Why does NJ DOT ban idling Diesel >3mins. at convenience stores? Lately I have seen these Notices at the cash registers of every Wawa I stop at for coffee." YOU CAN BE FINED UP TO $3000 FOR IiDLING A DIESEL FOR MORE THAN 3 MINUTES..." I am not disagreeing or protesting this. I am simply trying to educate myself. Do our diesel produce high concentrates of S04 at prolonged idle? Are diesels environmentally unsound at prolonged idling because we run "cooler" than gas engines and don't combust fully at idle? I just want to be able to prepare myself the next time someone asks me..