[9phil9]

The ECU adjusts the air/fuel ratio to set factory tolerances.
Your engine does not run leaner or richer based on intake air temp, once it is up to running temperature.

Your so called empirical data is laughable because you forgot to figure in transmission and differential temperature, tire temperature, wind speed and direction...ect.

When the ECU is correcting for air/fuel ratio and the incoming air is cooler, it simply adjusts to a ratio that maintains the correct set ratio.

The benefit of a cold air intake is increased HP, because the engine can take in more air, and thus, more fuel, at the same rpm.

Given the exact same outside temp and load conditions, an engine will return slightly better fuel economy when it takes in colder air from the front side of the radiator.

AND....that's why factory engineers, with a Graduate Degree, have been designing cold air intakes for most late model automobiles and trucks.

If your silly idea held any merit at all, then all modern engines should be drawing intake air from inside a shroud, that is wrapped around the exhaust manifold. lol