Preliminary results from the WardsAuto Fuel Economy Index show the average window-sticker MPG rating of light vehicles sold in the U.S. in 2017 was 25.5 mpg (9.2 L/100 km). A 0.5% improvement from 2016 falls in line with the small upticks recorded in the prior two years.
Low gas prices continue to be a primary factor in some consumers not opting for high-efficiency vehicles. The national average price of gasoline was $2.25 for the year, up 12% from 2016, but extends the sub-$3 rate to three consecutive years.
Standard gasoline-powered vehicles accounted for 93.9% of sales, down from 2016’s 95.1%. The index rating for these vehicles incrementally slipped from year-ago, from 24.5 mpg (9.6 L/100 km) to 24.4 mpg (9.6 L/100 km).
Share of battery-electrics and plug-in hybrids slightly increased to 0.6% and 0.5%, respectively. Hybrid sales share had slipped from 2015 to 2016, but reversed the trend in 2017, rising to 2.1%.
Light trucks hit a record-high 64.5% of indexed sales. The average rating was 22.6 mpg (10.4 L/100 km), a 2.4% improvement on prior-year. The primary body style was CUVs, accounting for 35.0% of LV registrations. CUVs also were the most improved light-truck segment on the index, up 3.4% to 25.2 mpg (9.3 L/100 km). Higher penetration of smaller engines and electrified powertrains is expected to continue large jumps in fuel economy.
The index results for cars rose 1.1%, at 30.5 mpg (7.7 L/100 km) for 2017. Large cars were the only segment to score lower than in 2016, but covered only 1.5% of the LV market. Luxury and midsize cars carried the group in terms of improvement, growing 1.9% and 1.4%, respectively.
Some automakers were able to achieve significant gains despite the overall subpar outcome. For example, Kia’s sales averaged 6.3% higher than prior-year, as the Niro hybrid accounted for 4.6% of the automaker’s sales in its first full year of availability. Share of all its electrified vehicles jumped from 1.2% in 2016 to 6.0% in 2017.
Mazda saw the sharpest downturn, slipping 4.7%. Share of its CUVs jumped, pulling away from small and midsize cars, which have higher fuel-economy ratings. Unlike most other automakers, Mazda lacks electrified powertrains that could counterbalance that effect.
The index results show a dampening of consumer interest in high-efficiency vehicles, but this does not necessarily mean automakers need to work harder to meet NHTSA and EPA fuel-economy regulations. CAFE mandates vary by automaker and are based on the size mix of vehicles sold each model year, so targets decline if there is a sway toward larger, generally less efficient body styles.