Just bought a TomTom on Thanksgiving. So l thought of checking speedometer readings on my G5 versus GPS. Here are my results.
RE Speedometer GPS (mph)
20 mph 18
30 mph 28
40 mph 37
50 mph 46
60 mph 55
70 mph 65
80 mph 75
At lower speeds, the difference between speedometer and acutal speed is only 2 mph (less). It increases to 5 mph (less than actual) at 60 mph and then remains constantly off by 5 mph (less than actual). Just to make sure that my TomTom GPS was good, I tested it against my Toyota Corolla car. The readings were right on.
On a different topic, I tested the battery since I have 4100 miles on my G5 and it is getting cold. Before I started the engine, it read 12.4 volts. After starting, while it was getting charged it jumped slightly to 12.7 volts. So far it looks fine. Looks like the battery will be able to handle heated gloves that I intend to use in the next few days to prevent from freezing my hands.