Picked up the new 2005 Prius and I was getting, no AC and windows cracked, up to 54 mpg? This is fairly long distance, over 50 or so miles, including some highway.
It was perfect weather, something like 65, so no need to run the AC, and I have seen numbers close to that with my roommate's 2007 in similar situations. The heater and AC really rob gas mileage with Prius. Only reason I was asking was due to a history lesson. The naval aircraft during the Battle of the Philippine Sea had their engines turned to run incredibly lean and my understanding is that it did a lot of damage to the engines. Of course those were high powered radial engines fed by pressurized carburetors, not an advanced computer controlled fuel injection system.
In my experience, with an ambient temperature of 65ºF, running the A/C will make no material difference to the gas mileage. All things being equal. It doesn't make sense to be hot/cold when you could be comfortable, just to "save a few MPG" You will save more MPG on the highway by having the windows closed and the A/C on. If the OAT is less than 10ºF or greater than 81ºF, then the A/C will make some difference, but in these conditions, it is better to be comfortable.
I guess I'm curious to read more about that. Carbureted aircraft engines don't enjoy computer control, but they do have live mixture enrichment tools available to the pilot. Different operating conditions call for different mixtures, so there's a big lever on the panel to let the pilot set that mixture however they think is best. Typically, the pilot observes a temperature reading taken from one or more of the cylinder heads when attempting to find the lean end of good operation. Not like a car engine where the mixture is more or less locked in by a mechanic during a tune-up. I might hazard a guess that a decision was made to fly on a lean mixture to maximize range or airborne endurance?
I am pretty sure that it was mainly the Dauntless dive bombers that were sent out beyond their official maximum range. When they were coming back to the carriers, they were on the edge of fuel starvation.
