Short of employing a full hybrid system, automakers are finding many ways to improve fuel economy in current, gas-engine cars. Engineers are looking at every part of the drive cycle to determine where savings can be made.
Some of the technologies being employed are old, such as turbochargers and continuously variable transmissions, but they are being refined to take advantage of new materials and computing power.
There have also been some newer innovations that cut fuel use, such as the use of idle stop and dual-clutch transmissions.
A number of factors are helping push these developments. Consumers are trying to cope with increasing gas prices, and governments are pushing for reduced carbon dioxide emissions, which relate directly to fuel economy.