-us.com: I thought I’d give a bit of feedback on the navigation system, as there hasn’t been much on this forum. Overall I am very impressed with it. Some of the previous discussion on this forum comparing the Mercedes system (made by Siemens) with PC based systems misses the crucial point that GPS alone is not very accurate – there is a deliberate error introduced into the signal which can make it inaccurate by up to 100 meters or so. To get a really accurate location you need to combine GPS with distance and direction sensors in the car, together with road database information. See the link below for more discussion on this topic. This fact makes the dedicated in car systems much more accurate than a PC based system which just uses GPS. I have been very impressed with the locational accuracy of the system – in most cases it locates a junction to within a few yards. The database accuracy has been pretty good – I have come across a few cases where it did not have t
