# Check My Figures



## 100790 (Aug 30, 2006)

I appreciate there have been a number of posts on this forum with regard to LPG conversion. But I would appreciate any feedback on my figures/calculations which are leading me to splash out on a conversion. Well here goes:

Cost of conversion: £3000. This is equal to 709 gallons of petrol @ 94p per litre. On average I get 10 mile to the gallon towing a trailer. So for £3000 I would get 7090 miles. Last year I covered 4500 miles and I am on target to repeat this again this year.

I believe that with LPG I will get 8 miles to the gallon at a cost of 43p per litre or £1.94 per gallon. Would I be correct in assuming that for the cost of a gallon of petrol, £4.23, I can buy 9.8 litres of LPG, giving me 16 miles for the same price as a gallon of petrol.

4500 miles on petrol = 450 gallons @ £4.23 = £1903
4500 miles on LPG = 562 gallons @ £1.94 = £1090
This would give me a saving of £813 per year. Therefore after 3.6 years I would start to save money?

Everytime I go through this thought process I come up with different costings/savings. 

I would really appreciate any feedback on these calculations or indeed anyone elses calculations. Does an LPG conversion increase the value of your RV? If so how much.

Many thanks
Geoff


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## johng1974 (Jan 17, 2007)

hi Geoff that all looks ok..

Yes, LPG should add value / or make your vehicle more likely to sell quicker at a good price, if that makes sense? esp in UK..

John

edit..
or.. you could remove the system and add to a similar engine when you upgrade the RV...


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## 97993 (Mar 5, 2006)

Hi Geoff
As you rightly say this subject has been discussed before and the out come "appeared" to be you need to cover at least 20- 25000 miles to break even, the period of time was and is irrelevant
your figures look good on paper try again with 5-6 mpg on gas and see how that compares, gas has a lot less power output resulting in a harder right foot, I have spoken to two RVers one this weekend as it happens and both said they would'nt do it again.your best info will of coarse come from those that have paid out and reaped the benifit, but they are very thin on the ground, the best option is always to buy an RV already converted then it's a Win Win situation
Geo


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## asprn (Feb 10, 2006)

The main variable in your equation however is the question of the price of LPG. Did I not read that there may be a possibility of a substantial increase, bringing it more in line with other road fuels?

Dougie.


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## Scotjimland (May 23, 2005)

There is more to the equation than simply cost, if you have a choice I would go for a diesel, if you intend to travel further afield LPG is not available in Spain nor Morocco. 
Diesel engines also give much better MPG, my Cummins returns an average 14mpg pulling an 8.5ton RV plus a trailer. 
As pointed out, LPG is rising in price, the same scenario as diesel a few years ago when the gov. encouraged diesel ownership only to push the tax up once it was popular :roll:


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## olley (May 1, 2005)

Hi this is from forecourt trader Dec 2006: 

Meanwhile, the LP Gas Association said it was pleased to see continued support for LPG through low fuel duty. A duty increase of 2.25ppl confirmed the Government’s commitment that the differential between LPG and standard fuel would reduce by a maximum of only 1p per year, ensuring the price at the pump will continue to be around half the price of petrol and diesel.

Thats 6 months ago. Mind you a week is a long time in politics. :lol: 

Olley

PS just found this from Auto LPG May 2007:
"LPG autogas is now well- established with strengthened government support in the last Budget guaranteeing the fuel duty for three years. This means that the price of LPG at the pumps will continue to be around half the price of petrol and diesel for the foreseeable future."

Current fuel duty on LPG is 6.105ppl compared with 48.35ppl on petrol and diesel. Between now and 2010 the duty on LPG will rise by 6.305ppl to 12.41ppl while that on petrol and diesel will rise 5.84p to 54.19ppl.


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## 95633 (Jul 4, 2005)

Hi Guys

Sorry if this has been covered before.

Is there any way of reclaiming the Duty on LPG ?

Am I correct that the Duty is for road use and not domestic use ?

I'm only using 40 litres a month at the moment (probably 80 in the winter) so the Duty element is only £2.50 per fill.

But if there was a simple form which I could send off each year with receipts, it will be worth the cost of a stamp and 10 minutes work - even £35-£40 is worth reclaiming (don't give the buggers any more than you have to )

Paul


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## 100790 (Aug 30, 2006)

Many thanks for the feedback so far, please keep them coming, would love to hear from someone who has converted to LPG.

:? GEO: would appreciate if you could expand on the need to cover 20 to 25K miles before reaping the benefit.

ScotJimLand: All ready own an RV which I improrted myself. Agree with diesel as the best option.


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## olley (May 1, 2005)

hi Geoff had mine done in 05, I don't notice any difference in running on LPG or Petrol. My own feeling is payback will be nearer 25,000 miles, done about 15,000 since we had it done. 

Would I have it done again on a petrol RV? yes absolutely.

LPG is available in Spain but scarce is an understatement. :lol: 

Olley


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## Pusser (May 9, 2005)

I know nuffink about these sort of figures but I had the feeling that from time to time you will have to use diesel too. This may affect figures


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## olley (May 1, 2005)

Pusser said:


> I know nuffink about these sort of figures but I had the feeling that from time to time you will have to use diesel too. This may affect figures


diesel? in a petrol engine, not if you want it to run. Mind you because of that a tank of diesel would last a lifetime. :lol:

Olley


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## 98452 (Apr 2, 2006)

If I was capable of keeping a vehicle 3 years it might just start paying for itself.

I can tell the wife i intend to keep a vehicle that long (but experience says it will NEVER happen :roll: )

I don't think that a vehicle will be worth an extra 3K when selling it maybe a grand and a quicker sale :wink:


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## G2EWS (May 1, 2006)

Hi Geoff,

I have posted this a few times, but based on research done a few years ago and putting your figures here is your pay back time:

Monthly mileage: 375
Petrol mpg: 10
Petrol cost per litre: £0.94
Monthly Cost: £160.26

LPG mpg: 8
LPG cost: £0.43
Monthly Cost: £91.64

Savings per month: £68.62
Annual savings: £823.48
Cost of install: £3,000
Payback in months: 43.7


Basically you need to account for about a 10 - 20 % reduction in consumption.

I have this on an excel spreadsheet that I will get my son to put on our web site tomorrow. I am out of the office but I will ask him to put it on first thing. Just go to our web site (pm'd to you) and scroll down to the bottom of the page and I will get him to put on as .LPG Spreadsheet.. The figures you need to adjust are the only ones available but you can unlock the spreadsheet and adjust as required. The password is on the sheet.

Regards

Chris


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## 97993 (Mar 5, 2006)

> would appreciate if you could expand on the need to cover 20 to 25K miles before reaping the benefit.


Hi Geoff no personal experiance other than the comments from folk who have done it, and all the general info taken from here and other forums,
if I could convice myself that a break even point was around the 15-16000 mile area I would convert mine, but as a low milage user even 16000 would take forever and £3000 buys a lot of fuel,I also see a huge hike in the revenue as it becomes more popular 
Geo


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## 95633 (Jul 4, 2005)

Perhaps another thing to think of is the cost for any upkeep or repair of the LPG tank.

Would the LPG tank affect the warranty for the engine and/or body ?

Also, how much does the LPG weigh as this will affect the MPG achieved.

How much would £3,000 earn in interest - maybe just £150 in year 1, £75 year 2 and £30 year 3 (as it reduces due to it being spent on fuel) - but that £250 should be put in the equation.

Finally, do you lose storage space when installing an LPG tank?

Personally, 3 or 4 years is a LONG time to wait for payback.

Paul


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## johng1974 (Jan 17, 2007)

the other way that is worth considering is to buy the kit , say new from ebay, after research, and give to your local fitter and then just pay labour...

to be honest, a lot of the fitting is quite easy, leave the hard bits to them..

there are many manuals I believe that advise correct installation, etc etc

I am sure it would be easy to get the total cost down to 1000.. - I have asked fitters about this and it is feasable..

would mean a weekend on the van....

John


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## olley (May 1, 2005)

Hi an LPG tank cost's as much to maintain as a petrol tank, zilch. Repair, as far as I know this isn't possible due to safety concerns.

LPG tanks don't effect warrantes.

About 2 litres to the kg. So I increase my weight with a full tank by about 85kg plus about 40kg for the tanks, on a vehicle that weighs 8500kg, hardly significant.

can't argue with the interest. :lol: 

Depends were you put the tanks, mine are underneath behind the fuel tank, people do put them in lockers, so yes you can lose space.

Payback depends on yearly milage, but 3-4 years sounds about right, but don't forget the increase in retail value when you come to sell.

And the smile on you face when you put 170litres in and the bill comes to only £68 "Priceless" :lol: 

Olley


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## G2EWS (May 1, 2006)

Put the excel spreadsheet on the bottom of our web site which allows you to look at relative costs for lpg conversion. You can go into it and change the figures as necessary.

www.swi.org.uk

Just scroll down to the bottom of the first page and click on 'LPG Spreadsheet'

Regards

Chris


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## 97993 (Mar 5, 2006)

> £68 "Priceless"


Olley my argument was going soooooooooo well you just had to spoil it :lol:
Geo


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## 100790 (Aug 30, 2006)

Thank you to all for the much appreciated comments and advice. After much deliberation I have decided to go for the conversion (sounds like a sex change).

WHY some may wonder. Well all I can say is that as we travel further a field to race meetings the cost of fuel is increasing and everytime I pull into a service station I can see the attendants eyes light up and my wallet empty. As we intend to keep the RV for some considerable time I am hoping that it will eventually pay for itself, which according to my calculations and a residual value of £1000 will be about 2 years. Cost of conversion £2650 with 2 x 115 litre tanks. Just wish I had made the decision when we first bought the RV some 18 months ago.

Once again many thanks


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## 102138 (Dec 17, 2006)

GEOFFs 125
We had V8 Discovery converted several years ago, the only thing we would change is the tank size, we use the rear load area for work, so could only put tanks under floor, only gives about 150 mls range, this is really frustrating on longer runs (which we do quite a few each year). The main work vehicle is now a Land Rover diesel which gives us about 350 mls range on a tank.
As other RV owners have said in the past , it is wise to have a filler on each side of RV as even with Landy & trailer it can be akward to get to pump.
GOOD LUCK Nigel & Pamala


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## Moandick (Nov 8, 2006)

*Dual filler sockets*

Hi Geoff

Oh, how I agree with Nigel and Pamela - when you are converted, for goodness sake, insist on being able to fill the RV from either side. The extra 'filler socket' will cost a couple of hundred pounds at the very most - but it will save you hours and hours and hours of frustration looking for a pump which is located on the 'correct' side of the vehicle!
We had one RV where the petrol cap was one side and the gas was the other - and invariably we had to go to two separate filling stations in order to fill both tanks because we could never get the RV close enough to the relevant tank to fill - if we had known about dual fillers then, we may never have changed our RV.

Dick


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## 100790 (Aug 30, 2006)

Dick, Nigel and Pamela many thanks for the tip. I will definately take up your advice.

Dick: Do you think your conversion was value for money and how long/mileage do you think you will start to recoup your costs.


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## Moandick (Nov 8, 2006)

*LPG Conversion*

Hi Geof

Do I think it was worth having an LPG conversion - financially yes BUT:

Our tanks had been 'hung' underneath the chassis 'I' beams at the very tail end of the RV with the result that I only had to drive over a matchstick with the front wheels - and the tanks would scrape the ground. Getting onto or off of Ferries was an absolute nightmare of heart stopping proportions.
I believe that nowadays the tanks are suspended between the chassis elements and are protected from grounding.

We had our petrol tank reduced in size in order to fit the largest possible gas tanks - with the result that we could only get about 130 - 150 miles out of the LPG tanks and 130 - 150 miles out of the petrol tanks so we were always looking for somewhere to refill one or both of the tanks. Pain in the butt! And remember at that time we didn't know about dual sided fillers.

We never travelled on the Continent with our RV so cannot vouch for the availability of LPG over there - but in this country LPG is exceedingly widespread on petrol station forecourts so getting LPG nowadays is even more easy than it was three or four years ago.

Having said all of that, Mo had a problem with getting into the front seat, over the engine casing, so we had to change to a diesel pusher in order to give us a flat floor entry to her seat.

Would we ever get another petrol/LPG conversion - yes we would providing we could get one with a 'flat floor entry' to Mo's seat (access for the wheelchair).

We are full-timers and had a brand new Forest River Georgetown 36ft Twin slide with the 8.7L engine and we ALWAYS towed a two ton car/trailer combination. 
We had the Georgetown for exactly 1 year, covered just over 4000 miles and returned a maximum of 9.28 miles per gallon (or an average of 6.16 miles per gallon). 
Unfortunately we didn't differentiate between mileage done on petrol to mileage done on LPG but we spent over £1500 on LPG compared to £500 on petrol.

Dick


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## 100790 (Aug 30, 2006)

Just to let you all know that I had the LP Gas conversion done some 6 weeks ago and I am really pleased with the conversion and the mpg return.  

Matt, who carried out the conversion, spent a hour or so looking over the RV and listening to what I wanted. He managed to fit the two tanks in between the chassis members at the rear, after removing the spare wheel. The tanks are higher than the spare wheel was and above the two anti-grounding brackets on the rear chassis cross member. Thus reducing the chance of damaging the tanks as this was my main concern as some of the motocross tracks we visit often involve travelling across some rough terrain. Fillers were fitted either side of the RV.

With two full tanks and towing a trailer we get 255 miles. Cost of LP Gas £61.60. Averaging 9 mpg of LP Gas or 18 miles per the same price as a gallon of petrol. A recent journey, without the trailer, averaged 10 mpg of LP Gas or 20 miles per the same price as a gallon of petrol. Most of the mileage has been done on A roads with some duel carriage way, so I think the mpg will be higher on the motorways. As for a drop in power, to be honest I have not noticed any, even when negotiating some large hills, but then with a V8 7.4 litre engine there is more than enough power.

The spare wheel has been mounted on the rear bumper (4 inch box section) with a carrier and cover supplied by Linda at Stateside Tuning.

Geoff


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