I ran out of gas and stuck in 5 gallons of gas, why won't it start?

When you put in the gas was the 5 gallons fresh gas that you just got or was it something you had in a can for a long time ? Are you sure it was gas you put in and not maybe fuel that was mixed for a lawnmower or diesel for a generator? If it was clean fuel try cycling the key a few times before cranking the car over . Turn the key on till you hear the fuel pump run and shut off. Do this a few times This will prime the fuel rail. One last thing was the car out of gas for a long period of time . If so the fuel filter could have dried out and the dirt in the filter solidified completely blocking the filter . You may want to replace the filter . Hope this helps