ANN ARBOR—A new national survey from the University of Michigan explores why consumers choose to drive SUVs, pick-ups, vans and minivans over cars, even though these so-called “light trucks” generally demonstrate lower fuel economy than passenger cars.

The U-M researchers say the increasing presence of light trucks on the nation’s roads is holding back fuel economy gains for light-duty vehicles, a category that encompasses passenger cars and the larger light trucks that many consumers drive on a daily basis. Fleet fuel economy for this category has increased very little in recent decades, from 19.6 miles per gallon in 1991 to 22.0 mpg in 2015.

While individual vehicle models tend to gradually get better gas mileage over time, the fleet fuel economy depends on the mix of cars and trucks being bought and sold each year in the U.S. This mix has fluctuated over the past decade, but light truck sales have increased in several recent years, especially when gas prices are low, the researchers say.

The federal Corporate Average Fuel Economy, or CAFE, standards—which President Trump plans to re-examine—currently set a target of 54.5 mpg for this fleet by 2025. That target, however, was based on forecasts that included a greater share of passenger vehicles by this point.

“The actual trend has been different from what was forecast, with shares of passenger cars staying relatively flat or even decreasing during some years,” said Brandon Schoettle, project manager at the U-M Transportation Research Institute and co-author of the new study. “The much discussed 54.5 mpg target is now no longer expected, due to the fact that the anticipated sales mix may eventually tilt toward light trucks in the coming years.”

Schoettle, and his colleague, UMTRI research professor Michael Sivak, surveyed 1,230 people in an effort to identify the lure of larger vehicles. Key findings include:

• 69 percent of light-truck owners said they use their vehicles primarily for general transportation; 65 percent said commuting; 17 percent said outdoor recreation and 13 percent general work (respondents could give multiple answers).
• In response to a question about the primary reason for owning a light truck, 19 percent said general utility; 14 percent said large family size; and 10 percent said moving cargo.
• More than one-third of both light-truck owners (36 percent) and passenger-car owners (37 percent) said they would not consider a vehicle type other than the one they’re currently driving.
• The main disadvantage listed for switching from a light truck to a passenger car was reduced cargo capacity (66 percent), followed by reduced hauling capacity (29 percent) and reduced safety (28 percent).
• Switching from a conventional light truck to a plug-in hybrid light truck raises the concern that requiring special equipment to charge the vehicle would be a major disadvantage (50% percent). Concern was also high regarding other disadvantages such as increased initial vehicle cost (46 percent) and limited or decreased driving range (43 percent). The concerns regarding the disadvantages of all-electric light trucks mirror the same items identified for plug-in hybrid light trucks.

The survey, “Consumer Preferences and Motivations for Owning Light Trucks versus Passenger Cars,” was supported by an unrestricted gift from ExxonMobil Corporation.

More information:

• Michael Sivak
• Brandon Schoettle
• UMTRI’s Sustainable Worldwide Transportation Program