The California Air Resources Board (best known by its catchy acronym C.A.R.B.) has been regarded by many enthusiasts as the bane of their existence. After all, what good could come of a group of environmental activist liberal bureaucrats cloistered in an ivory tower in Sacramento?

Okay, they can take some credit for the demonstrably cleaner air in the greater L.A. area despite the exponential increase in the number of vehicles and population since the 1970s, the nadir of air quality for the region. Those of us born before the Reagan administration remember the dark early days of smog control, with engines choked by restrictive pellet-bed catalytic converters, unreliable electronically-controlled carburetors, and laughably anemic outputs of large-displacement engines. (Say, a pulse-pounding 160 horsepower for a 350 cubic-inch V-8?) Left-coast enthusiasts rightfully cursed the heavy-handed bureaucracy for forcing the hands of the automakers to cut power outputs in half nearly overnight.

But after the automakers whined about the “impossibly strict” regulations, they figured out how to give enthusiasts the best of all three worlds: economy, performance, and clean emissions. Evidence? When using modern power measurement standards, the 400-horsepower Corvette LS2 V-8 rivals the output of any 60s-era muscle car and gets nearly 30 miles per gallon. The idea of a normally-aspirated engine producing more than 100 horsepower per liter was considered the domain of purpose-built race cars not long ago. Yet Honda now routinely produces such engines in production vehicles.

In some ways, we’re seeing history repeat itself with the new-generation of clean diesels. The OEs are clamoring to get these thrifty, fun-to-drive models to market, but now have to contend with new emissions regulations that don’t differentiate between gas and diesel.

The conundrum is two-fold. Firstly, American diesel fuel, up until recently, had a relatively high sulfur allowance of more than 500 parts per million (ppm) which is still considered “Low Sulfur.” Soon to be mandated is ultra-low sulfur diesel, which only allows for a minute 15 ppm. Eliminating sulfur in the fuel will allow for the use of more diesel catalyst technologies. The reason Europe has seen rapid and prolific development of diesels over the past few years is European regulators concern is carbon dioxide output. C.A.R.B. and the EPA, on the other hand, look at particulates (soot), NOx, and a variety of other pollutants.

So OEs now have to design for an entirely new set of standards which in some ways mirror the clunky measures adopted in the 1980s. DaimlerChrysler is awaiting regulatory approval on its urea-injection catalyst system. The EPA and C.A.R.B. have rightfully asked “so what do you do when it runs out?” But seeing as a full reservoir of the stuff should last upward of 6,000 miles, topping off the tank will likely become as routine as changing the oil. The other technology is essentially a “blast-furnace” catalyst that traps particulates and obliterates them with thousands of degrees of heat. As odd and Goldbergian as these measures seem now, I’m sure that, in a few years, much more elegant and integrated solutions will be implemented, and the early days of the “new diesel” will be but another interesting chapter of automotive technological evolution.