I just recently put a rebuilt ej251 block and phase 1 2.2 heads with delta 230 hp cams into my 96 impreza 5 spd wagon. I put in supertech 10w40 with 4 oz of lucas ZDDP additive and let it idle for around 10 to 15 minutes right after start up to watch for any leaks and funny noises. Took the car out and preceded to break it in using 2nd gear pulls and a few 3rd gear pulls with engine breaking in between pulls. Put 18 miles on the engine and came back and changed the oil right away due to time and being at night with supertech 10w40 and purelator PL14460 white oil filter with another 4 oz of lucas ZDDP additive. Let it idle for 5 minutes then took it out and did more 2nd and 3rd gear pulls and engine breaking on the way back to the house.
Changed the oil at around 650 miles and decided to try the supertech hm 10w40 (purelator white PL14460 oil filter) and added 2-3 oz of the lucas ZDDP. Put maybe 75 miles on it before taking around a 600 mile trip mostly freeway driving at around 75 mph and times to 85 mph. Was varying speed at times when I could and such. I have a bit over 1000 miles on the supertech hm 10w40 right now and going to be switching over to valvoline maxlife 10w40 high mileage here shortly. I had added like 1/4 quart in between the first and 2nd oil change but haven't since then. The oil level has been solid at the full line. I have 0.002 bearing clearances so hence the 10w40 if you guys were wondering...
Any way, when do you think I should change the supertech hm out? Maybe another 500 miles or right away? I do mostly city driving and some highway and some 50 mph runs now but try and drive long enough so the oil gets up to operating temp. Going to run the maxlife 10w40 HM for maybe (2 or 3) 2.5k oci's and then switch over to the T-6 5w40. So, a total of maybe 7500 - 10k miles before switching to synthetic.
But, why I am posting is that I just sent a request to Blackstone for an oil analysis sample kit and will be sending in a sample of the supertech hm 10w40 here soon and will be posting the results here.