The first oil change of the 2007 has occurred (5034 miles). I had the OEM oil I drained out analyzed. The significant readings are: Ccpper: 79 ppm (as opposed to the 1 to 2 ppm expected) Boron: 1 ppm (as opposed to the 3 to 20 ppm expected) Silicon: 190 ppm (flagged as high) TBN: 4.03 So far, by looking at others spreadsheets: http://priuschat.com/forums/showthread.php?t=35544 http://priuschat.com/forums/showthread.php?t=26589 it seems that copper is an additive of the OEM oil in the Prius and boron is an additive of US oil (at least Mobil One). The silicon is high. Glad I changed the oil and filter to get all the dirt out. Now the extended change intervals start with 5k oil analysis using Amsoil 0W-30 and Amsoil filters.
There may be copper in the lubricant used on the bearings during assembly to prevent galling of the bearings during first start up. I always used molybdenum grease and oil when rebuilding an engine to lube the bearings until oil pressure built up. There may also be copper in lubricants used on fasteners in the engine. I think silicone may come from sealants used in assembly. Just having a stab mind you, other experts here will know more.
Patsparks, it had never occurred to me that copper might be a lube additive from the Toyota factory. I always supposed that it was an indication of break-in wear. In either case, I would expect that Fl_Prius_driver will have much lower numbers next time around.
The only way to know for sure if the Cu is an additive is to get a virgin oil sample. WIth the oils I use, Cu is clearly not showing up. With my FJ Cruiser, I sampled the oil at 2,237 km. AL was 9, CU was 48, Si was 187, and TBN was 2. Viscosity had sheared to 8 cSt. Yes, I had the oil changed based on those number I refilled with a dealer Valvoline 5W-30, as it was a complimentary oil change. After 6,041 km sampled the oil. AL dropped to 4, CU to 7, and Si to 32. Unfortunately the viscosity had sheared to 7 cSt. Went to Esso XD-3 0W-40 and it remained very stable. Recently tried Mobil 1 5W-20 as a "winter" oil, should get the results back soon to determine if it is holding up. If not, Esso XD-3 0W-40 year round
There are industrial lubes that contain Cu as part of the anti-seize properties. Loctite makes several such lubes that you brush on.
That's the sort of thing I was thinking about. Hey it may not be assembly lube but who knows? I can't think of anywhere copper is used in an engine where it isn't covered by a layer of grey metal.
If you look at the second spreadsheet in the original post, all the OEM Prius samples had a lot of copper but none of the samples after the first oil change. I certainly hope that this is the case, since I do not know what would be in the engine that would give those readings.
During my 1st oil change, I noticed that the oil was just different(color and texture) from any other oil that I have encountered whether in the automotive or aviation industries. Seemed to sort of smell and feel .. (sort of)... like Synthetic turbine aviation oil but more slippery. I'm guessing that it is a Toyota special formula break-in oil.