<uk.rec.cars.misc>
<Steve Reeds>
<Fri, 11 Apr 2008 20:59:15 -0700>
<df587$480033b9$3ec35a9f$7208 (AT) news (DOT) chello.nl>

When i seen the subject - and for a moment - i thought the user was
going to say just drive your car half as often .


--
www.krustov.co.uk

On Sat, 12 Apr 2008 10:13:04 +0100, Krustov <me (AT) privacy (DOT) net> wrote:

The difference is that that would work.

--

Ian D

I saved 50% - LPG conversion

In article <ftvjb7$2di$1$8300dec7 (AT) news (DOT) demon.co.uk>, Martin says...
Come back in 12-18 months time when you've recouped it if HMRC haven't
upped the duty on LPG by then.


--
Conor

I only please one person per day. Today is not your day. Tomorrow isn't
looking good either. - Scott Adams

Conor wrote:


--
Pete M - OMF#9
Range Rover V8 Turbo
<space vacant>
"Professional Petrolhead"

Converted two years ago so I think I have recouped ages ago

I'm not convinced that they're going to hike up the duty on LPG much more
than it is at the moment, or people will simply switch back to diesel if
they want something cheap(ish) to run.

A few basic facts - let's say a diesel uses 35% less fuel than a broadly
similar powered petrol.

So for every 1 litre of petrol consumed, the diesel would use 0.65 litres.

Now, LPG has a calorific value of about 20% (depending on who you believe)
less per litre than petrol, meaning that you need 25% more LPG than petrol
for the same mileage. Ok, it's not quite that simple, as you can add a bit
to the petrol mpg figure to compare like with like, assuming the engine's
still relying on petrol to start, and then add on a small amount of petrol
per mile that's needed to start it, but I digress.....

So, for the same mileage, we're talking:

1 litre of petrol
or 0.65 litres of diesel
or 1.25 litres of LPG.

Meaning almost double the amount of LPG compared to diesel.

LPG is already half the price of diesel (has been for a while now), so
there's no massive cost saving compared to running on diesel - though there
is the benefit that the petrol engines that get converted to LPG generally
don't have potentially expensive stuff like commonrail injection pumps and
turbos to go wrong, like virtually all diesels do.

Now obviously there's the people that run the likes of V8 Rangies on LPG -
they run them because it's at least vaguely affordable to do this. I'd
wager that most of them wouldn't bother if the price of LPG was a lot closer
to that of petrol. They'd do the maths and work out that a pokey diesel
would cost them less to run. The main reason there are so many big engined
motors about with LPG is that a lot of big-ish engines (if we're talking no
more than 8 cylinders) are a lot more economical than people might think, so
running on LPG makes financial sense. If it was 40-50% dearer than it
currently is, it'd still be a reasonable amount cheaper than petrol, but
diesels would still have the edge, cost-wise, even at the 120p/litre it's
approaching in most places, and IMHO a lot of the V8 LPG brigade would
switch to diesels. Even the kengestion charge is catching onto the fact
that loads of people are going about in LPG-powered gas-guzzlers and are
changing the rules (I've heard - I'm not 100% sure exactly what's
happening - haven't had the need to drive into central London, certainly not
at peak times, in bloody ages).

So, in short, LPG is still just about viable, but comparing it to diesel as
a "cheap motoring" option, it can't go up much more in price, relative to
diesel, or people would just start to vote with their feet and not bother
with it.

--
"For want of the price of tea and a slice, the old man died."

More like 10% anyway the Diesel equivalent of mine is 2/3rds the power and
not twice as economical.

I think Petrol is about 90% of Diesel, and LPG about 90% of Petrol, energy
per litre