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E53 4.4 LPG Real World MPG

Posted: Fri Jul 21, 2017 8:05 pm
by davrostavros
Hello all,

Just done my first to the brim fill up and I was wondering what MPG people are getting.

I have a BRC LPG conversion and for the first one it seems that I am on about 12 mpg.  I thought I would be getting closer to 20 (OBC showed 19.6) but Im curious as to what everone else is getting.

Loving the V8 sound on the powerflow exhaust though.

Re: E53 4.4 LPG Real World MPG

Posted: Fri Jul 21, 2017 9:23 pm
by henrym3
Never seen 19.6 on OBC thought mine only went up to 17(joke) If I do a journey where I go from full to empty on LPG, I get 15.5 mpg. But if I'm doing that sort of distance I'm not normally hanging about. If I'm using it to go to work I appear to get more 16.5/17 but that is because it does small amounts on petrol and the speed is much more sensible. I don't seem to have a vast variation between the two.
Can't remember the last time I did more than 20 miles on petrol.

Re: E53 4.4 LPG Real World MPG

Posted: Fri Jul 21, 2017 11:11 pm
by weirdfish
The only real way to check is to fill up the lpg tank, take a note of how much it takes, and at what cost, then run until it's empty and goes onto petrol, take a reading, go and fill up again, ideally at the same cost per litre, then do the maths.
You also have to into account that you will use a certain amount of petrol everytime you start up.
Don't ever believe that you will get double the mpg because of the cost of lpg, it just doesn't work that way.
Hope that helps.

Re: E53 4.4 LPG Real World MPG

Posted: Sat Jul 22, 2017 9:47 am
by lezmtaylor
I do not worry my head about true mpg, but factoring the price of lpg reckon on between 30-35 as compared to petrol prices. There are other savings as well.
Remember that lpg is a gas and petrol a vapour , so lpg is kinder to your engine piston bores (petrol vapour is a very fine petrol droplet and washes the piston bores.)
I used to run a transport company and we had petrol. petrol/lpg and diesels powered vans. The lpg petrol engines when oil changed ,the oil came out golden, not dirty brown as with petrol.
Lpg engine bores will last at least twice as long as petrol and the plugs last a lot longer as well. It is safe to double the mileage between oil changes. (Although I admit to doing mine annually.
There is also a small saving in Road fund licence fee, I do not remember how much as I am disabled and get e concession.
I seem to remember that the exhaust fumes are a lot less dangerous as well, I also finished my working life as a Forklift engineer and remember that lpg forklifts were safe to use in enclosed factory areas, and the engine oil was always a golden colour on change.

So the first thing I did when I purchased my 2002 4.4 with warrantee from Cotswold Gloucester in 2006 was have the lpg conversion done, I was assured that the warrantee would still be honoured and within the warrantee period the auto gearbox was changed and the instrument pod suffered pixel failure and was renewed.
If anyone is considering purchasing an lpg already fitted vehicle / or is contemplating the conversion make sure it is properly certificated and registered with the UKLPG Autogas authorities
.
Also I would recommend fitting a new battery (the donut fuel tank sits on top of the battery and is a sod to get out) also make sure that flexible hoses are fitted from the fuel tank right through to the engine, solid wall pipes will break on tank removal ( I know !!)

Lez

Re: E53 4.4 LPG Real World MPG

Posted: Sat Jul 22, 2017 9:50 am
by IanP
You will get less MPG on LPG as the fuel has a lower calorific value per kg than petrol. Cost per mile will be substantially less though.

Re: E53 4.4 LPG Real World MPG

Posted: Sat Aug 26, 2017 6:21 pm
by Rathian
I get between 17-19 mpg on lpg. 75 mile commute to and from work mainly motorway 60-70mph. Can't remember the last time I did a petrol run but think it was around 22mpg. The trip computer is way out reading 25.4mpg almost every time I reset at fill.


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