i used to do all the work on my bmx bike when i was in elementary school, i used to use car motor oil on it(when i didnt have brake cleaner or something else that sucked for lubrication. hey i was a kid and didnt know what i was doing!) . it attracted so much dust and gummed up. i did hit the dirt track everyday after school.

mobil one might be better since synthetic motor oils repel crust and debris better, but its damn expensive, although i suppose 7-8 dollars isnt alot for a quart of bicycle lube.