LPG Conversion

[Sprite]

I've been meaning to do a bit of a write up on this for a while now, but I wanted to give a long term report... and then kind of forgot!

I know that for some people it wouldn't be a popular mod, and we all buy these cars for slightly different reasons. For me, this has made a fun car cheaper to run than a boring diesel, and has saved me a significant amount of money with only minor inconvenience. If anyone wants the full details I can bore them with the full spec, but in summary its a BRC kit with a 50l tank and hidden filler. I went for a premium kit and had a good chat with the installer before taking the plunge as I wanted to make sure it would be done exactly as I wanted. Normally I would have done work like this myself, but I needed the certificate for the insurance and didn't want the hassle of getting it inspected afterwards in order to get one.

I've done about 35k miles in it since the install and definitely have no regrets. I don't want this to come across as an advert, so if anyone has any questions, feel free to ask and I'll answer as best I can. Anyone who spoke to me at Zedfest last summer would have seen the install and how impressed I was with it. Anyway, here's some pics:





Advantages:
LPG is between 50p and 62p a litre at present (this is by far the biggest advantage for me as I do at least 20k miles a year in the zed)
Over 600 mile range with both tanks full (came in handy on a drive to Switzerland this spring when many of the fuel stations in France had sold out due to the stike)

Disadvantages:
Obvious loss of boot space,
LPG range just 260 miles, so requires more frequent fill ups,
Very slight hesitation if switching to LPG under wide open throttle if it hasn't been used for a while (due to the length of the injector lines)
Additional servicing of LPG filters
You can feel the weight of the liquid gas moving in the tank if it is half full and you are driving enthusiastically. This is because the tanks aren't baffled so it does slosh about a bit. A lot of my time is spent on motorways, so this isn't really an issue. I just make sure it is low or full (or empty and running of petrol) if I want to have some fun.
LPG cars aren't allowed on the channel tunnel at present (as of 2017) but most ferry operators seem to be OK with it.

Overall, I've seen a bit of a reduction in MPG when on the gas which was expected as the energy density of LPG is lower than that of petrol. However, since LPG has a higher octane rating than petrol it does mean that I get the full benefit of super unleaded when I switch back, rather than requiring the ECU to take time to re-adjust.

Cheers,

Dave

 

[Chris_D]

Really interesting sprite! Good writeup
Imo go bananas with posting the full specs and stats here as i'm currently looking for a coupe and am thinking about an lpg install.

 

[Fishy Dave]

Good write up, thank you. This caught my eye for the same reasons a couple of days back: http://www.ebay.co.uk/itm/vauxhall-monaro-6-0-vxr-with-lpg-12-months-mot-/162344616933?hash=item25cc7e43e5:g:k98AAOSw5cNYK1iB
8)

 

[mr wilks]

Certainly not the norm & made me "double take " when i realised at Zfest , glad you're still enjoying the 86 & that its still going well & iirc quite a high miler :?

 

[Machine monkey]

I was impressed when I had a look at this at zed fest very tidy

Like you say not the norm but if your enjoying your car for less £££ it's only a win win

 

[GMANLAW]

Interesting... I did a conversion on my previous car a "TT" as I was doing a lot of miles at the time. I did 50k trouble free miles with the BRC kit. When I sold the car I stripped the LPG kit out, returning the car to normal. Got a decent price for the kit and sold the car quite easily

 

[jabber]

What was the cost of the lpg install ?

 

[srhutch]

Presume that's the filler just inside the tailgate.

 

[Sprite]

Thanks everyone! I hoped that it might be interesting to some people. It took me ages to research all the pros and cons before taking the plunge with the conversion. There is a lot of good info out there but also a lot of "my mate down the pub once had one...." type anecdotes which were generally quite unhelpful.

Total cost of the conversion was £1750, which paid for itself in just over a year. I had originally hoped that it would payback in 10 months but the fuel economy on the LPG was worse than I had expected, so it took a bit longer. Aside from the odd day hooning around, I was averaging around 34mpg per tank on petrol (I occasionally got in excess of 40mpg when driving like a saint) This was calculated using the old school method of filling the tank to the brim and taking the litres to fill and the mileage each time, rather than using the dash readout. I was hoping for around 30mpg on the LPG, based on the data I could find online but in reality it is closer to an average of 28mpg. Still significantly cheaper than petrol, but does take longer to pay for itself.

I'm not sure how much practical boot space you would be left with in a roadster, but it does still leave you with quite a bit in a coupe as you can stack stuff above the tank and still have it covered with the load cover. The main thing you need to be careful with is the weight, as I think that the maximum load capacity is somewhere in the region of 50kg. With the LPG tank full, it would be near this limit with no luggage at all.... however, the BMW spec obviously allows for a full tank of petrol as well, which there would be no sense in carrying around with you. Personally, I tend to run around 10 liters of petrol in the tank for the start up (it starts on petrol and switches to LPG automatically as soon as it is warm enough) and then even with the LPG tank full, it still leaves me with most of that 50kg available for luggage. Unless you like carrying bags of cement around with you, its unlikely to be too much of an issue.

Interesting... I did a conversion on my previous car a "TT" as I was doing a lot of miles at the time. I did 50k trouble free miles with the BRC kit. When I sold the car I stripped the LPG kit out, returning the car to normal. Got a decent price for the kit and sold the car quite easily

This was my theory too, hence why I didn't want the bodywork cut in anyway for the filler. I also sourced a replacement ashtray, modified it with a part cover plate and had the switch/gauge fitted in there so that it is out of sight under the cover next to the cigarette lighter and can easily be returned to standard with no holes in the dash. At some time in the future I am going to relocate the fuel filler to behind the number plate. The current location which is next to the tailgate opening (well spotted srhutch!) works really well, however I've had a few instances when trying to fill up in France where they won't let me fill as the tailgate has to be open. They seem to be a lot more sensitive to having the boot open when filling over there, whereas its much more of a grey area over here.

You can save £10 each year on road tax by changing the tax category to alternative fuel, but you don't legally need to and it just didn't seem worth it as I'll need to have it inspected again when I remove the kit. If it had been a £50 a year saving, that might have been a different matter.

Since LPG is supposed to contain less contaminants than petrol, theoretically, the oil should be in better condition at each change. To be honest, I have't really noticed any difference as yet, but the engine had done over 100k miles when the kit was installed, so its likely to take a while to flush any of the old residue out. I also tend to run it on petrol if I take it on holiday as its easiest in Europe and does give you a tiny bit more power, so this also confuses things slightly.

To make a conversion worthwhile, you'd probably need to be doing at least 15k miles a year and intend to keep the car for around 3 years or more (based on it being a 3.0). I broke even on mine after at around 12 months but that's doing 25k miles a year of single cold start, long motorway journeys which are the ideal conditions for LPG. If your driving includes lots of cold start ups, you soon use up the petrol until it is warm each time, which eats into the savings. It's worth keeping in mind that the 12 months was just the point that I was no worse off for fitting the kit, and its only now that I am seeing the true savings (but they are great!)

Cheers,

 

[Chris_D]

Very interesting!
Thanks for your write-up. Food for thought for my own intended coupe purchase.
Thinking about alternating between keeping the roadster in the UK over the winters and the coupe over here in Holland then switching back to the roadster for the summers. Will be doing some stratospheric mileage throughout Europe from the end of January so this would make a lot of sense perhaps...

 

[gerryp]

I've noticed a couple of lpg coupes in the classifieds lately.

 

[Sprite]

Very interesting!
Thanks for your write-up. Food for thought for my own intended coupe purchase.
Thinking about alternating between keeping the roadster in the UK over the winters and the coupe over here in Holland then switching back to the roadster for the summers. Will be doing some stratospheric mileage throughout Europe from the end of January so this would make a lot of sense perhaps...

No problem! If you want to have a look at the install and can get to the North Wales or Nottinghamshire/Lincolnshire area, just drop me a PM and we can sort a mini-meet!

I'm not sure if you are aware, but only the UK and Holland use the same style of LPG filler. The rest of Europe use 2 different types depending on the country and Spain uses a different one entirely. The adapters are cheap enough to buy, but just a bit of a faff to use. Just make sure you go for a full size UK one when the kit is installed, rather than the small thread in ones that some places like to fit, that way you'll be sure that it can take the weight of the adapters and nozzle.

 

[Steve84N]

I do 20kpa but I wouldn't convert myself as the weight and loss of boot space are no good for the euro road trips we do. I consider 30mpg reasonable so petrol power for me.

 

[Chris_D]

Very interesting!
Thanks for your write-up. Food for thought for my own intended coupe purchase.
Thinking about alternating between keeping the roadster in the UK over the winters and the coupe over here in Holland then switching back to the roadster for the summers. Will be doing some stratospheric mileage throughout Europe from the end of January so this would make a lot of sense perhaps...

No problem! If you want to have a look at the install and can get to the North Wales or Nottinghamshire/Lincolnshire area, just drop me a PM and we can sort a mini-meet!

I'm not sure if you are aware, but only the UK and Holland use the same style of LPG filler. The rest of Europe use 2 different types depending on the country and Spain uses a different one entirely. The adapters are cheap enough to buy, but just a bit of a faff to use. Just make sure you go for a full size UK one when the kit is installed, rather than the small thread in ones that some places like to fit, that way you'll be sure that it can take the weight of the adapters and nozzle.

That's a very kind offer thanks, I might just take you up on that. Have a place in Liverpool so getting to N Wales would be easy. If I manage to source a coupe I'll deffo be in touch .
And re the adapters- had a friend who drove down to spain and didnt realise the difference in sizes and almost got stranded on the way running out of fuels. Got his pants pulled down at the garage he eventually found an adapter at. silly sausage.

 

[Petervaikimo]

I have had a conversion to LPG on one car so far, as it was a real gas guzzler, but I lived in Northern Scotland, so needed the Subaru Legacy 4WD. I had a donut tank in place of the spare wheel, which is slightly smaller than the unit you have.
I am currently in the throws of buying an elderly spritely gent of a car, namely the BMW Z4 2.5 manual Convertable.
I notice in your excellent article, that you have a coupe, which must have a. slightly larger boot than the convertible, but I was wondering if you have any knowledge of conversions for this type of car. I realise of course that I will not have any space left over, but I'll help the environment and my pocket book quite considerably.
I have studied the types of conversions and have decided on a Romano if it is possible.
Bests

 

[Chris_D]

Dave, it may also be prudent to suggest you add in your 'dis-benefit' list the fact that you're not allowed to use the channel tunnel if your motor has an LPG tank - maybe significant for those who do jaunts over to the continent from the south coast.
I think some ferry operators are a bit sniffy about LPG cars too.
Just a thought.

 

[Sprite]

I have had a conversion to LPG on one car so far, as it was a real gas guzzler, but I lived in Northern Scotland, so needed the Subaru Legacy 4WD. I had a donut tank in place of the spare wheel, which is slightly smaller than the unit you have.
I am currently in the throws of buying an elderly spritely gent of a car, namely the BMW Z4 2.5 manual Convertable.
I notice in your excellent article, that you have a coupe, which must have a. slightly larger boot than the convertible, but I was wondering if you have any knowledge of conversions for this type of car. I realise of course that I will not have any space left over, but I'll help the environment and my pocket book quite considerably.
I have studied the types of conversions and have decided on a Romano if it is possible.
Bests

I'm pretty sure that there is another guy on here who has an LPG conversion on a roadster. If you search LPG, it should bring up a few threads. If I recall correctly, the boot is the same size, you just don't have the space on top of the tank available in a roadster. Assuming you used a similar size tank to mine at the back of the boot, you'd still have space for a couple of holdalls or a reasonable amount of shopping etc.

Dave, it may also be prudent to suggest you add in your 'dis-benefit' list the fact that you're not allowed to use the channel tunnel if your motor has an LPG tank - maybe significant for those who do jaunts over to the continent from the south coast.
I think some ferry operators are a bit sniffy about LPG cars too.
Just a thought.

Good point - I've updated the original post. I've never had any issues with any of the ferry operators cross channel or to Ireland, although they do ask that it is switched off when driving on and off the boat for some reason. I think the fear on the tunnel is that it would vent for some reason, which although tremendously unlikely, I assume that they just don't want to take the risk. I've never found it an issue, but then I'm tight and tend to use the ferry!

 

[dhobbs]

Good read this. Any pictures of the interior modifications?

 

[benneyboy1]

Really good write up Sprite and I ma please to tell you you are not alone!!!!

I too have a dual fuel LGP conversion on my 2008 2.5Z4 which was done in 20011 by http://www.gas4cars.com/ when my mate previously owned the car and I have to say what a very professional job they made of it. It cost around £1700 for a 40 litre tank in the boot. The filler cap is very neatly installed in the bumper so no issues with open tailgates when refueling. The system is made by Prins who are based in The Netherlands. I will try and post some pictures when I get chance and once I work out how to upload them onto this site. I have a tiny (and I mean tiny) control module fitted on the dashboard just to the right of the steering wheel to switch the unit on or off and it also has 4 leds on indicating how full the tank is. I have not noticed and issues with weight when driving it and am quite impressed with how much room is left in the boot.

The joy of paying the lpg fuel bill each time I fill up never ceases to amaze me.

Chris D your more than welcome to have a look I can often be found in the Liverpool, Derby or Solihull areas .

Any questions just as and I will try ot answer them. :driving:

 

[Sprite]

Good read this. Any pictures of the interior modifications?

Not much in the way of interior mods I'm afraid, but that was kinda the idea Just an additional bracket built into the ashtray for the combined gauge/switch which is covered when the ashtray cover is closed:



Benneyboy - Good to know that there are few of us running on the cheap stuff! Sounds like your install is similar to mine. I'm also going to move my filler to the bumper (but hidden behind the number plate) to make it easier when filling up in mainland Europe.
:driving: