My 3.9 V8 disco not very fuel efficient! help!:(

eeehhhh? Bet you got all excited then:rofl:



Seriously though, I stuck 30quid in her before I left work the last night and she got me home, to work and back today and shes empty again, bare in mind I live about 10 miles from work.
Think Ill stick to filling her with LPG, just have to go out of my way to get the bloody stuff!


This serves as a warning to anyone thinking, oh I can afford to run a V8:scratching_chin:

No... no you cant.

Think you've got a problem if you're only doing £1 for a mile......

think he does have a problem, i can get 8mpg out of my 16ltr v8

Scania engine may be better than an rv8 though

:scratching_chin: Fo sho? I thought they were all that bad...? I figure the light will come on half way to work tomorrow and Ill need to fill up again before I come home, this not normal?

Should get at least 15mpg

Dr_evil said:

Should get at least 15mpg

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Forgive me for asking whats probably a very stupid question but, If its got no back box on, just a straight pipe...would that effect mpg?:suspicious:

Can't see why it'd take it that far down.

are your fuel lines all good?? no holes??

Dr_evil said:

Can't see why it'd take it that far down.

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hmmm I just assumed that being as aero dynamic as a house brick, pushing 3 tonne in weight, and of course the 3.9 litre V8 engine they were all that bad. I normally stick to lpg so I hadnt noticed This worries me...how much does it cost to have an engine tuned?

basher79 said:

are your fuel lines all good?? no holes??

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Id have to go and lift up her skirt and have a look around but I assume so, never noticed and trails or puddles or anything:/

GREENHORN said:

hmmm I just assumed that being as aero dynamic as a house brick, pushing 3 tonne in weight, and of course the 3.9 litre V8 engine they were all that bad. I normally stick to lpg so I hadnt noticed This worries me...how much does it cost to have an engine tuned?

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More like 2.25 tonnes iirc

What speed do you drive at ? That could explain it but 55-70 should not be thy low

There is definately something wrong with your engine. My tuned 3.9 on carbs and straight through exhaust can still manage at least 15 mpg.

I drive like a normal person...
Scrap that normal people drive like pricks!

I drive a 2.25 tonne piece of metal that will do someone else a lot of damage if I hit them...
In other words, carefully.
I have no reason to drive like a #### and rag the **** out of her. Thats not what its about

So why do you think this may be?

I had an old 2.5 petrol that got me about 10 miles on £20.. needless to say it was removed ASAP.

Sounds like you have a fuel leak to me, it doing about the same as mine is with its fuel leak, mines on the return line so aslong as the engine is running its still pushing petrol round causing a low pressure leak.

loudandproud205 said:

Sounds like you have a fuel leak to me, it doing about the same as mine is with its fuel leak, mines on the return line so aslong as the engine is running its still pushing petrol round causing a low pressure leak.

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If this is potentially the cause, would it be easy to locate? If so could I do it? with very limited mechanical experience...

run it then have a sniff around the bay and fuel lines back to the tank, may even see drips

could be leaky regulator or possibly just over fuelling, you tried pulling the plugs to see what they look like ?

What sort of 10 miles to work driving do you do? I have a 2.0petrol focus for my economic car. I used to drive 15 miles each way to work, mostly A roads with high speed getting 35mpg. Now driving 4 miles a day through a town and getting 28mpg. Same car, same fuel garage, same driving style.

If you are driving lots of stop start and traffic that could explain it. But still a fookin lot of petrol.

I'd be interested to know what u find with this as I have the same issue and cannot find any leaks however I get around 13mpg on gas so it's confusing runs and drives ok on both. Only used it on petrol a few times as I'm not rich enough!!!!