As I understand it LPG is about half the cost of petrol but does only about 20% less mpg?

So it’s a no-brainer, right?

Of course there are issues with LPG supply in some places but if you can take normal petrol as well if you have to then no problem.

For example I’ve been thinking about a factory fit bi-fuel mk1 focus as my commuter chariot… what’s the catch?

Get a car with the installation already in and the paperwork in order.

Of course there are issues with LPG supply in some places but if you can take normal petrol as well if you have to then no problem.

I didn’t realise they could do that, you must loose a lot of boot space if you have two tanks, one for the gas and one for the petrol.

yes they usually use the spare wheel space for gas tank or you have a desifnated tank in boot reducing size etc

And gas burns ‘dry’ so you need to use petrol/diesel to start it up and for the first few miles, then again for a few miles every 100 or so.

Widely used in Oz where my Falcon had a conversion.

I have one here in italy. Aside from the spare wheel in the trunk, the main disadvantage is that most subterrenaean garages don’t let you park below the -1 level. That’s because the gas is heavier than air, and very explosive. My conversion, after about 8 years, is all clogged up with dirt and doesn’t work very well. If you get an aftermarket one installed, which it doesn’t sound like you’re considering, it invalidates the car manufacturer’s warranty on some bits of the engine. Even if it’s installed by a dealer. In all, with the kind of mileage i do (25k km) the economcs work out pretty much the same as an efficient diesel (at italian prices), which is what i’ll be buying next.

you cant use eurotunnel with LPG.

And gas burns ‘dry’ so you need to use petrol/diesel to start it up and for the first few miles, then again for a few miles every 100 or so.

Nah you don’t, not with a decent installation on a new-ish engine. Generally they start on petrol as the vapouriser freezes if it doesnt have warm coolant supply, but that can be avoided and they can start on LPG no problemmo. Most modern cars have hardened valve seats and don’t require the liquid lube anyway – it’s gone after a few cycles, running it every few hundred miles wouldn’t do any good anyway!

And on a real injection conversion, aftermarket, we’ve seen only ~10% drop in economy over petrol.

Would love to get 2 litre petrol MPV converted, 28mpg isn’t good!

However, it’s got 80k on the clock. I’ve worked out the payback period and it would have to last until 125k (at current fuel prices) to get back the installation cost.

Duel fuel is the way to go though, Highlands/Snowdonia etc there can be no LPG for miles, so nice to have the petrol tank still there. I’d be prepared to sacrifice the spare wheel for a doughnut tank and hope for the best with one of those sealent cans and breakdown membership.

…does only about 20% less mpg

I’d say that’s a worst case figure. 10% would be more typical.

And gas burns ‘dry’ so you need to use petrol/diesel to start it up and for the first few miles, then again for a few miles every 100 or so.

It’s not the gas burning dry that’s a problem, it’s the petrol pipes drying out and cracking if they don’t get petrol through them every now and then.
You don’t have to start on petrol, although most systems are set up so that they do to avoid the fuel pipe problem. A common set up is to switch to gas automatically when the revs reach 2000rpm with the throttle closed, ie. the first gear change.

Generally they start on petrol as the vapouriser freezes if it doesnt have warm coolant supply…

Not too much of a problem. I find that by the time I’ve negotiated the narrow lanes from home or the town centre traffic from work, it runs OK on the open road. On the rare occasions when I have started from cold and gone more or less straight on to a dual carriageway, it does hesitate a bit.

Most modern cars have hardened valve seats

As a general rule, if it’s suitable for unleaded, it’s OK for LPG.

i reckon i might get the missus car done. Will be going for an established kit instead of a cheap eastern euro one.

disadvantages are,
– it appears you have to maintain the kit a bit to keep it running well.
– no underground car parks or eurotunnel
– reduced boot space as i will not be going without a spare wheel.

I had calculated about a 2 year payback, not as quick as the adverts say but maybe more realistic.

Buying a car with it fitted, make sure it runs well on both fuels and you have all the info with the kit. might be worth taking it to a uklpg approved dealer for a check over.

It’s such a bull all this talk about the LPG being highly explosive. There was a research done a few years ago, I forgot by whom, showing it’s less likely the LPG tank would explode than a petrol one. They were shooting them with live ammunition IIRC. And no, it wasn’t “Brainiac” 🙂
BTW When my dad had his horrendous car accident he was driving his LPG-converted car. Despite his car getting written off there’s never been any fear of explosion.
The real issue is when you drive an LPG car in Europe you need converters as filling stations use different mounts in different countries. Otherwise it’s fine as long as you don’t expect to find LPG in Ireland.

The Eurotunnel issue is less to do with safety and more to do with bureaucracy; nobody has done the paperwork to put a tick in the box that it is OK thats all.
There are plenty of kits around, and some can be fitted by yourself. The theory that you need a certificate from the person who fitted it to show your insurer is not always the case (if at all the case).
Tinleytech
http://www.tinleytech.co.uk/
can supply kits for a fraction of the cost from other suppliers, and they are just as up to date technically as any of the others.
There are lots of kits / companies:
http://www.nicholsonmclaren.com/
http://www.prinsautogasuk.co.uk/
etc
But there is not always somewhere near you that you can fill up with LPG; you sometimes end up going out of your way just to find somewhere to get LPG, planning your route etc is hastle. Or you maybe lucky enough to be close to a LPG station, but prices vary a lot.
A diesel car is less hastle. Plus there is the make your own diesel option; biodiesel, used cooking oil.

Been running my L200 Truck on LPG for six years now with no problems,the mpg difference is next to nothing around 5% i’d think.Oh and there are LPG finder apps for your phone to locate places to fill up if you are in unfamiliar territory!

…less likely the LPG tank would explode than a petrol one…

There’s a series of pictures on the web somewhere of a Range Rover that rolled while off roading.
There was a petrol leak and it caught fire.
The driver got out OK.
A few seconds later there was an explosion as the petrol tank went up.
A few minutes later, the heat of the fire expanded the LPG in the tank enough for it to pop the safety valve open.
The escaping jet of gas caught fire and burned in a relatively controlled manner in one area.

If you are in the Midlands, I recommend Countrywide LPG.
They’ve got self service LPG pumps, mostly on industrial estates, open 24/7 and they are cheaper than forecourt gas stations.
You get a key and a PIN number. Just fill up whenever you want and pay by direct debit every month.

http://www.guardian.co.uk/environment/2008/may/10/biofuels.alternativeenergy

From that Guardian Article

At 15p a litre, home-brew biodiesel is fuel of the future

Every few weeks Gordon Elliott drives 22 miles to the Hare and Hounds pub in Marple, Cheshire, collects a barrel of waste cooking oil from his stepdaughter and takes it back to his personal oil refinery in his garage in Leigh, near Bolton.

Looks like we’re all going to start eating a lot more chips if we’re going to have enough waste cooking oil to keep us all on the roads,

I can’t imagine it’ll be too long before LPG will be taxed more highly, so that might be worth bearing in mind.

People have bee telling me that since I converted my Land Rover 10 years ago.
It’s still less than half the price.

I can’t imagine it’ll be too long before LPG will be taxed more highly, so that might be worth bearing in mind.

sure i’ve heard it’s been frozen until 2014. could be wrong

I’m considering having my petrol t4 done. Quite a few people on the vwt4forum have had it done.

this is the cheapest place i’ve seen a conversion for

http://www.professautogas.co.uk/

2 ppl i know of have had it in 4 years with no problems

Just got my Countrywide bill for the month.
I’m paying 58.3975ppl.

That ‘professautogas’ looks good value.

So £1300 for my Beemer, hmm.
Current
12000m at 25mpg = 480 gal / 2180 lit @124ppl = £2702
LPG
12000 at 22.5mpg = 533 gal / 2421 lit @70ppl (my local) = £1695

So, payback under 18 months.

There’s a guy near me with an LPG Hummer. 😐