I tested the air temperatures on my Plus8 by fitting my OBD meter and going for a run. I measured incoming air temp. Ambient air.....15degC Incoming air....35degC and still rising slowly. The intake is at rear of the engine pointing generally towards the side louvres but a gap back. The exhaust manifold is below. I used a thermometer once to measure the surface temp of the polished stainless filter box..48degC! Basically, cold air is denser than warm. The ECU senses this and adds more fuel to match this so a small power increase is obtained. The explosion in the cylinder with denser cold air is a bit more powerful. Think of the principle of a turbo or supercharger supplying more air and how an intercooler works.
