An optimum shift timing indicating device for a vehicle includes: a speed sensor for detecting a rotational speed of an engine or a running speed of the vehicle; a load sensor for detecting an engine load; a data processing device having a data map or maps fewer in number than gear positions of the vehicle...http://www.google.co.uk/patents/US4622637?utm_source=gb-gplus-sharePatent US4622637 - Optimum shift timing indicating device for a vehicle
