spyked

Hi everyone. 2013 C250 CGI here. 2,000 miles. Everything running great. I do notice that if I'm driving at speed and need to "floor it" (resulting in kick-down) I can see a small puff of black-ish smoke come from the tailpipe. I notice many cars do that, so I'm not concerned. Just a reaction to lots of gas being introduced quickly (I've been told).

**I also notice that, at start up, only after sitting overnight, for around 10-15 seconds, gray-ish smoke comes from tailpipe. Anything to be concerned about? Car has oil, runs perfectly. Is it just burning off crap from the muffler or something along those lines?

I'm more curious about it than concerned...it's a lease so I don't really care...but just thought I'd see what other C250 drivers think.

Thanks.