Ok so my truck has 77,xxx miles on it, and i when on a trip up to the U.P. the other weekend. When i was filling up on the way back i checked the oil to see if it was full. Well it was down about two notches so i add a little oil, got home let it sit for a while and checked it that night and it was down to about the same, took anther trip out to visits a buddy and same story. is this common or what? there isnt any oil leaks that i can see from, and it seems like am putting the same amount in ever full up now(were before it would be full when i checked it). i did read online that if you switch oil brands or maybe it was synthetic it could take the truck a few hundred miles to get use to and may burn oil, is this true? because i did swtich form castrol to delo oil. Any help would be very much appreciated!!!