Engine load refers to the amount of effort required by an engine to overcome external and internal resistances. These resistances can include accelerating the vehicle, maintaining speed, climbing hills, overcoming internal engine friction, and powering accessories like air conditioning and the alternator. A dynamometer (dyno) can also simulate load by applying brakes to the flywheel or wheels.
When an engine experiences an increase in external load, it demands more effort from the engine to maintain or increase speed and acceleration. To achieve this, the engine must produce more torque. Increased torque production requires burning more fuel, which in turn necessitates a greater intake of air. Therefore, in the context of engine tuning, engine load is often measured by the amount of air entering the engine for combustion to generate the necessary torque.
Opening the throttle wider increases engine load by demanding more effort. Similarly, changes in manifold pressure (vacuum or boost) reflect engine load. Higher air pressure (or less vacuum) indicates a greater demand on the engine. For tuning purposes, increased load translates to more air inside the cylinders.
In summary, engine load represents the effort required by the engine to overcome resistance. This resistance can come from various sources, both internal and external. Understanding engine load is crucial for tuning and optimizing engine performance.
