We have seen alot of problems with Rotella in the diesel direct inj motors. It's not what it used to be. Motorcraft seems to work well, I've used it in my wife's car for the last 80,000 miles, at 5000 it still looks new. I ran Castrol for a long time in my race engines with real good results and that was on alky. The last yr I raced I ran Brad Penn since my eng guy sold it to me for $60 case. I ended up putting it in my chevelle 434 sb street car after it was broke in. The Pennzoil plat. sync is suppose to be real good according to test I've seen, but I've had no experience with it. It seems like there is alot of stuff out there now that used to work great but now not so much. Quaulity isn't what it used to be, that's for sure.