Hi, can someone tell me how the ECU calculates the engine load (this value isn't measured directly). All I found about engine load is that this is the value that tells us how much load an engine is overcoming in the dependence of how much load it could overcome at the momentarly circumstances. the other thing that I woul like to know is how the ECU determine air to fuel ratio. All I konw is that it uses MAF and O2 readings. But can we calculate how much fuel (g/s) was burned in a cylinder by reading these values (MAF and O2)? If we know that mass flow (g/s) and fuel heat energy (39MJ/kg for gasoline I think), we could calculate how much power engine is producing by subtract the exhaust heat flow from release heat energy in a cylinder. We can easily calculate exhaust heat flow, by knowing air and fuel flow and temperature difference betwen intake and exhaust gases.