Just as an expected new wave of efficient diesel-powered cars was set to come to the U.S., several automakers are canceling plans for upcoming diesels.

Following news last week that General Motors suspended plans for a small diesel V8 for its light-duty pickups, Wards Auto World has confirmed that Honda has scrapped plans to put a four-cylinder diesel in the TSX sedan. Nissan has also reportedly canceled plans for a V6 diesel to go into its high-end Maxima.

These cancellations would leave German automakers Audi, BMW, Mercedes-Benz, and Volkswagen as the only car brands selling diesel passenger cars in the United States for now.

With cars sales volume decreasing, adding another powertrain variant to a model line is certainly something an automaker would have to carefully consider. Given the volatility in diesel prices over the past 12 months, ranging from about $5 a gallon last summer down to about $2 now, motorists may be skeptical whether the added cost for purchasing a diesel-engined car is a safe investment. While the fuel-economy benefits over traditional engines is undeniable, the price ratio for diesel compared to gasoline has proven quite varied.

Given the worldwide economic challenges and the impact on consumer buying behavior, it is natural for automakers to be timid about new initiatives at this time, but it is a shame for them to come so close to introducing a low-compromise solution to reducing fossil fuel consumption only to withdraw.

Also read “Why does diesel fuel cost so much?” and “Can diesels save money and oil?”

—Eric Evarts

Learn about driving green in the Consumer Reports special fuel economy section