I was driving along I-20 last week and saw an older Chevy, I am assuming 6.5L diesel, pulling a 3+(didn't count, but it was still fairly long) horse trailer. You could see the smoke billowing out from the tail pipe. I think I used the wrong word, billowing was not it, it was sending a stream of smoke out 20 feet to the side. Poor guy in a car had to pull over and get out, I think car problems. He was standing outside of his car as this smoke machine went by him. It looked hilarious in my mirrors.