This page will document the conversion of our Citroen HY Van to LPG by Flintshire AutoGas :

Established in 2003, Flintshire Autogas specialise in converting petrol driven vehicles to run on LPG and are installers for most major LPG equipment manufacturers. With 30 years’ experience in the motor trade, they have converted approximately 700 vehicles for various clients including the local authorities and major car manufacturers.
Having converted so many vehicles, we think our Citroen HY is in very experienced hands.


Old technology LPG conversions would traditionally result in slightly less power when running on gas, yet LPG has a higher Octane rating (see  than Petrol, so has the potential to be MORE powerful.

This very high octane rating (higher than racing fuel) can be exploited to give more power and better fuel economy when using LPG by advancing the ignition curve. However, the switch back to petrol would result in the engine  'pinking'/'knocking', poor running and potential damage.

Flintshire Autogas get around this by fitting a new Electronic Distributor that has 2 ignition curves, one optimised for LPG, and the standard one for petrol. When running on LPG the more advanced ignition curve is automatically selected.

Standard LPG conversions generally save around 40% over petrol, this special Flintshire AutoGas Citroen HY advanced set up results in LPG use being more powerful and savings rise to better than 50%. Just 70p a litre instead of £1.38. This conversion should give the equivalent of over 45mpg on a long run as well as better performance.

A LPG converted engine runs cleaner, contaminating the Engine Oil far less than a petrol equivalent giving longer engine life, but more importantly longer Oil life. A Citroen HY does not have an oil filter to clean the Oil, making this a major benefit. Engine Oil life will increase from 3,000miles to about 9,000miles resulting in typical annual servicing savings of up to £200. In addition to this the lack of a convential distributor means there are no time consuming points to replace/set up along with alterations to the ignition timing every 6,000 saving a further £45 a service(one hour labour + £15 for points/condensor).

The Flintshire Autogas LPG conversion will save more than £500 over 3 years on servicing cost alone. The Flintshire Autogas calculator  shows how much money you save on fuel in addition to the other savings. 


A Citroen HY will be cleaner and quieter on gas, longer lasting, less polluting by about 20%, Congestion Charge exempt, have a lower Road Tax rating, save better than 50% fuel, drive smoother and climb hills better. Not to mention reduced servicing costs. We think our LPG conversion cost will be recouped in less than 9,000 miles.


The link below documents a real world conversion on an old vehicle with benefits that you don't normally hear about, smoother running, better driveability with less engine wear. Note that the LPG conversion in the link was not done by Flintshire AutoGas and does not use the Dual ignition curve proposed her. 



 For our business we will need a 240v mains capability when out at shows, something like a portable generator. A friend has converted one to run on LPG.

We have seen it and the generator is so much quieter with a much more pleasant exhaust smell that we intend to have an external gas connector on the Citroen HY van so that our generator can hook into the main LPG tank in the van and run from that. A LPG generator should have roughly half the running costs of a petrol equivalent.


So enough of why we should do it, let's get it done then publish the results to help others decide about the value of LPG.