# Slight difference between GPS CAN mileage and physical odometer ## Question Why is there a slight difference between the GPS CAN mileage value and the physical odometer?\*\* ## Answer A common reason is that modern vehicles store and report mileage from multiple control modules (such as the engine control module, body control module, or instrument cluster), which are not always perfectly synchronized in real time. The dashboard odometer typically displays a rounded value, while CAN data may provide more precise readings, including decimals. Additionally, CAN signals are transmitted at intervals, meaning the reported value may reflect a slightly earlier measurement. As a result, small discrepancies—like a difference of around 17 km over 185,000 km—are normal and fall well within expected tolerance. This doesn't indicate any issue with the vehicle or the data, but rather standard behavior in how vehicle systems report mileage. ## Links * [Can bus GPS Tracker](https://www.navixy.com/blog/can-bus-gps-trackers/) --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://navixy.com/docs/qna/device-related-questions/slight-difference-between-gps-can-mileage-and-physical-odometer.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.