Hello, Some of you might remember my recent oil consumption problem with switching to synthetic (pennzoil 10w 30) from non-syn. oil(Pennz. HM 10w-40). So, I'd like to try a heavier oil in my T-bird'd 4.6l v8 modular motor (85,000 miles). I want to get a good oil that's not TOO heavy for this motor, and an oil which is availble at a normal store, not mail-order oil. So far I've considered: A) Castrol syntec 10w-40 (a little scared of this one 'cause it's synthetic, which might damage my old seals/cause them to leak more?? but I've heard it's good; A3 and all that..) B) (back to) Pennzoil High Mileage 10W-40 C) Motorcraft 10w-40 (regular) I've used both B and C with ok/good results. What do you think? which is better suited for my purpose? Pls help, I really need to make this decision soon...Thanks a lot in advance. (if it helps your feedback: I live in Tenessee, drive ca. 50 miles a day, use Motorcraft FL-820S filter, change oil every 3K miles.) -Nishan.