Ryan - call bp , they are more than happy to tell you all about supreme and where to find it. It's worth the few minutes, believe me.
Gary, you're right about most 'premium' diesel. Actually they are supposed to meet 2 of 5 standards to qualify. This type of 'premium' is just regular #2 with additives. Most of the time, these are added at the terminal. These are a little better than regular #2, however if the price is significantly higher, it's probably smarter to just use your own additives. The local sunoco even lists right on their pump Premium Diesel - with big check marks next to Injector Cleanliness and Thermal stability - detergent and antigel/stabilizer. In any case, Supreme and Premier are totally different than this type of fuel. A few other smaller companies do make their own true premium diesels, but they aren't widely distributed typically.