some bypass oil filter systems have a heater to bring the oil to a high temp to evaporate moisture and fuel, in theory you never need to change the oil with these systems as long as you change the filter and top off the used oil at the recommended intervals. maybe we need something like this?

AMSOIL Synthetic Super Heavy Weight Racing Oil (AHR) is a high-viscosity oil designed for high-horsepower racing engines, typically supercharged and alcohol-burning or nitro-fueled, requiring a high-viscosity oil to resist the thinning effects of fuel dilution.

AMSOIL Synthetic Super Heavy Weight Racing Oil is formulated specifically for wear protection and friction reduction in the extreme conditions of racing. It is race proven and reduces friction, promotes power and inhibits wear.

The auto manufacturers now recommend thinner oils for their vehicles than in the past. Years ago, SAE 10W-40 was the most commonly recommended viscosity grade, later migrating to SAE 10W-30. SAE 5W-30 is most popular now, but Ford and Honda recommend SAE 5W-20. It is likely that more widespread adoption of SAE 5W-20 and other thin oils may occur to help comply with CAFE requirements.

Because of the change in cold-flow requirements and the fuel economy test pushing formulators toward the bottom of the viscosity grade, today’s SAE 10W-30 oils are more like yesterday’s (GF-1 spec) SAE 5W-30 oils. On top of that, there is a trend toward auto manufacturers recommending thinner grades. This seems ridiculous. SUVs and trucks, with their inherently less-efficient four-wheel drive and brick-wall aerodynamics, need powerful, gas-guzzling engines to move their mass around in a hurry. In response, auto manufacturers recommend using thin oils to save fuel. Incredible!

Thinner oils have less drag, and therefore less friction and wear. Right? Perhaps in the test engine or engines that experience normal operation. But somewhat thicker oils may offer more protection for more severe operations such as driving through mountains, pulling a boat, dusty conditions, short trips, high rpm, overloading, overheating and overcooling.

Any abrasive particles equal to or larger than the oil film thickness will cause wear. Filters are necessary to keep contaminants small. The other side of the equation is oil film thickness. Thicker oil films can accommodate larger contaminants.

Temperature has a big effect on viscosity and film thickness. As a point of reference, one SAE grade increase in viscosity is necessary to overcome the influence of a 20°F increase in engine temperature. At a given reference point, there is approximately a 20°F. difference between viscosity grades SAE 30, 40 and 50. SAE 20 is somewhat closer to 30 than the other jumps, because SAE 30 must be 30°F higher than SAE 20 to be roughly the equivalent viscosity.

Fuel dilution is quite normal in these rotary engines. Fuel dilution at this level is going to make short work of breaking down any type of oil. We would suggest running a 5W/40 in the winter, and then increasing the viscosity to 20W/50 during the hottest summer months. It would also be a good idea to try to drive on the highway as often as possible, in order to cook off any fuel dilution that may be building up in the oil.