There is a formula in our tire modification industry, which adds ten MINUS five and remains unchanged, and adds ten MINUS ten plus one.
In this case, the first half of the formula should be applied without changing the tire size, adding ten words and subtracting five words. For example, the tire size of the original car is 195/60/ 16. In order to improve the grip of the vehicle and make the whole tire look fuller, it can be changed to 205/55/ 16 without changing the hub. For another example, 175/70/ 14 can be changed to 185/65/ 14, which is basically the most reasonable. The error between the actual tire speed and the speed displayed by the on-board instrument is less than 3 km/h, but this formula is not omnipotent. Sometimes you will find that there is no such mode after the conversion. For example, 215/5516 is converted into 225/50/ 16, so this formula can't be completely copied sometimes.
In the case of changing the tire size, the second half of the formula is applied, plus ten MINUS ten plus one, but the application scope of this formula is relatively small. For example, Regal's original car 225/55/ 17 can be changed to 235/45/ 18, which is a very reasonable change, but there are also many things that cannot be converted, such as 245/45/.
If the above formula can't be used, if the formula can't be used, you can use Baidu tire size conversion tool to input the tire size of your original car and the size you want to change. After conversion, as long as the error between the actual speed and the speed of the code table is plus or minus 3km/h, it is also necessary to consider whether the tire will rub against the fender after widening and heightening. This must be noted.
Therefore, in our tire modification industry, the formula of ten MINUS five remains unchanged, and ten MINUS ten plus one is only convenient for our usual calculation. If the formula cannot be applied, we need to use professional software. Remember to pay attention to the speed error of plus or minus 3km/h when refitting, and be sure to pay attention to whether the fender liner will be scratched when the direction is killed.
The above is my personal experience. If you like it, please leave a message.