Diesel Cars as a solution

With rising gas prices, diesel cars and SUVs are gearing up for a major American comeback after a brief appearance 25 years ago. But if all you remember are the smell and noise, you might not recognize the new leaner, cleaner versions. Back in the early 1980's, 80 percent of the cars Mercedes-Benz sold in the U.S. were diesel powered. General Motors sold diesel Oldsmobiles and Cadillacs. The reason then was obvious: Adjusted for inflation, the cost of gasoline then was about $3.15 a gallon. Buyers were looking for a more fuel-efficient way to drive.

Diesel engines were noisy, they were slow and they puffed out nasty polluting smoke. But they used much less fuel than gasoline engines, so buyers were willing to put up with the downsides.
As gas prices went back down, relative to other costs, and environmental regulations became stricter the tide of diesels rolled back across the Atlantic leaving only memories of clanky, foul smelling diesel cars. Today, while half the cars sold in Europe are diesels, diesel market share in the U.S. is about 3.5 percent and that's mostly pick-ups, according to R.L. Polk & Co.

With a hungry European market to feed, diesel development has continued, creating turbocharged diesel engines that perform better and pollute less. Today's diesel cars are virtually indistinguishable from their gasoline-burning siblings. Except they use a lot less fuel.
Diesel engines are more efficient than gasoline engines because diesel fuel contains more energy than gasoline. Diesel engines combust the fuel by squeezing air, which is warmed by a "glow plug," to extremely high pressure inside the cylinders. Just as the air is being squeezed to maximum pressure, fuel is injected into the cylinder where it combusts immediately in the hot air. That high-pressure ignition - higher pressure than gasoline could withstand - also results in more power.

These modern diesels have exhaust that, on a mile-to-mile basis, is close to gasoline in terms of smog-forming pollution. Already, because they don't need to burn as much fuel, they emit less carbon dioxide than gasoline engines. Excess CO² has been blamed for global warming.
Even with the new fuel, scrubbing diesel emissions this clean isn't cheap or easy. That's one reason most car companies are entering the market with diesel-powered SUVs first. Heavier vehicles have easier emissions standards.