Either way, black diesel smoke indicates a problem that needs immediate attention. Meanwhile, blue smoke means the engine ...

However, blue smoke means there is more of it than there ... Black and blue smoke are more common in diesel engines, and there's a dedicated article explaining why it occurs.

While white smoke coming from your exhaust could be due to condensation on cold mornings, a smoking exhaust is often a sign of something wrong. Blue smoke typically means your car is burning oil ...