A mileometer is the instrument in a car that shows how many miles the car has travelled in its whole life, not how fast it is going right now. Drivers look at it to judge how much work a car has done, when to service it, or whether a used car has a long history. This spelling is British (you will also see milometer). In American English the usual word is odometer, and many textbooks use that. Though actually, most cars in Taiwan count kilometres, so the English name is a little behind the dashboard — people still call the same clock a mileometer in British English, even when the number is in km. It is not the speedometer: that one tells you your speed at this moment.

里程表、里程計（英式；美式多說 odometer）。台灣車上顯示的是公里數，但仍叫里程表，不是速度表。