Jan,
My understanding of a road diesel is that they always run LOP (except when their airfilter is clogged and they are belching out black smoke) and the power is set by varying the amount of fuel introduced into the cylinder using the fuel servo (i.e. mixture control) and this is controlled by the power peddle (frequently and incorrectly called the throttle as it does not throttle the intake, but may throttle the exhaust to simulate the same peddle dynamic of a petrol road vehicle).
For an injected road vehicle, (electronic fuel injection) typically fuel is injected into a point in the intake manifold (or sometimes into the cylinders like aero engines). The amount of fuel injected is set based on the oxygen level in the exhaust to maintain a target mixture. As far as I can tell, this target is a rich of peak target in auto's. The power is regulated by throttling the intake airflow.
In aero engines we don't have computer mixture management systems. We also have two very different operating modes. A - Maximum sustainable power without regard to efficiency (i.e. climb power), B- Cruise power where we want maximum economy. A is set by default (all levers forward), B- Is set by hand. A further difference between auto and aero engines is that the air volume in an aero engine changes substantially without any change in engine settings as we climb and descend.