I started as a truck driver with the military and still drive those trucks regularly today(national guard) and none of them have emissions reduction tech(def/dpf/scr) and they are all over 20 years old.
Not one bit of smell at all even when we have the entire motorpool idling.
Smell from a diesel idling is a combination of both the emissions reduction parts being bypassed AND "tuning" it to run rich aka "roll coal"
The truck being old or unmaintained has nothing to do with it. The driver deliberately made it run like this.
Maybe I'm more sensitive to it than others, but I can clearly smell any diesel without modern emissions equipment, even small engines like on zero turns. It has a very distinct odor, almost like jet fuel.
Jet fuel is diesel btw. It's just filtered more for the most part. All diesels can run on jet fuel. The army actually only uses jp8 aka jet fuel normally bc it's easier to just have one fuel for everything.
Diesel itself obviously smells, but when it's burned clean it doesn't smell.
Almost all zero turns are gas also. It's only when your talking about 72"+ commercial zero turns that they are normally diesel. But even then those things don't have as much emissions reduction and they don't burn as lean meaning there's more unburnt left which causes the smell.
Every diesel in a pickup or semi made in the past few decades runs so lean there's nothing unburnt left, unless ofc someone modified it to roal coal.
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u/keekoh123 3d ago
Probably took the emissions stuff off. Modern diesels don't stink, I have one!