Mechanics

Odometer

The odometer is a device that informs the user on the miles traveled by a particular vehicle. An odometer is designed in two types, mechanical and electronic. The readout of the mechanical odometer uses 6 rolling disks with numbers 1 through 9. Electronic odometers give you a digital readout of the mileage. Digital odometers are usually part of a larger digital display panel in newer vehicles, odometer displays are usually under the speedometer.

Odometer
Odometer

The odometer has been around since around 27 BC. It was first put to use by Vitruvius, a Roman writer and architect. His odometer was a chariot wheel four feet in diameter turning 400 times for one Roman mile. There was a 400 tooth cogwheel that turned one complete revolution per mile. This cogwheel engaged another wheel that dropped pebbles one by one into a box. The distance traveled would be measured by counting the pebbles at the end of the trip. Odometers have been used by the ancient Chinese, by the mile markers of Alexander the Great and even Benjamin Franklin. Modern inventors like William Clayton who created odometers that used separate gears that control each digit as we know today.

When purchasing a car the odometer informs you on the wear and tear the car has been through. The main problem with mechanical odometers is that the dials can become worn and the gears can strip. Since the odometer is an internal item there is no preventive maintenance needed. The odometer is equipped with a trip meter call a trip odometer that allows the user to check the mileage of any particular distance separate from the main odometer. The trip odometer can be reset by the user.

Odometer Fraud

One of the most common automotive scams involves the odometer. By rolling back the mileage a buyer can be tricked into thinking there are fewer miles on the vehicle than actually are. Here are some tips to let you know when you are dealing with a car that might have the odometer rolled back:

  • Look for fingerprints on the inside of the plastic cover over the gauges
  • Make sure the numbers on the odometer are lined up straight
  • When you test drive the vehicle, see if the odometer sticks
  • Check the maintenance record of the vehicle
  • Look for service stickers that may show actual mileage. These are on the inside of the door or under the hood.
  • Check the car's title to see if there are any corrections on the mileage.
  • Ask the repair facility for warranty records, this can be checked from their computer system.
  • Check the date to see when the title was issued. If the title date is recent then the new title might have been created to hide a mileage change.
  • Look for wear on any place in the car that someone would have contact with. The steering wheel, or arm rests and pedals are good examples of this. Does the wear match the odometer reading?
  • Consult an independent car information website like carfax.com
  • If you are still in question about any vehicle have it inspected by a local garage. A trained technician can give you an evaluation of the car. These tips and tricks will protect you from this type of fraud the next time you go to buy a vehicle.

    If further technical assistance is needed, ask our team of certified car repair technicians.

    Related Car Repair Information

    AUTHOR


    Written by
    Co-Founder and CEO of 2CarPros.com
    35 years in the automotive repair field, ASE Master Technician, Advanced Electrical and Mechanical Theory.


    COMMENTS TO THIS ARTICLE


    Please use our question form if you have a specific question about your car as we are not able to give you a full answer on this page.



    Article first published (Updated 2013-11-21)