Diesel powered cars have already proven to be just as efficient as hybrid-electric vehicles, and in some cases better, but until now the oil burners haven’t been available because of strict clean-air regulations in some countries. Reuters is reporting that one of Toyota's top engineers has said that making a diesel-powered vehicle that would clear the regulations would make the car too pricey to be worth the fuel savings.

"I won't deny that we won't be offering a diesel in the US sometime in the future," said Executive Vice President Masatami Takimoto, who oversees Toyota's research and development. "But right now we think hybrids are much more cost competitive," he told reporters on the sidelines at the Detroit Auto Show.

Japanese rivals Honda and Nissan have already confirmed that they’re working on clean diesel powertrains for launch by the end of the decade. Particulate filter traps and other added components would push the price past that of an equivalent hybrid, at least in the US. Takimoto added that plug-in hybrids were a better option.

This could all just be because Toyota is actually lacking in terms of diesel technology compared to the other large carmakers. Recently the company paired up with Isuzu to do-develop a new range of diesel engines. It’ll be interesting to see what their future plans are.