You have an abnormality, just ask your partner. And your car has one too, by the way. It is well known that the speed indicated by your car often deviates slightly, but unfortunately you cannot use this as an excuse towards the traffic police. This is why your speedometer often reads more, but never less. Please note: this only applies to cars that have not been modified.
We must also admit that the deviation in modern cars is not too bad. Especially cars of – let’s say – ten years and older sometimes have a somewhat larger deviation. As you might have expected, there are even rules for this. The European Union has a substantial handbook that all cars that are sold new in the EU must comply with.
Why your speedometer often shows more, but never less
According to the official rules for cars delivered new in the EU, the odometer deviation may be a maximum of 10 percent, plus 4 km/h. So if a car actually drives 100 km/h, the counter may indicate a maximum of 114. At 200 km/h in real life, that is a maximum of 224 on the counter. It pays to use a GPS app to see what the difference is with your car.
The same rules also state: ‘The indicated speed must not be lower than the actual speed of the vehicle.’ Car manufacturers therefore prefer to indicate a slightly higher speed than to run into problems with the type approval. This also saves you, because you can never get a speeding fine if you stick to the speed limit according to the speedometer.
This does not apply to cars with other rims
The moment you mount other wheels with a different size, the deviation can change. If you mount larger wheels, you may drive faster than the counter indicates. Especially for people who have a different size for their winter wheels, it is useful to take a look with the GPS when they switch back to the summer gear.