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IWEMA enterprise is proud to introduce the latest development in LPG technology:   The D.F.D.
(Dual Fuel Diesel / LPG) system.

We succeeded to get  diesels running on a mixture of diesel and LPG.
The reason to develop this system was a request for more environmental friendly diesel engines. We achieved to combust virtually all polluting diesel particles, low Co and HC readings. Normal Diesel engines are able to combust only 75% up to 80% of the injected diesel. After installing the Iwema D.F.D. (Dual Fuel Diesel/LPG) system up to 95% of the injected diesel can be combusted. Normal MOT results for particles are between 2.5 and 2.0 M. After conversion 0.25 M is possible.

The amount of injected LPG  changes according to the engine limitations and the driving style.
If the system is tuned for the lowest total fuel consumption the amount of LPG is between 5% and 10%. This can result in a drop in fuel consumption up to 20% and a power increase up to 10%.
When the system is tuned for the highest performance the amount of  LPG can be over 30%  and a power increase of over 25%. 

Technical specifications of the Diesel / LPG system:

Max.engine power  (according to the system) : 1000 bhp
Venturi diameter : upto 65 mm
Min. amount of LPG  : 5% - 10%
Max. amount of LPG  : 25% - 35%        
Co. (possible) : 0.01%             legal: 0.50
HC. (possible) : 27 ppm          legal:  150
Particles (possible) : 0.25                legal: 2.50

The D.F.D. (Dual Fuel Diesel/LPG) system can be installed in all cars with diesel engines; Turbo, NON-Turbo (with and without throttle valve).
On this photo you can see a D.F.D.-system installed on our Land Rover Discovery 200 TDI.
The car always uses diesel and LPG.
The diesel will start the combustion of the mixture. The amount of LPG varies. On idle there is only a little amount of LPG in the combustion chamber and at partial  or full load  there can be upto 45% LPG compared with the injected diesel in the combustion chamber.

The LPG tank can be installed in or under the car, depending on the car and the size of the tank.
We recommend a LPG tank up to half the size of the diesel tank.
For most cars a 35 litres tank will be fine. This can result in an additional  radius of range  up to 75% compared with driving on diesel only.
If the car runs out of LPG it will loose its additional power but will keep on running as before the conversion.
The power will be according to the manufacturers specifications.


IWEMA enterprise  succeeded to get  a D.F.D. (Dual Fuel Diesel/LPG) system installed in this Range Rover 2.5 diesel.
The car was already highly tuned by Jeremy Fearn.
The conversion of the car gave the engine 200 bhp instead of the standard 136 bhp.
After the LPG conversion the engine became  approx. an additional 35 bhp. 


The engine with the 235 bhp was able to accellerate from 80 km/h (50 mph) to 130 km/h (81 mph) in less than 14 seconds in fourth gear.
The car was able to do the same test with 200 bhp in a little over 15 seconds.






The car has also been tested on fuel consumption on the road.
We drove the car for over 800 km (500 miles) on the motorway with a speed between 100 and 130 km/h (63 miles per hour and 81 miles per hour) and measured a fuel consumption of 1:10 (28mpg).

After installing the D.F.D. (Dual Fuel Diesel/LPG) system we got the following results: 

We drove a distance of 281 km (176 miles) on the motorway with a speed between 100 and 130 km/h (63 miles per hour and 81 miles per hour and had some trafic jam) and used 12.31 litres of diesel and 9.48 litres of LPG.(56.5% diesel and 43,5% LPG).
The result was a total fuel consumption of 1:12.9 km/l (36.3 mpg).

This 30% drop in fuel consumption and the lower cost of LPG makes the cost of motoring drop by approx. 46%.

The LPG tank we installed in the spare wheel arch is 75 litres. Therefore the car is now able to drive 2283 km (1427 miles ) between tank stops.


IWEMA Enterprise will start  installing a limited number of systems for a field test  in May 2001. If the test results are positive we hope to supply the system  at the end of this year or at the beginning of 2002.

This D.F.D. system is not a DIY system!

LPG installers for petrol engines are not capable of tuning a D.F.D. LPG system without a proper training.
Therefore we will not supply systems to installers before they are properly trained.

All given information can be different according to the type of diesel engine, set up of the system and the driving style.

The DFD LPG system is functioning marvelous and therefore we intended years ago to start supplying the system.
Unfortunately we aren't able to supply because of legal reasons.

At this moment you are not allowed to install and use any diesel LPG system in most of the European countries.

Therefore we can't offer this system.