That depends where you live. Some premium diesel is the real deal and offers better performance and running conditions, and some is garbage passed off as 'premium'. In Michigan though, and some midwestern states, true premium diesel fuels are available in some areas. Like BP diesel supreme or Amoco Premier. These two are both 50 cetane minimum, and have an awesome additive package. If you can get your hands on either of these fuels, it's worth whatever it costs.