The cheaper, more efficient fuel began to drive whale oil out of the market.

The car is expected to be lighter than the outgoing model to make it more fuel efficient.

Passenger cars, which are more fuel efficient than light trucks, continue to fall below 50 percent of the market.

However, the device actually made the car less fuel efficient.

Your dream becomes one about cheap, efficient, green and natural fuels.

The 787 has been designed to be 20% more fuel efficient than the 767 it is to replace.

Further, the base model will be more fuel efficient than the current version.

The engines are expected to be at least 30 percent more fuel efficient.

To produce less carbon dioxide, cars would have to be more fuel efficient.

Boeing hopes the new plane will be 17 to 20 percent more fuel efficient than the 767.