have been using LPG-powered cars since 2005. The reasons are
clear and we shall explain them again here as we have also done
so over in our LPG Cars
section. Liquid Petroleum Gas-powered cars yield annual CO2
savings of 16% over petrol whilst hydrocarbon (soot) emission
are down by 40%. The NOx emission savings are 80% whilst Carbon
Monoxide emission savings are 35%. So it is clean - very clean.
However, it is still using fossil fuels. Peak Gas is much
further off than Peak Oil and many pundits (ourselves included)
see Gas as the perfect "transition fuel". LPG is produced as a
by-product in both the extraction and refining stages of oil
production. In the past it has been considered waste and flared
off. It is particularly abundant in the North Sea's 'wet' crude
oil. Consequently the UK is Europe's largest producer, producing
6.4 million tonnes in 2001. Of this over 3 million tonnes were
exported. Only 50 thousand tonnes (7.75%) were used as Autogas.
The rest was used for domestic or agricultural heating or in
chemical or refinery operations. Liquefied Petroleum Gas (LPG)
is a mixture of Propane and Butane. When used as a Vehicle Fuel
it is often referred to as "Autogas".
vehicle that runs on BOTH Petrol and LPG is termed 'dual-fuel'.
It starts on Petrol until warm then automatically switches to
gas. With Mileage of about 7,000 per year the reduction in
annual fuel costs are around £1000 due to the lower Tax on LPG.
Installation costs (+ value added tax) were £2,200. Payback
period is 2 years. Some Cars qualify for a grant in the UK (as
well as exemption from Congestion charging) plus you also get a
reduction in your annual Car Tax. Annual Car Tax on the
"alternative fuel" Toyota Aygo in 2010 was just £15. The
Insurance premium is under £200 per year fully comprehensive.
The Toyota Aygo is rated at 108g/km CO2 but the LPG reduces this
to 92g/km. Hence the Aygo is cheap to run and yields extremely
low emissions. Not all Cars have as much space under the bonnet
as this small car. Hence, if you are considering a dual-fuel
installation make sure that you have a bit of space up front.
Having said this, the LPG equipment takes up very little space.
Most, if not all cars that currently use Petrol can be
will not invalidate your Warranty so you can still get your car
maintained at your local dealership. Autogas requires a
pressurised cylinder to hold a supply of LPG in addition to your
normal petrol tank. Here we see the boot with the tank in the
spare wheel well. There is space for a tank holding 30l gross
although you can only fill it up to about 27l. This will yield
up to an approx 240 miles of range. In July 2010 you could fill
the tank at a motorway service station for about £18. Choose a
far cheaper option such as a major Supermarket in the UK (Asda
is good) and this cost will drop to about £14 for a full tank.
This is really cheap motoring. THIS car obviously has no spare
so utilises a pressurised foam can for emergencies. The
positioning of the 'donut' tank in the spare wheel well leaves
the entire boot space free. Although the Toyota Aygo is a
micro-compact there is space in this boot for one large piece of
luggage and a laptop computer bag. The simple chemical make up
of autogas ensures that it is clean burning. The engine is
quieter and lives longer.
where do you fill the tank? It varies from fit to fit but most
cars simply have a filler cap co-located with the petrol cap.
This is not possible on all cars and on the Aygo we had it
discretely fitted under the rear bumper with all LPG piping
running under the car. The LPG flows into the tank via a small
hole in the middle of the spare wheel well. How do you know it
is full? Well the Autogas pump simply stops pumping - much as
with petrol. There is a small addition to your dashboard - a
small fuel gauge using small LED's. These are only a rough
indicator and drivers familiar with LPG keep an eye on mileage
as a better indicators of when to next fill up. This small
combined indicator and switch shows how full the gas tank is and
allows you to switch over to petrol manually. However, this is
rarely necessary. You treat your petrol tank as your "spare"
which can actually yield 400 miles of range if you leave it full
up. Of course you don't leave it full up as that means having to
haul around a tank of petrol all the time. So you only leave it
one-quarter full to get better performance.
So, consider the challenge: you have a Carbon-Neutral Home,
don't fly and consume the barest minimum. How do you get your
direct carbon footprint down to one tonne? With emissions of
just 92g/km and 1,000,000gm of carbon to play with gives you an
annual range of 10,870km or 6800 miles. Of course this is highly
simplistic but you can have low-carbon transport. To go any
lower you need to switch fuels and move over to electricity...
But that is another story.
So load your Aygo with four people and you get 23g/km/person.
Compare this to Full Transatlantic Cruise Ship = 1611, Short Haul Flying = 250 to 300, Long Haul Flying = 201, Motorbike = 107, Bus = 89
and Rail = 60. Some might argue with these numbers but the
ball-park figures speak volumes. Is it possible to drive a car
and look down upon public transport? Possibly, but that is not
the point of this exercise. There is no such thing as an
environmentally friendly car and their days are numbered. The
amount of metal and plastic per person is unacceptable in the
long term. Then there is all that road space and their wider
social impacts. Cars are not the spawn of the devil. Lots of
cars are. Car culture is. If you don't need a car don't have
one. We recognise that isn't quite yet possible for many of us.
If you must have one - choose wisely.