Hi, I'm cosidering taking the leap into the LPG world and I'm a complete novice in this field!! Thinking of converting my 1976 T2 1600 Viking conversion and I was wondering how much of a difference to fuel economy/running quality this will make? The bus is running a stock twin port engine with the only modification being an elec ignition. I would welcome your thoughts or experiences before I start getting quotes for a fit. Cheers Alex
Should half the cost per mile (approx) - If you can fit it yourself then cost might be around £300 or a pro job around £1000. Supposed to run as well on LPG and a little cleaner, no soot and carbon build up. When I find someone who can supply an air-cooled evaporator I may well take the plunge myself....
From my experience: Garages that stock it, have stock in, and whose pumps are working when you need the are not as prevalent than the pro LPG sites would have you believe. It's rare it's half the price of petrol. It drops your mpg i.e. if you get 25mpg on petrol you will not match it on LPG, it's lower. It can cause you engine temps to climb and can cause premature wear. Ford and Vauxhall both had off the shelf LPG ready cars that the took out of service very shortly never to come back, there are reasons for this. It's not maintenance free and needs certification and checking periodically after installation. Go in to this with your eyes open, my very expensive and fully compliant expertly fitted system ruined my car, though admittedly on older technology engines it seems to be better.
For many years I had an LPG Citroen Picasso, cost of fuel is about half and I had a contract with Countrywide which I paid monthly - their sites are quite common in the Midlands. On Unleaded it did an average of 35 on LPG about 26 but it was the old 8 valve engine It did run hotter on LPG It lost a fair bit of power on LPG Never needed certification at an MoT ...not sure I'd have another but it ran from 10k to almost 200k with no real issues Cheers B
The 2 customers I've had through with LPG say it's great. They don't notice any worse performance and it's cheap mpg. But they both bought buses with it fitted already so I guess it was win,win for them. You have to run the odd tank of petrol though to keep the engine "dirty" - that must hurt when you're used to the cheap LPG. lol The only thing the fitter has to do is be able to "display competence". Anyone can fit it - there is now certification. I looked into it because you have to disconnect the exhaust gas-heater part to get the engine out.
We've run lpg cars for the past 180,000 miles but decided against converting our 1979 a/c camper. Below are some notes I made a few years ago for info - hope it helps Original LPG thread, written in late 2005 ( as you can tell from the fuel prices !!! ) We looked into converting our 1989 Cavalier 1600 hatchback 4 years ago having driven it on unleaded petrol for the previous 6 months. During this time it returned an overall 42.6 mpg . I sourced a supplier for the kit who would also commission it and issue the safety certificate. Price breakdown Full standard kit…………………......£450 Upgrade to “doughnut” tank…...£100 Commissioning……………….....……..£50 TOTAL……………………………...........£600 I decided to fit the entire kit myself as an experiment and it took the best part of 3 days. Anyone who is reasonably adept at DIY and could, say, fit a central heating system should be able to do the job. But most suppliers will supply, fit, and commission for you and I’ve seen prices quoted from around £900+. They can usually be sourced fairly locally via Free-Ads papers. The system has been up and running for around 4 years and the vehicle has covered about 70,000 miles using LPG. Per gallon of LPG the vehicle has averaged 34mpg but the savings are from the reduced price of LPG at the pumps. I’ve not kept track of the relative prices of LPG and petrol over the last 4 years but at the time of writing LPG costs 29.9p ltr ( at Cribbs Causeway – North Bristol ) and unleaded petrol is about 90p ltr. With this price differential over the last 70000 miles ( which it has not been in practice ) we have so far saved around £4000 less the cost of installation. Put another way, for the price of a gallon of unleaded petrol (90p x 4.546 = £4-09) the vehicle will travel 90/29.9 x 34 miles = 102 miles on LPG. The system consists of the tank which sits in the spare wheel well and is fed through a filler which I’ve placed near the standard petrol filler. From the tank to the front of the vehicle is the gas pipe and 2 wires, one for the fuel “gauge” (inaccurate!) and the other for one of the systems 3 gas safety valves. Under the bonnet the pipe goes into a filter and then another valve and into the regulator. This regulator is a demand valve which supplies the engine at slightly below atmospheric pressure although it itself is supplied at about 8 bar. Incidentally the regulator was co-invented by Jacques Cousteau who went on to re-invent it for Scuba equipment! Because the gas on rapid expansion cools significantly, the regulator would rapidly ice up, so it must be heated. This is done by plumbing in the vehicle cooling system to warm the regulator. So far this description features components common to all conversions. Thereafter it depends on the existing petrol system. On the Cavalier there is a twin choke carburettor and the gas is brought to this by splitting the pipe from the regulator. Fitted between the carburettor and the air filter are the 2 gas mixers and they resemble a gas cooker ring with many small holes and the “ring” is inverted over the carburettor. These gas mixers are unique to the carburettor or air intake system but a vast range of such mixers is available to fit most vehicles. For fuel injected engines the gas is apparently fed into the air intake. LPG mixes immediately with air and there are no problems relating to worn injectors / carburettor valves. This additionally means that LPG delivers full power on start up. A dashboard switch controls the 3 gas valves and also a valve which stops petrol getting to the carburettor. The switch panel has a crude system of LEDs which displays the gas level from a float in the tank. It is a very inaccurate and we judge the remaining fuel by reference to the vehicles trip meter. General Points. 1. Safety. The tank is some 6mm thick, being necessary to contain the gas at around 8 bar and the entire system has many safety features. I would much rather have a crash in a LPG vehicle than in a standard petrol vehicle. 2. Insurance. With reference to the above point on safety, most insurers do not increase the premium but insist on seeing the safety certificate issued by the supplier / installer. 3. Tank. A standard cylindrical tank fits behind the rear seats and would be too intrusive to be even considered. A “doughnut” shaped tank is the answer which is secured in the spare wheel well. The spare wheel can then be placed elsewhere as convenient. 4. Power. The vehicle is definitely lower powered with the LPG supplying the engine, owing to its lower calorific value compared with petrol. If you wished to maintain the power of a 1600cc petrol engine, it would be best to start with a slightly larger engined donor vehicle. Personally I’ve little interest in the maximum power and the 1600 Cavalier is perfectly driveable. As a matter of interest, in the US, LPG engines have been extensively modified to maintain almost similar power outputs as with petrol (probably at considerable cost ! ) 5. Octane. LPG is rated at 105 RON which is much higher than even 4 star. This means the combustion is much slower than with petrol, apparently resulting in a smoother / quieter engine. But it’s not a difference I’ve noticed. Bearing in mind that this vehicle is one of the last where it is possible to manually alter the timing, I have significantly advanced it in accordance with this increase in octane. This might not be possible with a more modern vehicle with an ECU etc. But I understand there are various “black boxes” which are supplied with more modern dual fuel conversions to adjust the timing when on LPG. They also provide the different advance curve required for optimal LPG usage in a particular engine . 6. Starting on LPG. I’ve heard of conversions where the vehicle starts from cold on petrol and when the coolant reaches a certain temperature automatically switches to LPG. But this has been unnecessary in our installation, as the vehicle always starts from cold on LPG. It must depend on how quickly, on a cold start, the regulator is supplied with sufficiently warm coolant to prevent the LPG icing up . 7. Availability of LPG. Our 50ltr tank gives over 340 miles and larger tanks are available. There are over 1400 filling stations which supply LPG in the UK including an increasing number on motorways. There are lists on the web. Availability is not a problem. 8. Potential price hikes. LPG ( for vehicles ) is not tax-free but has a very low tax rate which is why it is so cheap. Cynics keep telling me that the government might suddenly tax the fuel to a point where it has no benefits, but there is a long term EU commitment to the low tax rate. This is a “green” issue – LPG exhaust emissions being much kinder to the environment than petrol exhaust emissions. Prices around Europe are not much different from the UK. 9. Running out of gas ! No problem. The system is “dual fuel” and at the flick of a dashboard switch the petrol kicks in. This is only occasionally needed as we rarely run out, but we keep a couple of gallons of petrol for peace of mind. 10. Diesels. Diesels can also be converted but it costs more. I can’t really see the point as petrol vehicles are generally cheaper to buy in the first place. 11. Engine wear. Because the exhaust gasses are less corrosive, exhaust systems will last much longer with LPG. This combined with the higher octane rating also means less engine wear. The cylinder compressions in the Cavalier have remained constant throughout the last 70000 miles. In the US ( where there is little fuel price advantage in using LPG ) and Australia, an increase in engine longevity is regarded as a major reason for converting to LPG. 12. Transferability. The Cavalier is coming to the end of its life and we are looking to replace it with a Vectra estate or similar. I intend to transfer the entire LPG system up to the regulator to the new vehicle and then fit new components to supply the fuel injection system. The Cavalier is our main mode of transport but we also have an air cooled VW camper which I’ve decided not to convert because a. The drop in power with LPG might be unacceptable on a 1½ ton vehicle with an engine producing just 50 bhp ! b. Being an air-cooled engine the regulator would have to be heated electrically or by ducting exhaust gas. Both of these methods are available as options from suppliers but it’s introducing complexity to a vehicle noted for its simplicity. c. The camper does a low annual mileage and the payback would be too long to be viable. d. It’s a classic vehicle which on principle should remain unmodified !
Interesting opposite experiences for some of us! I had the 3.0 litre 6 cylinder Peugeot 406 Coupe, it would do 120 ish in LPG, around 135 on petrol, donut tank in boot and a range if 160 miles per tank. LPG did seem to keep the oil cleaner, but the car ran less smoothly and stalled often despite many returns to the installer and other 'experts'. Conclusion is the engine was too modern for LPG system, multi point injection and latest brain inclusive. I think I'd ask this...if LPG cars are less hard on their engines and running cost is a core selling point for manufacturers, why do no manufacturers make one in this country? Why are no hybrids based on this technology - afterall, a bloke with decent spanner ing skills can install it at home.
Tank space and it'll be like diesel which used to be far cheaper than unleaded until it reached a critical mass. Look at it now! Once there are loads of LPG vehicles the price will rise to catch everyone out. The manufacturers know this'll happen and all their efforts will only benefit the suppliers and the tax man so they don't bother.
I am seriously considering this, I met a guy in Dubs at the castle & he had done it. He was very pleased and claimed to get a 60% saving in cost, he had a 1.6 TP engine in his late bay.
The bit I am unsure about is the vaporiser, The guy I spoke too had a coper pipe strapped to the exhaust, this was filled with water & connected to an expansion tank, the hot water run through the vaporiser to stop it freezing. Not sure how the water circulates though? ???
Wow, Thanks for all the replies...some mixed opinions out there. I would certainly give it a shot at fitting a kit myself...would pay for itself sooner I guess..... Hmm, I think if I found a reasonably priced kit Id go for it, concerned about the increase in temp though...
