The average fuel economy for new vehicles sold last month dropped to 25.1 mpg, according to a new study conducted by Michael Sivak and Brandon Schoettle of the University of Michigan Transportation Research Institute.
The university attributed the lower average to the decrease in the price of gasoline. The average price of a gallon of regular unleaded gasoline nationwide dropped to $2.19 on Tuesday, which is down from $3.31 in 2014, according to AAA Daily Fuel Gauge Report.
The main reason gas prices continue to drop is due to the current cost of crude oil. AA said that the price of crude oil is falling below $50 per barrel for the first time since 2009, according to Edmunds.
Oil prices will likely continue to decline through the first half of this year.
Other factors include overseas political issues and the amount of oil being produced by higher-cost countries than the Unites States. Expect gas prices to start rising around 30-40 cents in the spring and summer.
The fuel economy average for the last month of 2014 represented a 0.2 mpg drop from November. The number is still a big improvement of 5.0 mpg from October 2007, when researchers first started collecting data on fuel economy.
Researchers also confirmed that the fuel economy of new vehicles sold rose in 2014 to approximately 25.4 mpg compared to 24.8 in 2013. This represents an increase of 0.6 mpg.
In order to reach its figures, UMTRI calculates average sales-weighted fuel economy from the monthly sales of light-duty vehicles (cars, SUVs, vans and pickups). They then combined city/highway fuel economy ratings that appear in the EPA Fuel Economy Guide and on window stickers found on vehicles.
The average emissions of greenhouse gases generated by the driver of a new light vehicle stayed put at 0.79. This means that average new-car drivers produced 21 percent lower emissions than in October 2007, according to the most recent UMTRI Eco-Driving Index.