Stop in for a cup of coffee

Hey yall. WAYYYY off topic but yall are the most active forum Im on. Pops just bought a 3500 Savanna Van 6.0 L with flex fuel. Hes senior age...... you know..... same age as my dart. He doesnt get the memo that you can put regular unleaded 87 & E85 in the same tank. Anyone with common up to date knowledge knows that THATS the point of flex fuel:BangHead:. Someone help if anybody owns ANY type of flex fuel.
Urgent because he's a quarter on gas and stranded.:thankyou: