California has been leading the effort for ever-lower vehicle emissions standards for decades, largely due to smog problems in the Los Angeles basin. A unique confluence of factors makes L.A. particularly susceptible to smog. The eastern edge of the basin is ridged by the Transverse mountain ranges, which often cause temperature inversion layers that trap exhaust. Combine that with a dense population, a heavy reliance on automobiles, and a large port and you have a recipe for smog. And since L.A. gets essentially no rain from May to October, there is nothing to provide relief.
As a southern California resident, I am glad that the significantly reduced emissions from cars and trucks—driven by standards from the California Air Resources Board (CARB) and the U.S. Environmental Protection Agency (EPA)—has literally cleared the air. The number of Stage 1 smog alerts in Los Angeles has declined from over 100 per year in the 1970s to almost zero now.
While CARB continues to plan for increasingly lower emissions standards, a recent study by UC Riverside suggests the agency should start looking elsewhere for emission controls. According to Bill Welch, principal development engineer for the study at UC Riverside’s Center for Environmental Research and Technology, emissions from commercial charbroilers, used to cook hamburgers and other food, emit more than twice as much particulate matter as all of the heavy-duty trucks in California. In fact, Welch said, “an 18-wheeler diesel-engine truck would have to drive 143 miles on the freeway to put out the same mass of particles as a single charbroiled hamburger patty.”
Over the years, the automotive industry has made incredible strides in reducing particulate matter and NOx emissions. However, a significant need still exists to reduce CO2 emissions and improve fuel efficiency. The Achates Power opposed-piston, two-stroke engine—currently being developed for commercial and passenger vehicles—is already calibrated to meet today’s global emissions standards (with conventional aftertreatment) while demonstrating significant fuel efficiency advantages. Perhaps now that we’ve proven this can be done, regulators can maintain their focus on reducing CO2 emissions and redirect their efforts on particulate matter reduction to other things (such as charbroilers!).

Clean Diesel Engine Emissions