the difference is when you take a walk in the city or in a car tunnel without proper ventilation, the generator would be placed outside, and you wont have another 100 000 of them passing by every day. diesel and gas is now basically industrial waste and sewage, thats one of the reasons why it smells like shit. i suspect that they shit in the fuel on purpose to make us hate it. rudolf diesel would spin in his grave if he knew what they sell as "diesel"