Should I be running the fleetguard winter fuel conditioner/addative they sell at Cummins dealers? They told me I don't need it because gas stations put it in there diesel fuel annyway? Isn't that different? How can I be sure gas stations are using a winter blend? Should I use it anaway (the fleetguard stuff)? Don't they have to (gas stations)? I live in South east Massachusets, its about 30 degres out right now (5:30 pm). Also what is that asphatelene conditioner by fleetguard? What does it do? Should I use that in the summer? What about cetane booster in a fuel addative? Is that important, or a waste of money $$$$? 
