well, I'm itching to change the oil on the 97 Camry. In there now is a 50/50 blend of XD-3 20W20 and Tech2000 (S-K) 0w30 with 7400KMs (less than 5K miles). It was just installed end of summer 08 and went right through the dead cold winter. 90% is city, 10% hwy. The valve cover gasket has been repaired twice; first I tried resiliconing the old gasket, but it was hardened and flattened, so it was replaced again with a new one. I poured two cans of "Wynns Engine Tuneup" in there to thin the oil during the coldest months and maybe clean some of the mess. All it is, is some type of Ketone or something. I noticed there was some major cleaning happening when I had the valve cover off, you could see the verious layers of varnish coming off, like layers of the earth seen at an archeological dig, it was really facsinating. There were at least 5-7 separate layers coming off, from what I assume were 5-7 diff oil changes with VII loaded oil before we got our hands on the car. This engine does fall under the sludger umbrella. The EGR had a problem with one of the switching solenoids, and the car randomly idled high, surged, stalled etc with the check engine light being on most of the OCI. Just got that [censored] fixed a couple days ago. Oh, I also experimented with blending diesel into the tank to see if it made any effect on mileage (it increased it a bit, actually) And I've been doing my trademark forced downshifting in full effect during this time. :D What do you guys think, is this enough abuse for the current fill? I mean despite the conditions and mileage, this particular oil blend has the valvetrain it's quietest, and the cold piston slap is virtually gone, even the -25C starts, out of all the oils I've tried in the past. The oil looks quite normal for this kilometrage, not soot black or anything, although it smelled a little bit like used diesel crankcase oil when I was mixing in the diesel! I'd like to get a UOA done, but not sure i wanna spend undue money behind this beast. Thoughts?