Al,

The late 70s and early 80's MB diesels were designed to run on diesel fuel with a minimum cetane of 45.

Diesel fuel cetane ratings in America has steadily decreased from nearly 50 in the 60s, to 45 in the 70's and early 80's to around 40 or 41 common today. This is really too low for our diesels.

Adding cetane boosters can improve how smoothly the engine runs, and, by some accounts, can improve fuel economy to such a point that the additive pays for itself twice over.

Either way, if you do add something to the fuel, make sure it's a legitimate diesel fuel additive. Don't add anything like motor oil, or transmission fluid, and never try to burn up that used motor oil in your tank. Big Bad MOJO.

240Joe