I took #2832 in for my free oil change at the dealership yesterday. I had to wait 20 min. to get it in so I was just looking at cars in the lot. When I went back to the waiting room my car was on the hoist and the guy had just started draining the old oil. I'm just kinda watching him. He changes the filter, lowers my car and then grabs the oil gun. Just before he starts filling her up I stick my head out the door and say, "You're putting 5W20 in there, aren't you?" He rolls his eyes at me and lumbers back to a closet, hauls out a box of qts of 5W20 and starts pouring 'em in. If I hadn't been paying attention I would probably have had 10W30 in there. Maybe it would be OK, maybe not. Did he do it because he thought I wouldn't know the difference or was he just lazy? Either way, I doubt I'll be changing my oil there ever again.