Simplify the following text for a Grade 9 native English-speaking person.
Original: Nearly all the gasoline sold in the United States today is mixed with 10 percent ethanol , a mix known as E10 , and motor vehicle manufacturers already produce vehicles designed to run on much higher ethanol blends .
Simplified: Most cars on the road today in the U.S. can run on blends of up to 10 % ethanol , and motor vehicle manufacturers already produce vehicles designed to run on much higher ethanol blends .