In reply to cjrp (whom I can't reply to directly, strangely enough) -- it's harder to find diesel in the US than plain gasoline/petrol, but not that hard. Most trucks here use diesel, after all, and many gas stations have at least one diesel pump. It's mostly the gas stations along the commuter corridors to little bedroom communities which are gasoline-only.
truck pumps should not used to fuel cars, their flow rate is way to high and will cause damage if not bathe you in fuel. I haven't ever had an issue find low sulfur diesel on my travels, however I am mostly doing than East of the Mississippi.
Right about the truck pumps - I guess the main thing is that because trucks and other large diesel fuel consumers exist and are popular, the overall infrastructure for diesel, including refining and distribution networks, also exist. An individual pump is only a small part of that network.
