Petrol cars don’t pollute any particulates – that’s a job left for diesels. I have to admit I was shocked to learn that the size (engine displacement) and RPM of a diesel engine altered the actual SIZE of the dangerous particulates…

Particulates seem to be “ashes” on a microscopic scale, I believe. Gasoline vaporizes and ignites, then the Hydrocarbons and Carbon Monoxide and Oxides of Nitrogen pollutants get burned up or altered and made into CO2 and H20 in the catalysts. Diesel spews out amounts of HC, CO and NOx, but also particulates – and catalysts cannot actually clean it all up. Hence, particulate traps (with periodic fuel enrichment regimes to burn the stuff out – all computerized engine control operated) and urea injection (literally kind of like peeing into the exhaust) are needed to even remotely make most car diesels legal for the ultra-strict US standards now in place for CARS.

I still get to “enjoy” sharing the roads with the massive pollution of idjits with massive 3/4 ton Dodge pickups and Cummins diesels, with extremely smelly exhausts and exhaust pipes the size of stove pipes. The “new” low sulfur diesel fuel notwithstanding…

Slow Atlanta-like traffic with a billion lights, SUV’s and idiots and me on my motorcycle trying to stay alive and not breath the SUV stink.

Why do they put sensors at all the lights in the city but don’t program them to do a damn thing?

At least we don’t have any water restrictions, so we can drink all this nasty polluted(paper mills are super polluters) water all we want.

It sounds like you may have moved to the southern part of the state.

re: particulate size. I was under the impression that the particle size was bigger on diesels than on petrol? Mind you, you’re still right that hybrids are better because when a diesel idles in heavy traffic it is still burning diesels and pumping out fumes. On a hybrid, it’ll be idling on the electric motor which doesn’t emit. I’m sure the petrol engine kicks in went it “senses” highway driving? The electric motor is designed for “stop – start” driving (i.e traffic).

Did they consider at all that some people actually don’t live in a big city? I live in a city a little under three times larger (land area) than Los Angeles, but with only ~125,000 population. My commute is one of the most relaxing, calm, stress-free parts of my day.

I was in Scotland on “holiday” 2 1/2 years ago, and put on the “telly” for 1/2 hour total for my time in the UK, watched BBC news. Coincidentally, there was an article about diesel particulates. The scientist quoted stated that high speed diesels (read: automobile diesels) were FAR worse for humans, because the size of the particulates was smaller – and more easily taken up by the body through the lungs. But as this article mentions, diesel trucks also spew out a lot of harmful particulates, small enough to enter the human body.

At least I feel better now that I ranted!