cast: I located a fuel distribution company that has dyed diesel at the pump. One is a low speed pump, the other has a larger diameter nozzle which won't fit a can for high speed delivery.
I went in the office and got on a contract with them. Although I buy only 5 - 12 gallons of diesel every two or three months, they are happy to sell it. I use a plastic card to access the pump system and buy what I need and get billed on my credit card automatically. I save 40 - 50 cents per gallon.
I found them by calling around and asking smaller construction companies where they buy their off road fuel.
I know I don't save more thean $20 -$40 a year, but it's also the principle of the thing, paying road tax and sales tax on top of road tax for fuel I don't burn on the road.