ORIGINAL: PaxMondo
Refining methods in the 40's were pretty standard across the board. The real difference lay in the crude. The US was refining at that time principally TX and PA crudes, which are considered quite "sweet". This means both light and very few impurities. The Venezuela and Mexico crudes imported at the time (and continue today) are the opposite, quite heavy and a lot of heavy metals => more difficult to refine.
Don't forget California. In the 1940s California was the #2 oil producer in the US. Pennsylvania was not producing that much at that point. It's early finds had mostly played out.
The largest single oil field in the US is in California (west of Bakersfield - Midway/Sunset) and the Navy owned a very large chunk of oil property until the 1990s. All the oil/fuel available in Los Angeles in game represents the oil produced from Bakersfield, Santa Barbara, and Los Angeles. The LA area as well as the Bay Area has many refineries to refine this oil.
In the 1940s most of the CA oil was light, sweet crude, but the stuff produced today is very heavy. Some of the refineries have been converted to crack the heavy oil so as to produce gasoline.
My sister is a petroleum geologist who was doing production in Midway-Sunset back in the 80s. I think she mostly works Canadian exploration these days.
US used those mostly for bunker oil refined along the Texas coast. Separate refineries were built just to handle those crudes.
Venezuela to this day is very dependent on the US for refining their crude. refineries specifically designed to handle Venezuelan crude were built on the US Gulf Coast. They've tried making deals with other countries to sell their crude, but they can't get a very good price because of the low quality and nobody else can refine it.
Mexico was one of the top producers in the Western Hemisphere for 60+ years. They too produced mostly light, sweet crude in the 1940s, but their production has been getting heavier in recent years. Their fields are also showing serious signs of depletion. A geophysicist friend said he was looking at Mexico's production numbers and they are falling off a cliff. In another decade they will be only a minor producer. The next question about Mexico is what they are going to do financially when the oil is gone.
Japan was of course working with DEI crudes in the main. [;)] Those are middle, not sweet, but not terribly bad either. So, in the refining process of then, yes, IJ AV Gas would have had more impurities. 50 hours though is neglible as far as the gas contaminants from the oil are concerned. 500 - 1000 hours maybe you will see some effects (metal fatigue from trace elements), but I'm not even sure of that. You have to remember that air engines get a lot more maintenance than your car and parts like cylinders are designed to be replaced. Also, war is hard on equipment. More likely to replace a cylinder due to war damage or over boost than due to gas contaminant.
The Japanese were predominantly using DEI oil because the US refused to sell enough to them. I think the DEI/Borneo oil varied quite a bit ranging from some light, sweet to heavy.
Aircraft engines usually had fairly short combat lives before they were pulled and rebuilt. To stay lightweight, a lot of aircraft engines made more use of aluminum. Aluminum did have some nice properties like very good heat dissipation (better than iron, copper is about the only thing better), but aluminum also is a soft metal with some properties that aren't so great.
Steel can take a given load indefinitely. If you put steel under tension, as long as it doesn't rust and it isn't enough to distort the steel initially, it will hold up to that tension pretty much forever. Aluminum in the same loading situation will start to crack and eventually shatter.
This is why aluminum aircraft are routinely checked for aircraft cracks. The Aloha Airlines 737 that had the top pop off back around 1990 had it happen because the constant pressurization and depressurization cycles weakened the airframe. (In a very ironic twist the day before that accident Boeing announced a new 737 convertible model which was supposed to convert between cargo and passenger load very easily).
https://en.wikipedia.org/wiki/Aloha_Airlines_Flight_243
Bill
