KEY 1. LPG fuel tank 2. Fill connection 3. Gauge and fuel switch 4. LPG electronic control unit 5. Gas/air mixer 6. Vaporiser (enlarged for visual) 7. Gas solenoid

Unlike a petrol vehicle, there is no spark in a diesel engine and the diesel is actually used to ignite the gas.

The system, in its entirety, is not complex. The LPG enters the engine along with the air and mixed before entering the intake manifold. With turbo and intercooled engines, a similar system is used, but in this case the gas is pushed into the engine at a slightly higher pressure than the intake manifold.

Advantages
Using LPG in your engine has a number of advantages. When the gas is in the engine, it has some very beneficial properties, as seen below:
1. Full burn of the diesel, as opposed to a normal engine only burning about 80%. As a result of this, there is no black smoke seen from the exhaust.
2. Emissions are reduced significantly.
3. An economic saving of up to 30% in fuel costs (some vehicles higher).
4. Due to the nature in which the gas burns, a slight power increase is also noticed, we try to keep this below 10% to eliminate engine/gearbox damage but much higher is possible if requested.
5. As proven with petrol / LPG engines, being a clean, total burn fuel, the LPG actually seems to clean the engine, thus prolonging it's life.

Fitting
The fitting of vehicles is quick a painless, taking a few days (including thorough testing).

The location of the tank is basically any space where it will fit. The tanks are smaller that for petrol conversions, due to the gas/diesel mix being about 20%. Our 7.5 ton DAF truck has a 60 ltr tank, which runs as long as the diesel tank (measures 315mm diameter by 800mm long).

Attached to the tank is a filler and then the pipe work to the front of the vehicle via a filter. The front end of the system is controlled via an electronic switch which houses the gauge so the level of gas in the tank can be seen in the cab.

The gas is controlled via a reducer that controls the amount of gas entering the engine and is heated via the water pipes in the vehicle.

On a turbo / intercooled vehicle, the pressure in the turbo is measured to obtain the entry pressure of the gas.

The final and most important part is the idle switch. Due to the way in which the gas bums in the engine, it is important (to avoid engine damage) that the gas is only used when the vehicle is running and not idling, so our system has a switch added to tell it when it is safe for the gas to enter the engine.

Ease of use
The system, once fitted, does not require anything to be adjusted or altered, although we recommend that after a few thousand miles it comes back to us to be checked (after bedding in period).

Emissions
The emissions from this system are much lower than other diesel engines and as a result, a converted vehicle may benefit from a reduced pollution certificate. This basically means that a vehicle polluting less is required to pay less road tax (£330 less over 3500kg). This depends on the type of vehicle converted and its use.

Safety
The system has many safety measures built in. In the event of a gas line failing, there is an electronic shut off built into the tank so that it cannot leak. There are also two shutoffs in the engine bay. Also, most vehicles incorporate a tilt sensor so if the vehicle is rolled, then the gas is shut off. The system is set up so that if there is a gas problem then the vehicle will run on diesel as before the conversion.

The tanks are made of 3.5mm steel and tested to very high specifications and can withstand major impact..

Engine Wear
The way that the gas gives a total burn in the engine means that rather that making the engine worse, it actually improves it, so that it appears cleaner if stripped down.

Reliability
The system is very reliable and to date we have not had a single failure. But should it fail, the built in safety devices will shut the gas down. The way the system is set up means that if the vehicle has no gas then it will run as it did before conversion.

Cost and availability of LPG
LPG at present costs around 50p per litre retail or less if you have your own tank installed at your business. There are over 1400 filling stations nationally selling LPG (many motorway services also), and more opening.

Conversion cost
The cost of the conversions depends on the type of vehicle being fitted. We can convert cars, vans or trucks. For current prices or more information, click here to get a quote.