English 
how to adjust speedometer for larger tires
Increased wheel size classification:
The wheel hub is enlarged, the diameter and circumference of the tire remain unchanged, and the speed per hour does not change. When the wheel hub is enlarged and the diameter and circumference of the tire are changed to be larger than the original tire specification, the actual speed of the vehicle will be greater than the speed displayed by the instrument at the same speed per hour. When it is smaller than the original tire specification, the actual speed of the vehicle is lower than the speed displayed by the instrument.
Considerations for increasing wheel size:
It is not advisable to change the size of the wheel too wide. The larger the wheel, the thinner the tire will be in order to maintain the flat ratio of the vehicle, and the feeling of the ground will be more obvious. When passing through uneven road sections, the comfort of the passengers will be greatly reduced. It is necessary to always pay attention to the tire wear of the vehicle, because the tire wear will be aggravated after the replacement of the large wheel hub, so frequent inspections are required to avoid traffic accidents. It is necessary to pay attention to the modification of the wheels. Only the wheels of the same size can pass the annual inspection. If the wheels are not of the same size, they will not pass the annual inspection.
If the diameter of the replaced wheel hub is no more than 1 cm from that of the original car, there is no need to adjust the speedometer and odometer of the trip computer. If the difference between the changed wheel hub and the original one is more than 1 cm, the speedometer and odometer of the trip computer need to be adjusted. It should be noted that it is best not to change the hub. If the hub is too wide, the inner diameter will be changed, which is very dangerous. If the wheel diameter is too large, there will be an error between the stopwatch and the actual speed, which will lead to overspeeding "unknowingly" when running at high speeds, and there are also risks such as scratching the wheel arches and fenders.
Get a Quote / Info