There's an upside and a downside regarding major auto companies and the quest to develop vehicles with increased fuel-efficiency.

The upside: Auto makers are positioning themselves to carve out niches in fuel-efficient technology and design, The Wall Street Journal reported Monday (subscription required).

The downside: Auto makers appear to be exhibiting a 'herd mentality' on the current propulsion technology -- hybrid engine cars with both a modest electric power source and a mainstay internal combustion engine.

An electric hybrid focus

Following up on its successful electric-gasoline Prius hybrid, Toyota (NYSE: TM) announced it will make hybrid engine systems available on all models by 2020, The Journal reported. Meanwhile, Honda said it would import new hybrid technology to the U.S. to compete with Toyota and Ford (NYSE: F) plans to double its hybrid lineup next year, and Chevrolet's (NYSE: GM) Volt hybrid that will go on sale in 2010.

Economist David H. Wang said investors and consumers should not be overly optimistic or pessimistic regarding the sector's concentration on electric-fuel hybrids.