With an increase in outside air temperature, what happens to specific fuel consumption?

As the outside air temperature rises, the density of the air decreases. This reduction in density means that the air-fuel mixture entering the engine becomes less potent, typically resulting in a reduction of the engine's overall performance and efficiency. To maintain the same power output under these conditions, the engine may require a larger quantity of fuel compared to cooler temperatures, leading to an increase in specific fuel consumption.

Specific fuel consumption, which measures the amount of fuel needed for a particular output over time, reflects this increased demand for fuel as temperatures rise. In summary, the need for more fuel to achieve the same power output in warmer air conditions directly correlates with an increase in specific fuel consumption.