What does blue smoke from the car's tailpipe mean?
some people in my town have really rundown cars. some even have blue smoke coming out of the exhaust of the car. what does blue smoke from the exhaust mean? how come it was more common in the 1990's than it is today? there are only a few cars today with blue smoke coming out the exhaust but there was a lot of cars in 90's that had blue smoke coming out of the tail pipe?