Mileage on a semi truck is the undisputed factor when determining the value of the truck. When people think of low mileage they normally think in terms of cars. Low mileage on a car and a truck are two completely different things. For instance a truck with 200,000 miles is considered very low mileage on a semi truck, a car with that many miles would be worn out more than likely. When verifying the mileage on a semi truck there is more to it than just looking at the odometer. Semi trucks have what is called an ECM. The ECM or Electronic Control Module’s primary function is to control the engine’s performance, fuel efficiency, and emissions; to safeguard the engine from abuse; to troubleshoot mechanical problems; and to monitor the operation of the vehicle. In order to verify mileage on a truck the ecm has to be checked. To check the ECM you have to have a computer that plugs into the truck and downloads the data collected by the ECM. All New semi truck dealerships have this capability and most used truck dealerships have this capability as well. Very rarely do the odometer and the ECM match, but they should be with in a few thousand miles of each other. When selling a truck we use the higher of the two numbers between the odometer and the ECM.
Another way to check the trucks ECM which isn’t as accurate as having it read from a computer is to call the engine manufacturer and ask for the latest date and mileage of any service or warranty claims. The most helpful engine manufacturer that I have dealt with is Caterpillar. They have a national hotline with many helpful service agents who are always willing to assist in providing the information they have on the trucks ECM.
The following video is a good description of how an ECM is used. Remember if you or someone you know is looking to sell your semi truck please fill out the sell my semi truck form on our website. Someone will contact you to discuss your truck with you.