When EPA green - lighted E15 use, it knew
E15 vehicle testing was ongoing but decided not to wait for the results — most likely to raise the permissible concentration level of ethanol in fuels so that greater volumes could be used, as required by the Renewable Fuel Standard (RFS).
The larger point is that with thorough
testing — like those conducted by ORNL and CRC — we know that
E15 could be responsible for significant problems in
vehicles.