I would like an answer on this question from someone that is more knowledgable than myself. If you idle a gasoline engine, you always have to worry about carbon monoxide creeping into your cab or sleeper. There is no carbon monoxide threat when idling a diesel engine. My question is why not? I have heard several answers, from mechanics to truck stop theorists over the years. I once read an article that said diesel engines are about as close to 100% efficient as you can get, and therefore produce no by product gasses. I remember reading an article about a driver who died in his sleeper, and nobody knew it, because his truck kept running for days. It finally ran out of fuel and they found him dead from carbon monoxide poisining. I saw a follow up article days later, and it turned out the guy was driving a gas engine truck. Anybody know?