To convert to LPG or not?

Meatball

Meatball

Meatball

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Joined
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St Albans
Hi,

The car: 2008 Honda Civic 1.8 (85,000 on the clock). Averages 45-50 according to computer.

Background: I purchased my first home earlier this year. My commute is now longer (90% motorway) with my estimated mileage around 15-16k.

My nearest garage (Shell) sells Autogas at 62p a litre (currently) which got me thinking about converting the Civic. I know of a UKLPG approved garage who have quoted £1,000 for the conversion.

Any advice? I’m attracted to the lower fuel costs and more ‘eco’ credentials of LPG, however I’m questioning whether it’s worth investing 1k in a car that is quite old, not worth much especially with the mileage I’ll be adding.

I’ve used an online calculation which says I could pay off the conversion in 10 months based on the following:
LPG conversion: £1,000
Currently weekly petrol cost: £55
Current Petrol cost: £1.25
Current LPG cost: 0.62

Weekly / monthly / yearly costs:
Petrol: 55 / 235 / 2867.86
LPG: 23.63 / 134.45 / 1635.81
Maximum yearly saving = 1232.05
 
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Diagro said:
You would use more LPG vs Petrol. Just so you know
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Yup, I have personal experience of this.

My girlfriend had a LPG-converted Suzuki Swift, and we planned to do a trip around the Baltics in it. At the end of the first day of the trip the LPG system broke and we had to do the rest of the trip on petrol.

We had worked out how much the trip would cost on LPG, and at the end the amount of petrol we used was within single digit pounds of what the estimated LPG amount was.

It's false economy. Don't do it. Your car will run like crap and you won't save a penny.
 
I can see no sensible reason to invest 50%+ of the value of your current car into making it LPG tbh.

It will add no value and just give something to go wrong with the car (not that civics are generally known for being unreliable) on top of general age related issues. If you can squeeze a genuine 45mpg+ out of a petrol car that is also reliable then continue doing so until it dies.

It's also worth checking the LPG usage as above
 
thewanted said:
Yup, I have personal experience of this.

My girlfriend had a LPG-converted Suzuki Swift, and we planned to do a trip around the Baltics in it. At the end of the first day of the trip the LPG system broke and we had to do the rest of the trip on petrol.

We had worked out how much the trip would cost on LPG, and at the end the amount of petrol we used was within single digit pounds of what the estimated LPG amount was.

It's false economy. Don't do it. Your car will run like crap and you won't save a penny.
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what an absolute load of crap!!

@Meatball FYI, older LPG systems weren't as efficient, so did tend to burn a fair bit more gas than petrol. Modern ones however have direct injection and much better management.
Mine does about 2-3 MPG less on LPG than it does on Petrol (22-24mpg vs 24-26mpg), running wise there is a slight bit more power on Petrol but you really don't notice it to be fair.

I would only advise doing this if you plan on keeping the car for a couple of years.
Also what was the make of the system you were quoted for ?
I was told BMC or Prins are the only ones you really want to be fitting.

I paid £2100 around 6 years ago for a BMC kit (V6 model so a little more complicated, hence the higher price for the kit)
Apart from servicing the system, it has had a repair once in that time, but other than that pretty much problem free, done around 120,000 miles on it by the way.
 
@MassiveJim was just about to say the same. I wouldn’t necessarily recommend LPG in the OP’s case, but the systems I’ve used have given virtually the same power and economy on LPG as on normal petrol.

A friend owns a transport company with a fleet of RAM 3.5t trucks with the Hemi engine, all on LPG. He swears by it and most of his fleet has over 400k on their original engines. They’re all running 5th generation BRC kits. I wouldn’t fit it to a complex turbo / supercharged engine like the one in my Range Rover, but on a basic N/A motor it seems like a good choice. I’ve been toying with the idea of buying an old Lincoln Town Car and getting it converted: would be a lot nicer than my current shed and a lot more economical too.
 
I had an LPG setup on my first P38 Range Rover. I cant imagine it was a terribly new system, but I liked it.

LPG costs roughly that of diesel (at least it did at the time). And I found that it was comparisons against diesel equivalents thay were the real comparisons to make. As if it was purely a pence per mile argument, it would be LPG vs Diesel realistically.

I ran my P38 (4.6 V8) mostly on LPG. Although you do start the car on petrol. On LPG though, I averaged 13.5 MPG. This rose to around 16-17 MPG. Not very much in number value, but still relatively significant as a percentage. I would factor in somewhere around the 10% mark in a drop in fuel economy. On top of that, remember, you do start the car on petrol until the system is all warmed up. So it's not like your not buying petrol. Although I did fill both tanks up once (100L LPG and 100L petrol), and it cost about £200 at the time. This was probably around the time when petrol was at its peak. Also worth noting, I never got more than 70L LPG in the 100L tank, due to gas expansion and stuff. So it pays to get as big a tank as you can.

I could get around 200 miles out of the tank usually. Which was fine most of the time, but I was regularly travelling to visit the wife's Gran as she wasnt well, and that was 130 miles away. So it was a touch awkward with having to basically fill the tank twice when we went to visit.

Overall though, at 13.5 MPG, and petrol half the price of diesel, I was basically getting the equivalent of diesel pence per mile running a V8. So these issues I didnt mind.

I'm not sure I could be bothered with the hassle in a car that already returns 45 mpg though. I mean, it makes sense in large capacity, thirsty engines. But in a car thay already returns 45, I dont think I'd even bother considering the switch to diesel. Let alone forking out for a quality LPG system.

As said above, you would need to keep the car for several years just to break even. And with the car being a bit older in the first place, is it really worth it? Are you likely to be wanting to change car anyway in 3 years time once you have broken even?

As I said, not against LPG. At all. Almost bought an already converted 4.2 A8 earlier this year. But that's the sort of car I'd consider it with.
 
LGP is dead in the water like it always has been? less and less garages selling it, i would not bother
 
I have noticed around my part of the world that most garages that used to sell it have stopped over the last couple of years. I'd be slightly wary of it because of that, also now electric cars are taking off they'll become the go to for green and cheap driving so might well leave LPG in limbo as it just never really took off in the UK.

For you though if you're getting 45mpg with your civic do you think you'd get another 3 or 4 years out of the car to make it worth while doing the conversion?
 
Considering the cost of conversion, the lost of space, and the inconvenience to sell later, and I wouldn't personally have a cilynder inside the car, would take few years to break even.
Even if costs are not great for your mileage, let's say you decide to go for a diesel, and put 2k+ and not sure how reliable the car is. How long would take to break even?
 
Thanks for taking the time to respond, it appears the general consensus is a resounding ‘No!’ which I suspected.

I plan on keeping the Civic for at least another couple of years before replacing it should nothing go horribly wrong. I’d love to replace it with an electric vehicle and have a driveway for the home point, but my savings have all but gone. I also feel it’s too early to go green with the cars costing quite a lot with a fairly limited range still. We’ve got an electric van at work and with a charge point so there’s potential I can use that in future.
 
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If you like the civic, why not look at switching to one of the diesel ones?

I've a golf gti as I only do about 40-50 miles a day, any more I'd look at getting a diesel golf. My average MPG would go from 30 to about 70.
 
If he's already getting between 45-50mpg it's really not worth going diesel as he's gaining only a few MPG more. The £ difference between 50 and 60mpg is pretty small.
 
AHarvey said:
If you like the civic, why not look at switching to one of the diesel ones?
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Whilst the Honda Diesels (2.2) are decent enough - the cost to switch (or even potential cost to switch - e.g. fault with new car), will wipe out any savings made around 15k annual mileage. If he was doing 20k+ then it would more likely be worth it.
 
totally unrelated to the original post but we have looked at fitting lpg to some our diesels,

slightly different way of operating on the diesels in that it runs a mix of diesel and lpg rather than switching completely tends to give decent improvements in emissions and about a 25% fuel cost saving overall, and err a small performance gain :) :) :)

but complicated completely unheard of by most people and very few places convert smaller diesels. quite fancy getting one of the taxis done as a trial
 
AHarvey said:
If you like the civic, why not look at switching to one of the diesel ones?

I've a golf gti as I only do about 40-50 miles a day, any more I'd look at getting a diesel golf. My average MPG would go from 30 to about 70.
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Can't imagine if your averaging 30 in a GTI you would average 70 in the diesel. I averaged about 30 mpg in my ED30, and my 1.5 TDI focus averages around 54 mpg. Nowhere near 70. And haven't really seen anyone average near that much. Regardless of 1.6 or 2.0 TDI's.
 
LPG is about 20-25% less efficient than petrol, nothing to do with the system or the age of the system as they have not really changed in 20 years. The LPG system piggybacks off the ECU and will be injecting in to the manifold as close as possible to the petrol injectors. The engine is made to run on petrol, the ecu readings are based on the petrol injectors being a particular distance from the cylinder, it will never be exactly as it is on petrol.

Personally I've seen big savings on the BMW (I run about twice as many miles per pound lpg vs. petrol), however it's not been without it's issues. It can be a bit finicky starting warm, due to needing to start on petrol but there still being lpg in the manifold/cylinders, my LPG also now needs a service as it's running lean.

I'm glad I went LPG, it made the car affordable. I wouldn't buy another LPG car again, though, having to travel to specific petrol stations and only having a relatively low range (~170 miles from a 80l tank) can be a pain.
 
Seems pointless on a car which is low value and has good economy anyway. There are downsides to LPG as mentioned above, availability isn't great and range isn't too good. I liked it on my GS300, was a way to run a lovely petrol engine car with the fuel cost of an agriculural diesel car. The Honda seems to have diesel-esque fuel economy already though.
 
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