SLROC Forum
General Category => TECHNICAL CHAT => Topic started by: Piwi on May 22, 2012, 12:53:13 PM
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Folks I'm not familiar with LPG, fuel consumption and running costs. What sort of Mileage would you get out of a 4.6 range rover with an 130 litre LPG tank ? And what would it cost to fill ?
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? Is this for the cost of running the 4.6 V8 P38 that was advertised?
A 130 litre tank would take 104 litres
a 150 litre tank would take 120 litres normally
The tank usually fills to 80% capacity.
20 % for the gas expansion with temp & pressure changes
if you put in 130 litres @69 pence a litre then £89.70
130 litres @ 75 a litre then £95.50
130 litres @ 80 pence a litre then £104
Out of a 4.6 V8 automatic in a 110 that i ran, which started and ran on LPG without the need of petrol.
(the one Geoff & Geoff G had.)
2.5 miles per litre minimum which was driving solo in summer,
& up to 3.5 miles per litre towing a transporter and in the winter solo.
150 litre tank would take 80% of that capacity, so
120 litres & if the gas is 75 pence a litres, 120 X 75 = £90.
2.5 miles to the litre,
120 lts x 2.5 miles = 300 miles for £90
120 lts X 3.5 miles = 420 miles for £90
if the tank is 200 litres and can be filled with 160 ltrs @ 75 pence per litre = £120
& does 3 miles to the litre, then that is 160 x 3 = 480 miles or so.
petrol is 4.546 litres for £1.32.9 ltr = £6.04 a gallon.
18 MPG & use 10 gallons =180 miles for £60.40
x 2 = 360 miles for £120.80
*So petrol for a gallon @ £6 & 18- 22 mpg maybe = £12 and 40 miles
LPG 15 litres cost @ 75 litre = £11.25 & 3.5 miles per litre= 52.5 miles*
www.petrolprices.com
You need to find the cheapest LPG supplier, usually Asda.
If an Ada Credit card is giving you an extra 1 pence a litre off, then that is an extra £1.30 saving
when fillling the tank
Be aware that as fuel rises by 2 pence a litre and you use 1.5 to 2 times the litres, the benefit of running LPG drops.
george
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In a car with a serviced and correctly operating multipoint injection kit I would hope for between 14 and 17mpg mixed driving.
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Pumps dont show gallons anymore, so around 15 miles for 5 litres,
30 miles for 10 litres.
george
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Yes but not many of us work in miles per litre!
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WAW.........
I am getting 2 mpg less on lpg and there is a noticable drop in power (but who uses full power in a v8 for very long)
The timing is still set for petrol.
Its a closed loop with a vapouriser.
lpg at asda kirkcaldy is 74.7p
shell cowdenbeath is 81p
Randolph gas in kirkcaldy is 72p (they use much more lpg than asda and change the price everytime they get a delivery)
You back up yet?
cheers.
Drew.
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Steve it just makes it quick and easy,
the reason over the years that i have looked at Miles per litre is easy, the price is so different all over the place.
When it was 50 pence a litre for ages it was easy. 5 litres or 10 litres etc.
You pull in for gas and see the price.
You know within weeks how many litres you need, how much it costs just now goes from around
67 pence to 79 pence a litre.
You see 62.9 pence a litre.
10 litres = 10 times is so easy £6.29 for a little over 2 gallons if you want to think gallons.
multiples of tens is simple.
Or 5 litres, you know that a little over a gallon of LPG is about £3.15
The petrol is £6.04 a gallon.
george
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It is only when you put the gallon in a 5litre can and gaze at how little
your 6 quid gets you.
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ffourphantomfixer,
you said you were getting 2mpg less on lpg than when on petrol.
What MPG were you getting on petrol?
george
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Thanks for all the replies . George , no its not the one youre thinking of .
So really where you make your saving is from the price of LPG rather than increased milage ?
Another question and will ultimately depend on how regularily a engine has been serviced but what are the most common probs with a rover v8 and what are the more serious issues to look out for ? Same question also applies to the auto boxes ?
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yes the only saving is the cost of gas but when you take the cost of the kits there is no saving or very little maybe a small increase in after sales value i have run v8 to 133000 miles and never had to touch it internaly and others 90000 on the clock and a change of engine and had to replace the cam followers the bigger capacity engines are prone to head gasket failure as are some that are gas converted
both engines and auto boxes if serviced regulary should outlive the body
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both engines and auto boxes if serviced regulary should outlive the body
My cat will outlive the body on a Disco 1 (so might the goldfish if the cat dont get it first) :D
George
I get 16 on petrol and 14 on gas and use the car every day. I have a problem with the idling on the car and am convinced its the cap and arm. have 3 different sets of both on with differing results. I refuse to pay 60 bucks for a "genuine" item so looking for a more permanent solution.
Drew.
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drew what size engine are you running
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Piwi,
you won't get increased mileage from LPG. I get about the same drop in mpg as phantom4. Shell petrol station on M80 at Cumbernauld costs 72p a litre. The power drop from running on petrol is noticeable, but not major. I'm running a 3.5 carb 90.
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Im running a Disco 1, 3.9 with manual box
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when I WAS RUNNING a disco 4.0 i was getting 19 mpg a 3.9 rangie auto was 22 mpg and a 3.9 manual before the exhaust was changed to a sports system was 22 mpg after it was changed i danced on the throttle and get less mileage
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I Wish :-[
I need to spend some time on it, its running fine when cold jst wont idle properly when hot, I know its gettin a good spark as it tries to idle at 250 rpm so if the spark was bad it would not idle and just cut out.
I dont drive about at 55 also its only 16 miles to work, ill get a better idea on mpg when i take it to inverness next week.
Is there anybody in scotland (Fife ish) that is S**t hot with V8's???
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I am sure they could set your timing advanced correctly to suit running LPG & have it running fine when on petrol..
www.wellsidemotors.co.uk
george
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i played about with my 3.9 the base idle is critical the co2 is critical timing dizzy and leads also cap and rotar arm are critical you have to start with the easy bits then move on to the more complicated bits the vacume diaghprame in the dizzy could also be fubared i have had several split your air meter could also be jiggered not alowing you to adjust the co2 the worst mpg i ever got was 10 mpg with a carbed 3.5 on the school run that one only returned 18 mpg just with one tankfull normally it was 16 mpg it is complicated and time consuming the first time once you have done it a lot you will be telling others how to do it
the last 25 years of v8 owner ship has been expencive but not a waste of time
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SimonBBC makes better ignition Parts that Lr now. The so called genuine rotor arms are riveted pattern ones rather than moulded. I got cap leads and rotor arm for 48 quid delivered and they are excellent. Drew when last did it have new plugs?
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Hi steve.
Serviced it last weekend, oil, filter and plugs, air filter is a K&N.
The leads I got from you are great and still on.
I ordered a new temp sender (the injection one) that was supposed to be an origional "Lucas" item, when i tried to tighten it up the plastic outer with the molded nut spun on the brass bulb so a 2 min job turned into an hour, I have never come across so much junk being sold as oe parts untill i started with Land Rovers, i have even found some britpart parts to be useless and have stopped using Paddocks as their customer service is the pits. (rant over).
In the 80s I ran, messed with, overhauled/rebuilt and lived with several V8 Sd1's for the best part of 10 years, being young and daft back then I used to go everywhere flat out, I won an autotest in one and even did night navigation rally's with the Raf in a standard one with a cage fitted and never once had problems with the ignition side of any v8, or overheating, or cracked blocks and in all that time I only had to change 1 cam due to wear and that was caused by low oil pressure.
My Disco has a crank pully that is 22degs out at tdc, has a new (not oe) mafm, new distributor, cap n rotor n leads and has never run the way I want it to run, I have to get to the bottom of it tho as i will be putin an auto in it asap.
I need to look at the distributor as the vac advance doesnt when you suck on the pipe (neither does the old one tho) and follow up on the other advice ive recieved in this thread.
I have to say that although the lpg stsyem I fitted is basic, im chuffed with it.
Asda is down to 69.7 for lpg.
keep the good advice cumin folks.
cheers.
Drew.
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Who do you guys recomend for good quality v8 ign. parts
Drew.
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I would suggest that you try it on an Airfilter that will let it breath better to see how it performs.
I know all the K&N claims and for dusty conditions and wet they are worth it,
i find they strangle an engine & may have something to do with your poor fuel economy.
Easy enough to put the K&N back on if you find no improvement with a filter suitable for the LPG.
george
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Thanks George.
Im a bit glad of the K&N as about a week after fitting the lpg i had a backfire thru the inlet and im sure it would have blown the standard airbox to pieces, i have been told that there is a higher risk of inlet backfires when using aftermarket filters.
The standard air filter when new is very good, the problem lies in the air box which is quite restrictive, just take a look at the air inlet on the airbox and compair it with the size of the hoses around the mafm, that said, the reducer is very restrictive and the engine seems ok when on petrol but i dont go much above 3000rpm.
Drew.
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How can a k&n strangle an engine? It's less restrictive than standard!
Drew google SimonBBC for ign parts, get the genuine lucas cap
With red rotor arm and the powermax leads. All are excellent quality and well priced.
Backfires are caused by lean running lpg, did you adjus the mixture after fitting the
K&n as the increased air flow will lean out the mixture considerably.
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...or go 300 Tdi. :D
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Steve,
Its not the cost of buying K&N filters that stops me using them, its previous experience of a few.
In my experience of having first used K&N Airfilters when i was a young boy racer & later having bought vehicles fitted with K&N filters they are not more free flowing than a nice clean standard filter or an actual 'Free Flowing Filter.
There can be advantages in a K&N cone possibly, but thats not certain to be the same when you put a new K&N panel filter into an airbox.
In fact i can put a Jimny on the Analyser and change between filters & clearly see how it is breathing.
(i have a K&N filter sitting almost new now, removed from a Jimny so that it could run properly)
I usually use Pipercross filters & when not worriyng about water & not with LPG i gat MANN filters for not much money.
They are nice and strong & re-usable over a length of time, many years infact.
Which comes to the point of K&N filters,
properly cleaned and re-dressed they can be used again and again.
Still does not lead to them being 'free flowing,
but if your experience with them is positive, thats great.
george
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Steve, thanks for the info, been onto their ebay shop so will keep you posted.
Genem, no thanks, id rather have a petrol.
Graeme, Its a cone filter im using, i tried a pannel filter in the BMW and apart from more induction noise any other gains were marginal. The filter im using is rated upto 400 bhp and was on my BMW, I will be refitting the standard filter box and filter so i can have a base line to start with.
cheers.
Drew.
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Interesting stuff George, I have only ever experienced k&n with a suitably freer flowing exhaust, it does make a much bigger improvement I understand. An engine is just a pump after all!
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I found a problem with the RPI engine & the big pan filter on top,
even though it was a Strengthened filter against Blow Backs, it was 'too open and exposed' to getting more air in with a gust on windy days.
On the motorway say coming through Fife and the big side gusts of wind, it was not the vehicle getting effected by sidewinds it was how the engine was running.
Blasts of air into the Defender Engine compartment could be felt in how the engine was performing.
Not a major problem but i was aware of the ambient air temp on the Gas mix between seasons and in windy conditions with a very open filter rather than one enclosed in an airbox and getting a more controlled Air Intake Temperture and flow.
Obviously the Ambient Temp changes, just not the unexcpected blast of air.
(it was a very basic system tho and no MAF or the likes)
george
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gerge the same would be true for any engine running a filter like you had efectivly part supercharging the engine then restricting it but it depends on the CFM required by that particular engine so a gassed engine is more prone to variations just imagine the differance then if it was a big 7 or 8 litre V8
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I get around 200+ miles out of 100 litre tank on my 3.9 classic, at a steady 55 to 60 mph on a run, its got nearly 200k on the clock.
coop