Nearly 90% of new 2018 model year (MY) vehicles are explicitly approved by the manufacturer to use 15% ethanol blends (E15), according to the results of an annual analysis of warranty statements and owner’s manuals conducted by the Renewable Fuels Association (RFA), a trade association representing the ethanol industry based in Washington, D.C..

That is up from last year when approximately 81% of MY2017 vehicles were formally approved by automakers to use E15, the association said.

“Automaker acceptance and approval of E15 continues to expand rapidly, and almost all new 2018 vehicles carry the manufacturers’ explicit allowance to use this lower-cost, cleaner-burning, higher octane fuel,” said RFA President and CEO Bob Dinneen.

E15 has been experiencing incredible growth in the marketplace. Today, it is sold in more than 1,000 retail stations in 29 U.S. states.

For the first time, Japanese carmaker Nissan Motor Company has warrantied the use of E15 in most of its MY 2018 vehicles, joining the majority of its competitors. Together, Infiniti and Nissan represent slightly more than 9% of the U.S. light-duty automobile market. Language allowing the use of E15 appears in the owner’s manuals for popular Nissan models, including the Altima, Maxima, Pathfinder, Rogue and Sentra, as well as Infiniti’s QX60, Q60, Q70 and certain Q50 models.

Other key points from RFA’s analysis include:

• The Detroit Three (Chrysler, General Motors and Ford), which collectively represent 44% of U.S. market share, all continue to clearly allow E15 in their vehicles. GM started approving the use of E15 with its MY 2012 vehicles, while Ford joined the following year and Chrysler began E15 approval with its MY 2016 vehicles.

• Other large automakers explicitly offering E15 approval for MY 2018 vehicles include Japan’s Toyota and Honda and South Korea’s Hyundai/Kia. Altogether, auto manufacturers with 89.4% of 2017 U.S. market share now approve the use of E15 in their MY 2018 vehicles.

• Subaru, Daimler (maker of Mercedes-Benz), and Mazda remain the largest vehicle manufacturers that still exclude E15 from owner’s manual fuel recommendations and warranty statements, together representing about 7.5% of U.S. market share. Mercedes-Benz, however, offers three of its most popular models as flex-fuel vehicles (FFVs) capable of operating on up to 85% ethanol.

• With 1.7% of the U.S. market, BMW also continues to exclude E15 from its fuel recommendations. However, BMW Group’s Mini vehicles allow the use of up to 25% ethanol blends.

In 2012, EPA approved the use of E15 in vehicles built in MY 2001 or later. However, auto manufacturers did not retroactively endorse the use of E15 in legacy vehicles that were already on the road. Since 2012, however, the number of major automakers approving the use of E15 has grown from one to 10.

RFA estimates that approximately 34% of the estimated 235 million cars, trucks and SUVs on U.S. roads today are approved by automakers to use E15 (including FFVs). Meanwhile, more than 90% of vehicles on the road were built in 2001 or later, meaning they are legally approved by the EPA to use E15.