• Go to "Configuration" / "General information"
• If you want to use MILES option 24 has to be not checked
• If you want to use KILOMETRES option 24 has to be checked
• Save and Exit.

• Go to POS and click on the spy glass next to the "Customer" field
• Find the customer
• Choose the "Vehicle Maintenance" tab
• Double-click on the vehicle to access the "Vehicle file"
• Choose the mileage
• Save and Exit.

NOTE: If those changes do not appear immediately you can close and restart GEM-CAR. The changes will affect Work Orders, Estimates, Invoices and Service Reminder Letters.