With cleaner technology and higher gas mileage, diesel engines have been making a big comeback.
But now there may be a setback.
The World Health Organization recently issued a warning that diesel fumes cause lung cancer.
There has long been a suspicion of this. However, a new study involving non-smoking miners who were exposed to the fumes showed that they were seven times more likely to contract lung cancer than other non-smokers.
Diesel is used in all types of equipment from trucks to trains to ships, cars, and farm equipment.
Yet, a lot of people who work with or around the fuel had no idea of the WHO's new declaration.
"First time I'm hearing about it," said tow truck driver Antoine Wheats. His truck runs on diesel.
"It's something to think about," he said. "You've got to be very careful. It's something to think about."
Wheats is not alone.
Most of the people 11Alive talked to didn't know that the fumes are now considered as carcinogenic as second-hand cigarette smoke or asbestos.
Still, experts say Americans are not likely to be at the same kind of risk as those in countries with inferior or outdated diesel technology.
That may be why most folks we talked to weren't overly worried about it.
"It sounds bad, of course," said Atlanta resident Matt Liotta. "But I'm more worried about getting into an accident on our highways than I am about smelling the fumes of diesel trucks."
Liotta runs a company called PodPonics that offers a greener alternative to traditional farming by growing food in urban settings near its point of consumption. It lessens the need for long-haul trucking in general and the fuel that goes with it.
"I think in general raising taxes and other things to lower fuel consumption would be better for everybody," Liotta said. "So I think things like that would lower miles and ultimately lower the environmental impact of the exhaust."