It is well known that an engine uses more fuel at higher engine speeds due to increased engine friction and lower volumetric efficiencies. By shifting to a higher gear earlier, fuel can be saved. From November, the EU will implement regulation 661/2009 regarding the fitment of gearshift-indicator lights (GIS) in the instrument clusters of all category M1 (passenger) vehicles that are type-approved. This regulation states that all vehicles fitted with manual or auto ‘boxes with a manual override function and which are destined for the European market have to be fitted with GIS to aid in lowering fuel consumption and CO2 emissions. Independent tests to assess the effectiveness of GIS have shown that a substantial saving can be realised by following the shift guidelines. Currently, two implementations of the GIS exist, one connected to engine speed and another, more intelligent system that is linked to fuel-consumption maps in the engine-control unit (ECU).
