I generally get three 5 gallon jugs of diesel at a time. And those last me quite a while. Like a month. I generally add the fuel additive that helps boost octane , lubes seals ect. Does most folks add anything in the summer? I have never added diesel to my tractor summer or winter without it and here in the northeast its a must for winter fuel. I forget the name of it but its a major brand you see at all parts stores.