Blue smoke
 

I just got my 07 ms3 a couple weeks ago, my dad picked it up for me while I was at work and filled it with regular fuel not knowing any better. I now have premium in it and have been avoiding the boost for the time being but I just noticed some blue smoke when I take off. Could that be from the regular fuel or should I be worried about something more serious?

Few reasons, read up there are huge info from this forum. My guess is, its coming from your turbo oil seals. common problem with a K04.

Yes, read up. Blue smoke is oil, most likely like @MRR; said, black soot is fuel, not that regular would do that either? Maybe if it caused you to run richer due to knock....

Several solutions to the smoking turbo.... search for that :-)

07 on a K04, I would assume blue smoke is turbo, as others said. Time to bigger! Wouldn't hurt to go ahead and compression and leak down check the motor though.

I would definitely run a leak down test just in case. Probably the turbo, though.

Does it smoke at idle or just when you "take off"? Either way it is oil. Could you be more descriptive of the conditions in which this occurs. Range of possibilities run from relatively benign turbo seal leak to serious engine ring blow by or worse.

I agree that you need to at least do a static cylinder compression check on a warm engine. Have to pull the IC off the top, remove the plugs and test each cylinder individually. Write down the numbers and post them. Also look at each plug and take a photo of the tip. If it is oily, that is not good news. If you haven't done this already, you need to do it periodically on an older engine, anyway.