Hey! ---just to add to the confusion, I left the oil level in the rear drive unit filled to the bottom of the fill hole. I figured I would clean out the air filterbox when I started to see a film forming along the bottom seam- now about 600 highway miles later @ (50-65mph mostly) I don't have any oil from the rear drive unit vent hose going into the air box. The hose is not kinked or blocked- perhaps the synthetic oil I used does not foam or aeriate. I will check the air filter and box every 100 miles or so, but I think if it was going to happen it already would have, don't get me wrong I'm not trying to prove anything to anyone out there. I do R&D work at my work and some times I need to see what happens, as long as it's not dangerous or going to ruin anything (of my own anyway) .I do agree that the 180ml is the correct amount that should be used, and maybe that takes into account the different oil types, ambient temperature, unit temperature,oil temperature, expansion ,etc. But if I do not experiance any problems ,I like the idea of having an additional amount of oil in the drive unit (226ml vs 180ml). My P-250 is the "S" model 2008, although the rear unit looks the same as previous year models.
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