If the use of trip computer, in large quantity is more or less new for the normal car, and chiefly for consumption purposes , since a very long time the rallye car men use mechanical devices which make approximatively the job of trip computer for times and speed. The purpose of this paper is a short presentation of these mechanical devices to indicate how they are used during rallye operations, what they bring to the driver or more exactly to the copilote and to introduce what a trip computer equipped with a microprocessor may offer.
Finally a description of the electronic rallye trip computer designed by our firm, but in accordance with the wishes of the more famous rallye pilot will be undertaken.