This is different in Germany but we learn about tolerance in driving school. Your speedometer can be wrong by about 10% and speed guns can also have errors. A good system accounts for unintentional speeding.
Displaying a speed slightly higher than actual speed is common and an acceptable margin of safety, such that if you are driving at the speed that the speedometer shows, you are more or less guaranteed to not exceed the speed limit.
The amount you are allowed to drive over the speed limit is in fact 0mph (0 km/h for us Europeans).
Tolerance of violations of this is a sign of a deeply broken society
This is different in Germany but we learn about tolerance in driving school. Your speedometer can be wrong by about 10% and speed guns can also have errors. A good system accounts for unintentional speeding.
Speedometers are not allowed to display a lower speed than the vehicle is running at all under EU regulation - see https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CELEX%3A42004X0331(01)&qid=1752829119241 § 5.3
Displaying a speed slightly higher than actual speed is common and an acceptable margin of safety, such that if you are driving at the speed that the speedometer shows, you are more or less guaranteed to not exceed the speed limit.
In the UK you’re allowed 10% (and I think +2mph) due to car speedo’s not being 100% accurate.
It’s actually not law, just custom. Most/all speedometers over estimate for this reason.
The motorway cameras, near Birmingham have been known to issue tickets for doing 71mph.