Load

Engine load

Also known as relative cylinder charge. It represents the percentage of air (compared to standard density) in each of the cylinders. 100% load means each cylinder has the mass of air as an equivalent volume at standard density. Ingested air mass is calculated from MAF value (mass/time) divided by RPM (1/time), divided by two to yield a mass. Standard mass is calculated by engine displacement (volume) times standard density (mass/volume). The ratio of the two masses is load. It is used in real time to determine all other values including boost, timing, and fueling. In normally aspirated motors, load will rarely exceed 100%, but in forced induction motors, load exceeding 100% is expected.

$Load={\frac {mass_{ingested}}{mass_{standard}}}$

$mass_{ingested}[g]={\frac {MAF[g/sec]\times 60[sec/min]}{RPM[1/min]\times {\frac {1}{2}}}}$

$mass_{standard}[g]=displacement[cc]\times 0.00122521[g/cc]$

ECUx definitions

Actual ME7 FR definitions in parenthesis.

EngineLoadSpecified (rlmx_w)

The maximum target load, depends only on RPM. Misnomer, should really be something like "EngineMaxLoad"

EngineLoadCorrectedSpecified (rlmax_w)

Adjusted maximum target load based upon rlmx_w corrected by a number of internal and external values, two externals being ambient temperature and pressure. Instantaneous ignition retard due to knock control might also affect maximum specified load. Misnomer, should really be something like "EngineMaxLoadCorrected"

EngineLoadRequested (rlsol)

Target load based on the accelerator pedal position. It is capped by EngineLoadCorrectedSpecified (rlmax_w) and will never exceed that value.