If you put in 6 gallons, add another 6 gallons of filtered sump oil. It will run well and not smell like it is burning engine oil.
Or, add 6 gallons of filtered vegetable oil. It will smell much nicerthan petroleum diesel.
Just about anything will work - what you are trying to do, is to add enough "cetane" (compression ignition) to allow the engine to run with a uel which has a high "octane" (spark ignition)

Standard Disclaimer:-
If YOU decide to do something which the manufacturer of YOUR vehicle did not design it for, then YOU are solely responsible for YOUR actions, regardless of what you read or heard on this or any other source of information.

In short - if YOU stuff up, YOU wear it.

__________________
Tony from West Oz.
Fatmobile 3 84 300D 295kkm Silver grey/Blue int. 2 tank WVO - Recipient of TurboDesel engine.
Josephine '82 300D 390kkm White/Palamino int.
Elizabeth '81 280E, sporting a '79 300D engine.
Lucille '87 W124 300D non-turbo 6 cylinder OM603, Pearl Grey with light grey interior


Various parts cars including 280E, 230C & 300D in various states of disassembly.