What will happen to existing E20 vehicles when ethanol blending goes beyond 20%?

Vehicles designed for E20 may be able to safely use blends up to around E30 with conversion kits, but higher concentrations such as E85 will require flex-fuel vehicles. No universal aftermarket solution currently exists for all E20 vehicles, and any conversion would require validation for durability and emissions compliance. However, fuel additives can provide certain benefits, as per a report.