Mr. Hart also suggested that Exxon Mobil was considering diesel investments at other locations in Europe, where the company has nine refineries and is second largest in the industry, after the French giant Total.

From its network of refineries in northwest Europe, Mr. Hart said, Exxon Mobil will collect heavy fuels for which there is no longer much demand — like the so-called bunker used by older ships — and carry it by boat to Antwerp. There, a new refinery unit will distill the gooey substances into diesel and a similar lighter-weight fuel used by more modern ships. The company will then sell the diesel in northwestern Europe, which now imports large quantities of the fuel from the United States, the Middle East and Russia.

Exxon Mobil is trying to catch up with a powerful trend that was initially encouraged by lower taxation on diesel cars and fuel, and then grew with big improvements in European auto design.

Image A BP gas station in Belsize Park shows the price differential between regular unleaded fuel and diesel. Credit... Tom Jamieson for The New York Times

Carmakers in Germany and France have developed popular diesel versions of the Volkswagen Golf, the Audi A4, the Renault Clio and the Peugeot 308, allowing diesels to grab around two-thirds of the new-car market in France, Spain and Belgium, and about half of that market in Britain and Germany.

“The European manufacturers are the market leaders,” said Oliver Waschilowski, who follows the car industry for IHS in Essen, Germany.

In bygone days, many drivers disdained diesel cars as being pokey and for emitting smelly fumes. But thanks to a string of improvements, diesel vehicles are now considered high-performance machines.