Despite the fact that Hyundai and Kia had to roll back their mileage claims, the typical new vehicle sold in the US is getting record mileage.

The average fuel economy of all new vehicles sold in the United States remains at its highest level ever, while emissions are at a record low, according to the University of Michigan Transportation Research Institute.

The average fuel economy or window-sticker values of cars, light trucks, minivans and sport utility vehicles purchased in November was 24.1 mpg, a full mile per gallon better than a year ago. The figure was the same as in October but up from 23.8 in September.

The average improved despite the fact that two of the brands that have led in the improvement of fuel efficiency, Hyundai and Kia, have had to scale back their mileage claims, following an audit by the Environmental Protection Agency. The government agency, which overseas vehicle mileage standards, found both companies had flubbed standard procedures while performing the mileage tests for the government.

(Hyundai/Kia facing possible Senate investigation over mileage mess, Click Here.)

UMTRI researchers Michael Sivak and Brandon Schoettle said the record-tying mark also represented a 20% increase of 4.0 miles per gallon from October 2007, the first month of monitoring by UMTRI . The improvement in fuel economy over the last five years corresponds to a 17% reduction in fuel consumption per mile.

In addition to average fuel economy, Sivak and Schoettle issued their monthly update of their national Eco-Driving Index, which estimates the average monthly emissions generated by an individual U.S. driver. The EDI takes into account both vehicle fuel economy and distance driven—the latter relying on data that are published with a two-month lag.

During September, the EDI dipped to a record 0.80, down from 0.81 in both August and July and down from 0.86 a year ago (the lower the value, the better). The index currently shows that emissions of greenhouse gases per driver of newly purchased vehicles are down 20%, overall, since October 2007.

Automakers anticipate still further mileage improvements in the coming years. The industry has to meet the government’s new 35.5 mpg Corporate Average Fuel Economy, or CAFE, standard by 2016, and a further increase to 54.5 mpg by 2025.

Actual vehicle mileage will come in lower, however, reflecting credits and other factors that manufacturers can earn.

Meanwhile, federal regulators plan to conduct an extensive review of technologies designed to improve mileage. The so-called mid-term report, due out in 2015, will look at factors such as cost, effectiveness, ease of implementation and consumer acceptance.