Hello all, I need your advice/thoughts on this: I bought my Ford T-Bird(1997, 4.6L) with 72,000 miles on it, and used mostly 10w-40 regular oil(motorcraft/pennzoil). It never used any oil between changes, never had to add, and the level was ALWAYS perfect, never dropped a bit.( I drive about 60 miles a day, and live in TN.) At exactly 82,000 miles, I decided to switch to synthetic, and put Pennzoil full synthtic 10w/30 in it. After about a week/300 miles, I noticed a very slight drop of the level, perhaps 2-3mm . I wasn't scared, 'cause I knew it was usual for syn. oil to be "used" more than reg. oil, 'cause it's "slicker" and that I was also using a lighter weight. However, after 2,600 miles on the syn. oil, the level dropped further, and came down to the exact middle between the "add" and "full" marks.(I had to add exactly a half quart, and after that it's fine, the level I mean). this scared me a little, although the car ran just fine, and i never noticed anything abnormal. I talked to several knowledgable people and all told me it was normal to use a 1/2 quart in 2,600 miles, especially syn. oil. I checked for leaks, and didn't see any oil drops on the ground or on/in the engine., so it seems, that the syn. oil was "used" more than the regular oil. Also, the syn. oil looked a lot dirtier, and I'm happy about THAT, 'cause the experts tell me that it has "cleaned" the engine more than the reg. oil. Can/should I go back to my regular Pennzoil or Motorcraft 10w-40? Have I created leaks that I cannot see somehow? Or was that amount of oil jsut "used"? What do you guys think? If I go back to reg.oil, should I use a "high mileage" type? Any feedback is very appreciated... -Nishan.