=An optimal combustion takes place only if in every load state and at every speed the air-fuel ratio (AFR = air-fuel ratio) has an optimal ratio of 14.8 : 1. Man speaks then also of the LAMBDA – value 1.0.= The stoichiometric air-fuel ratio is 14.7:1, that is Lambda=1, but not 14.8:1 (14.7kg air for 1kg petrol. 14.8 is already lean). =If the air proportion is too high, the engine runs lean and too hot. If it is too low, one speaks of an air-fuel ratio of 14.8 kg petrol. Both conditions always lead to loss of power, uncultivated motor run, overheating or extra consumption!= Maximum power is achieved with Lambda~0.95 (AFR ~ 13.97), i.e. slightly fat mixture, but not with Lambda=1 (with the latter the three-way cat achieves its highest efficiency). If the engine is too fat the engine runs colder because the combustion of hydrocarbons with too little air leads to an increased amount of CO (instead of CO2). t more energy (temperature) free than that to CO, otherwise colder. CO can supply further energy in case of further combustion, is in principle itself still a “fuel”. Otherwise it was m.W. chargeable to push here for a (own) company Advertising. Greetings Uli