dwa12479
.338 Win Mag
Are you talking E85 or regular unleaded thats 10%? 10% will last quite a bit longer than a few days.Make sure you rotate through those extra cans on a regular basis. Ethanol gas will go bad in a matter of days without stabilizer. Even with stabilizer I wouldn't store it for more than 30 days.
I keep 110 gallons in storage stabilized with a product from Castle called "Highway 95". Make fuel last for YEARS.