Recently my buddy Rex noticed oil pressure fluctuations on his brand new Rotax 912ULS. He has the Grand Rapids Technology EIS and the housing of the oil pressure sender on his new engine is physically different than the VDO I have. However the pipe thread that goes into Rex's oil pump LOOKS the same as mine.... today is the first I'd heard that Rotax had changed this pipe thread. I'm not sure I believe this, in fact. Whatever, I removed the "new style" sender from Rex's brand new 912 and screwed in a small mechanical gauge which is 1/8-27 NPT. Went right in, didn't leak. Also the VDO sender (P/N 360-004) is 1/8-27 NPT, says so right on the package. (I keep a spare on hand, I've had to replace a couple of these already. If you mounted the sender remotely as the instructions tell you to do, rather than screwing it into the oil pump the way Rotax does, the sender might last longer.) Long story short, I attach a photo of the 360-004 sender and the 1/8-27 NPT mechanical gauge screwed into a 1/8-27 NPT tee fitting. Note that this is the exact same mechanical gauge that was temporarily installed in the new 912ULS, and the VDO sender is an exact replacement for the one in my 2006 912ULS. From all the above, I conclude the female thread on the Rotax 912 oil pump, old (my 2006) or new, is 1/8-27 NPT. Take it for what it's worth. BTW, VDO is very adamant that the 360-004 IS NOT FOR AIRCRAFT APPLICATIONS. Good old Rotax.