Well anyways this might be just a temperature issue but I'd figure I'd get some insight. I gotta 08 hemi and yesterday I got an aero turbine 3030 single exhaust. It was just a simple cut out drop in of the old-new muffler and still retains the resonator. My wife told me that my truck was blowing a thick gray smoke out the tail when I gassed it abit while parked. It has been in the teens here in Texas the past couple days and I don't know if maybe it's just the cold weather. I ran my jeep that was parked next to the truck which also has a hemi and gassed it a little. I didn't notice that it had the thick gray smoke that my truck did. I may be acting paranoid but I was wondering if anyone knows if it is normal and just weather related from the guys who are up north and used to cold weather. I'll keep an eye on it and if it gets darker I'll post the results.

 

It has been in the single digits here and I have had thick white exhaust. I get it when gassing until the exhaust lines heat up. It is probably just the temps especially if you don't run it long enough to heat up the exhaust lines. The water made during combustion will condense from previous runs.

 

Yeah I would think it is a lower ambient temperature issue right now. Wait until it warms up and see then

 

White vapor smoke...condensation from being cold. Becomes very flashy and thin at higher temps and then gradually dissapears. It was so cold here in NY last week that my entire car ride, all you seen was puff of white smoke from everyones tailpipes. like they were burning 5gals/min of hot water or something...lol Didn't matter fully warmed or bone cold, they all had smoke stacks. It was crazy cold. (-*27F) at 7am.
Anyways,
Gray smoke. Either running a little rich from the pcm dumping lots of fuel to get started or your prob just burning off those carbon desposits from revving up your motor to hear the sound.
Blue smoke is another ballgame.

 

Probably just burning off greases and such in the new muffler combined with condensation.