What a load of tosh!!
Cooler air takes more time to heat, the initial cooler air is denser. 10deg less AIT at the filter will have a major impact in the AIT at manifold and recovered air density. Ideal on all setups would be 15-30deg AIT with ambient around 20deg
Its not for bit of power,
Lower the air temp one cruise the more timing the car will run based on air delta correction timing maps, more timing give more effective efficient combustion stroke which will give much better mpg and aiding egt cooling from the ignition angle being optimised, As soon as the ecu sees 40deg+ air the ecu pulls out the timing, on wot cruise and light acceleration. The reason manufacturers work hard on decent cooling
From a well respected tuner