Barry:

The C number are the number of carbon atoms in the straight-chain linear hydrocarbons (paraffins) in the fuel.

Additives in diesel fuel? What additives? Diesel fuel in the US is basically just plain distillation range petroleum. Not much in the way of additives of any kind. The cetane rating is contolled by the exact distillation range from each source, not by additives. Cheapest stuff on the road. Too cheap in some ways, since it is fairly dirty compared to "synthetic" diesel fuel (also known as biodiesel). This is why it varies so much from station to station (or at least brand to brand).

Kerosene has more light chain hydrocabons (C8 to C16) than # 1 or # 2 diesel, and hence has lower energy content. Gasoline has only traces of anything larger than C10, and doesn't lubricate well enough, nor burn properly to use in a diesel.

Color and cloud point/pour point vary quite a bit -- back in the 70's I used to test diesel fuel Alcoa had stored for emergency use, and it was all #2 by label. Some had a pour point of 0 degrees F and some had a pour point of -30 degrees F. Rather wide specification range......

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!