FREQUENTLY ASKED QUESTIONS
What is LPG?
LPG is the abbreviation for Liquefied Petroleum Gas.
Where is it from?
40% of LPG comes from the refining of crude oil and 60%
straight from field production. At atmospheric pressure
it is a vapour, under moderate pressure it becomes a liquid.
How is it Stored?
The liquid gas is stored in pressure vessels which are constructed
to BS5500. The manufacturer issues a test certificate, together
with a letter of fit for purpose, in accordance with pressure
Where is my nearest filling point?
For your nearest point go to our link at the bottom of the
Does LPG damage my engine?
No. LPG is a clean burn fuel which extends engine life.
What about my vehicle's performance?
LPG does not show any appreciable difference in performance
to other fuels, however it does run quieter than diesel
due to the absence of knocking effect.
How big is the tank?
A tank smaller than a spare wheel will give an average range
of 300 miles. But remember you will still have the petrol
What can I save?
Taking into account the cost of the conversion an average
fleet van traveling 30,000 miles per year could save £2,376.
Can I still use petrol?
Yes, the dual fuel capability of the conversion will double
your range. All kits offer the ability to change over the
fuel type on the go.
What would happen if I drove away with the fill
A breakaway coupling is fitted to the fill hose and when
broken will shut off the gas flow.
What would happen if I overfilled my tank?
Filling stops automatically at 80% capacity to ensure that
there is room for heat expansion. Any over pressure that
might occur would automatically vent to the atmosphere.
What would happen if someone left the vehicle unattended
The hose is fitted with a dead man's handle which must be
held to operate.
What would happen if my car caught fire?
If the fire was left then the petrol tank would explode.
However, due to the safety features of LPG installations
the gas in the tank would activate the pressure release
valve and the contents would vent in a controlled manner,
so the tank would not explode.
What if I was hit from behind?
All tanks are built to stringent standards, including impact
tests, and due to their nature are more robust than a standard
What would happen if I had a gas leak?
A small leak might be stopped by applying a wet towel with
protected (gloved) hands. Larger leaks would be detected
by the system and the gas excess flow valve would be activated,
shutting off the flow.
I have a classic car. When leaded petrol is phased
out will LPG be OK for my car?
Yes it will, but you would still have the same problems
with the engine that you would have converting to Unleaded
petrol. The valves, valve seats and possibly the head would
still need replacing with time.
Can my car be converted to run on gas?
For us to convert you car, it must have a petrol engine
to start with. Or diesel. Engine in excess or 2.5litres
with Turbocharger. There are some cars that we cannot do,
but the majority are OK.
Why is it so cheap?
In a word "TAX"! Currently Excise Duty on LPG
is 7.5p/ litre which is substantially less than petrol.
The reason it is so low is that the government have recognised
it as a greener fuel than petrol. How long it will stay
low is open to debate. I estimate / guess that we have a
minimum of another 8 years before they decide to put tax
up, assuming large numbers of people have conversions done
or buy pre-converted cars.
LPG is a by-product of the refining of crude oil and in
the past could be viewed being burnt off in flame stacks
at the refineries. This is another reason for the low price.
Will I still be able to use petrol?
Yes, all our conversions have a small dashboard switch that
easily allows you to change back should you wish.The switch
also incorporates a fuel gauge.
What are the down sides to having an LPG conversion?
i) The most common concern people have is that they will
loose their boot space to a LPG storage tank. We stock a
range of tanks which in an average family car leave in excess
of 50% of the boot space still free. For example an cylindrical
80 litre tank measures 900mm long by 360mm diameter. They
are always mounted horizontally, and usually against the
back of the rear seats between the wheel arches. We also
have available some do-nut shaped tanks to go in the spare
wheel recess to keep the boot space intact. It's worth remembering
that most people drive around with an empty boot most of
the time so are largely unaffected.
ii) Due to the slightly lower energy content of LPG a power
loss will be experienced. Typically this loss is minimal
and generally people are happy with the result. We also
have developed a performance gas manifold for minimizing
and in some cases eliminating these losses on particularly
large engines, such as big block American V8's. Should you
have any large or unusual engines to convert, please feel
free to call to discuss whether conversion is possible.
Can I do the conversion myself?
The short answer is no for safety reasons. We voluntarily
abide by LPGA regulations. They specify that an installer
of autogas equipment should be properly. We can provide
equipment to installers subject to proper training or full
LPGA approval. CORGI registration / approval carries no
weight here. Please call us should you wish to become an
installer. In certain instances single items can be supplied
to repair old conversions.
How safe are conversions?
When done properly in accordance with LPGA CoP11 gas conversions
are very safe. Obviously when carrying any fuel in a vehicle
there is risk involved, but in many respects LPG is far
safer than petrol. Most modern petrol tanks are made from
plastic which in the event of a fire or impact will melt
through quickly or break resulting in complete spillage.LPG
tanks are steel which makes them much more resistant to
impact damage and requires very high fire temperatures to
melt. They are also fitted with pressure relief valves to
protect against over pressure in the tank in the event of
a fire or other over-pressure situations. These valves are
designed to release some LPG to lower the tank pressure
in a controlled manner.
How much will it cost?
Central Garage (Carcroft) conversions typically range from
£1,000 to £1,400. It is rare that we charge
more than this for single point systems, but some vehicles
exceed these prices.
How many miles per gallon will my car do on gas?
On average 20% less MPG than on petrol. This figure is approximate.
Some cars do more, and some do less.
Is it worth converting my vehicle to run on LPG?
Environmentally, yes. The levels of exhaust emissions are
much lower than petrol or diesel vehicles.
Financially it makes sense. The current price per litre
for LPG is approximately 30 pence whilst unleaded petrol
is around 74 pence per litre.
Is LPG as safe as petrol for powering vehicles?
The carbon steel LPG tank is pressure tested to more than
30 bar and stores the gas at between 7 and 9 bar. No such
pressure testing is performed on standard petrol tanks.
Lovato equipment incorporates electronic, manual and hydrostatic
shut-off systems in case of failure. There are no systems
of this kind in use in the petrol system.
Which vehicles can be converted to run on LPG?
Most vehicles can be now be converted to LPG. Please call
us for a quote on your vehicle.
How many miles per gallon (mpg) can I expect running
There is a small reduction in the mpg for most vehicles.
For example, a vehicle with Multi Point Gas Injection doing
30 mpg on petrol would be expected to achieve approximately
27-28 mpg on LPG, however the current fuel price for LPG
is about 50% of the price of petrol.
What differences will I notice running my vehicle
Most drivers will notice no difference between petrol and
How do I know how much gas is left in the tank?
The system uses a switch for changing between petrol and
LPG. Incorporated in this switch is a series of LED indicators
which show the level of gas left in the tank.
How long will it take to convert my vehicle?
A standard conversion takes between 3 and 7 days.
Can I run my vehicle on LPG when I go abroad?
LPG powers far more vehicles on the continent than in the
UK. All the adapters needed to refuel are available from
Central Garage (Carcroft) for your conversion.
How long will it take for me running on LPG to
recoup the money I spent on the conversion?
Obviously as each vehicle is different it is virtually impossible
to answer this question generally. But you may wish to use
our calculator at the bottom of the page.
What about servicing?
Service after 1,000-2,000 miles on a while-you-wait basis.
We re-check all connections and ensure the engine tune is
still correct. We also recommend an annual LPG system service.
If your vehicle is going for routine maintenance the garage
can ignore the LPG system.
What about my insurance?
Your insurance company must be informed of the modification
to LPG although they generally do not charge any additional
premium. Our certificate of installation that the work is
to Code of Practice 11 is a guarantee of quality.
How long does conversion take?
Generally 3 - 7 days of workshop time with up to four weeks
advance notice depending on workshop loading.
Can you convert diesel cars?
Yes but the conversion works as a supplemented fueling system,
not a replacement as with a petrol engine.
Can I still run on petrol?
Yes, your vehicle is converted to dual fuel - petrol and
lpg. A switch is mounted on the dashboard enabling you to
select either fuel.
Does the vehicle have to be new?
No, providing the engine is in good condition we can convert
Where can I refuel?
A full list of LPG Refueling Stations is available on the
How safe are the tank and gas supply leads if
I have an accident?
In the event of an accident an excess flow valve will automatically
shut off the gas flow, also there is controlled cylinder
venting in case of fire.
What would happen if I accidentally added petrol
or diesel to the gas tank?
Petrol or diesel cannot be added by mistake because the
gas fuel nozzle only fits authorised LPG nozzles.
More practical user advice can be found in our knowledge
Find a Filling
Plan a Route
via Filling Stations
Return to LPG Introduction
For clear, no nonsense advice please speak to John at Central
TEL: 01302 722282