Lower diesel prices have helped European car makers in recent weeks. Prices have fallen below gas prices as the economic slowdown has hit the transportation industry resulting in lower demand for such distillates as diesel and jet fuel.

On Wednesday, AAA reported the average price for a gallon of diesel at $2.63 a gallon compared with $2.68 for regular gasoline.

Meanwhile, the German manufacturers have been launching a promotional assault with their clean diesel vehicles: Audi with its Q7 SUV (an A3 wagon is due later this year); BMW with its 335d car and X5 SUV; Mercedes-Benz with its ML, GL and R-Class SUVs; and VW with its Jetta sedan and Sportwagen.

An Audi TV ad focuses on patriotism through fuel efficiency, showing barrels of crude oil rolling down country roads and city streets until they gather to roll up the gang planks of an ocean-going steamer presumably bound for the oil producing nations from whence they came.

Diesel prices are now edging up but hopefully their comparative parity with gas prices will continue to provide an incentive to consumers to try out the new diesels which are clean, quiet, powerful and very fuel efficient.

There's a reason that half of the cars in Europe now run on diesel.

- Peter C.T. Elsworth