Hmmm I found this on STARGAS' website... diesel-lpg conversion.

http://stargasphil.com/stargas/diesel.htm

The D-GAS (Diesel Gas Auto System) has been designed and developed by D-Gas Pty Ltd. The system has been designed to reduce diesel exhaust emissions on turbo charged and naturally aspirated diesel engines by improving the diesel combustion making the engine more efficient and lowering exhaust emissions.

Added advantages:

Smoother and Quieter Engine;
Increase in Performance;
Increase in Engine Torque;
Decrease in Diesel consumption;
Reduced Carbon build up in the Engine and Exhaust system
which in turn reduces carbon in the engine oil;
Lower engine oil temperature;
May increase Engine Life.
Click on link for complete text: http://stargasphil.com/stargas/diesel.htm