 I'm with the Diesel Technology Forum. We're a not-for-profit educational association. We educate about the environmental progress of clean diesel technology. Diesel has transformed as a technology. A lot of people think that it's a dirty old technology, but it's been transformed from the technology of the past. It's very clean, smoke-free, near-zero emissions. And then that new technology is being applied to the legacy group. Diesel is also very long-lasting and durable. So it's being applied to the legacy fleet to clean up that as well. It's one of the most cost-effective ways to improve air quality in areas that are having problems with non-attainment air quality issues. So is it fossil fuel? But because of the advanced technology engines, they process the fuel so much more efficiently than before. And then also back in 2006, diesel fuel itself underwent a transformation. They became ultra-low sulfur diesel fuel. They took the sulfur out of the diesel, much like they took the lead out of gasoline back in the 70s. So the fuel itself is very clean. The engines process the fuel much more efficiently, and then the emissions controls trap anything else that the fuel, the engines have it fully processed. So the air coming out of the engine, we often do a weight-hankerset test. We'll put a weight-hanky on the end of an exhaust, and it comes out clean, it smells clean. There's no visible smoke or emissions. It's still clean.