New study shows that diesel engines might trump hybrids in the near future.

What kind of vehicle will smart motorists be driving 20 years from now? All things considered, advanced diesel technology might hold greater promise for individuals and for society as a whole, compared with hybrids and ethanol-fueled engines.

Looking ahead to the period 2010 to 2020, the Rand Corporation—a California-based think tank—conducted a costbenefit analysis of all three types of powerplants in three different vehicle types: mid-size cars, mid-size SUVs and large pickups. The analysis considered factors affecting consumers (cost of technology and fuel, mobility and performance) as well as those affecting society (pollutants, greenhousegas emissions and “energy security costs,” that is, dependence on oil from unstable foreign sources).

Advanced diesel technology (such as that used in the Mercedes E320) yielded the biggest savings to consumers, especially over the life of larger vehicles:  $460 for the car, $1,249 for the SUV and $2,289 for the pickup. The hybrid engine did well, too, saving $198 over the life of the car, $1,066 over the life of the SUV and $505 over the life of the pickup. A mixture of 85 percent ethanol and 15 percent gasoline (commonly known as E85) actually resulted in a net loss of more than $1,000 in all three vehicles, largely because of the high costs of producing the fuel.

“Hybrid and diesel technologies are close,” says John Graham of the Pardee Rand Graduate School, the study’s senior author. “But diesels have the advantage for the typical motorist and provide a strong edge for drivers who require towing, hauling and rugged capabilities such as those offered in pickups. Hybrids have a competitive edge for urban consumers who experience more stop-and-go city traffic.” 

Graham also notes that hybrids’ savings could equal or exceed those of diesels if the cost of hybrid technology falls significantly in the future.