Engine number
From Wikipedia, the free encyclopedia
Engine number may refer to an identification number marked on the engine of a vehicle or, in the case of locomotives, to the road number of the locomotive. The engine number is separate from the Vehicle Identification Number (VIN).

Automobiles
Trains
The term is also used in train terminology.[4] In this instance, it refers to the road number assigned to motive power by the operator, as opposed to a constructor's or builder's number (equivalent to a vehicle VIN number).