Fuel economy for new vehicles sold in October averaged 25.3 mpg, which is the same fuel economy for light-duty vehicle sold in September, according to a study from the University of Michigan’s Transportation Research Institute (UMTRI).

Fuel economy ratings remained flat due to lower demand for fuel-efficient vehicles because of cheaper gasoline and improved fuel economy of 2015 model year vehicles compared to 2014 models, according to Michael Sivak, director of sustainable worldwide transportation at the institute.

The fuel economy ratings on new cars have increased by 5.2 mpg since 2007 when they first started being measured.

The data is based on the average sales-weighted fuel economy rating printed on a new car’s window sticker and is compiled by Sivak and Brandon Schoettle at the institute.

The University of Michigan also estimates the average monthly emissions of greenhouse gases created by a U.S. driver in its Eco-Driving Index (EDI), which uses vehicle fuel economy and distance driven to determine these figures.

EDI found that the average new vehicle driver produced 24 percent less emissions in this past August than in October 2007.