I’d check the owner’s manual, but I’d guess the 2013+ Viper is not a flex fuel capable vehicle. It’d need a sensor in the tank that could figure out what type of fuel was in there along with injectors and a fuel pump that could handle the increased fuel demand from running E85.
Assuming that you buy GOOD gas, like Chevron, Shell, Mobil, Sunoco, I just recommend that every 8-10 tanks of fuel you push a bottle of Fuel Injector Cleaner (like Techron, STP, etc) thru a full tank.