Disco V8 fuel consumption.

People Hi,

I would be extremely obliged if you could provide me with a rough figure of how many miles a 3.9 V8 engine Discovery could make on a fuel tank.

A friend here in Greece gets around 200 miles (up to 230 occasionally) and I think this is pretty low.

Take care Pantelis

Reply to
Pantelis Giamarellos
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On or around Sun, 3 Jul 2005 09:36:42 +0300, "Pantelis Giamarellos" enlightened us thusly:

you've got a 90 litre tank. 20 gallons, for them of us that think in gallons still. The 3.5i here does about 18 mpg on petrol, and thus would get about 360 miles per tankful. 3.9s are normally reckoned to do a bit better, but it depends how and where you drive, obviously.

Reply to
Austin Shackles

I used to fill mine after 300 miles as a rule. I once ran to 340+ when lost in the middle of nowhere with a very very pregnant missus in the passenger seat. Nervous.... only a bit!

Generally reckoned on 18mpg, though 20 could be coaxed from it on long and gentle cruises. Boot it about town and it could drop to perhaps

16mpg. 200 miles seems pretty bad - that would suggest 10mpg if he really is emptying it - how much is he putting in when he refills it? As Austin says, it's a 90 litre tank.
Reply to
Tim Hobbs

?im Hi,

I also fear that my friend's Disco V8 has a serious problem either with the general condition of the engine or the Efi or ignition system.

Take care Pantelis

Reply to
Pantelis Giamarellos

Tim Hi,

Murphy's law dictates that running out of fuel can only happen whenyou are in a hurry.

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I think that he fills up the fuel tank properly. He gets around 340 kms on a regular basis and even goes down to around 300 to 310 kms when he steps on the go pedal.

and yes he does have the 88,7 litres fuel tank and not the smaller one that Discos used to have in the start of the production live.

Thanks again for everybody's input.

Take care Pantelis

Reply to
Pantelis Giamarellos

ICBW but I would have thought that a 50% loss of fuel economy would show some fairly obvious performance losses or exhaust garbage as well. It should pull smoothly and fairly strongly from as low as 1000 rpm without hesitation, and rev to 4500 through the gears.

Reply to
Tim Hobbs

On or around Sun, 03 Jul 2005 11:38:29 +0100, Tim Hobbs enlightened us thusly:

If you nail it, it should rev to about 5500...

Reply to
Austin Shackles

Tim Hi again,

To be frank with you I have not asked him about the general feel of the engine but i will be asking him tomorrow when I speak with him again.

Take care Pantelis

Reply to
Pantelis Giamarellos

Austin Hi,

5.500 rpm sounds a bit high for the LR/RR V8. But then again I am used to the Tdi in Landies and even 4000 rpm is way too much for those lumps of iron (Tdi I mean)

Take care Pantelis

Reply to
Pantelis Giamarellos

It doesn't like it though. You can feel it begging to change up after

4500, and someone (Badger?) said something once about it being quite bad for the lifters as they pump up.... Or something....

After the new cam mine was noticeably happier to rev and felt OK up to

5000. There isn't much to be gained up there though - it doesn't seem to produce much more power beyond the mid 4000's. Oddly the new cam didn't seem to do anything for the fuel economy though, although there was other buggering about for LPG done at the same time so it wasn't a true comparison.

Back to the OP - are there are any visible problems such as erratic idle, colourful smoke or misfiring? Does your friend live at the top of a mountain - not joking, when I moved away from Sheffield (where everything is on a steep hill) my Peugeot of the day used a lot less fuel.

Reply to
Tim Hobbs

Tim Hi,

my friend lives next to the sea. Higher altitude always means less performance or more fuel consumed in order to produce similar performance. It has to do with the oxygen in the air which reduces the higher you are. Plain matter of life on earth.

I will ask my friend about how the engine feels in general and whether he gets any smoke or erratic idle etc.

Take care Pantelis

Reply to
Pantelis Giamarellos

We get 200 miles per tankful. I have been to RPi and they checked everything out but the only thing wrong was a split diapram in the bit on the side if the dizzy. Must be the way I drive!

Richard

Reply to
Richard

On or around Sun, 3 Jul 2005 16:25:48 +0300, "Pantelis Giamarellos" enlightened us thusly:

well... looking in the books:

early RR V8 - peak power at 5000 later 3.5s - 4000 carb, 4750 injection.

3.9s - low comp 4550, high comp 4750.

official disco manual quotes max power at 5000, for a 3.5

but that's the peak power figure, not maximum permissible speed, which none of the books seem to list.

Reply to
Austin Shackles

Not had mine that long but half a tank got me to 95 miles easily, probably do a 100 miles but don't really want to run out of fuel!!.

Dom J

Reply to
Dom J

Well, to be pedantic the proportion of oxygen in the air doesn't change much. However, the air is at lower pressure and therefore there is a less mass of air (and hence oxygen) drawn in on each stroke. Turbocharging helps substantially...

Reply to
Tim Hobbs

Tim Hi,

reduction of oxygen due to lower barometric pressure as altitude increases was the main reason why turbochargers and superchargers were invited and first applied in airplane engines, at least this is what the books write.

Richard and DomJ I guess for every two person quoting a proper fuel consumption for a V8 two more exist quoting a fuel consumption of around 200 miles per tankfuel. No wonder then that the V8 is considered a fuel thirsty engine by most. But I think that 200 miles is a bit low for a 90 lt. fuel tank even if this is done by an american designed 1960's engine.

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Forgot to also mention that my friend's engine has starting problems with the starter turning OK but the engine not firing up on the spot. Occasionaly, and usually when he is in a hurry, it may take up to 15 minutes to fire up properly.

Take care Pantelis

Reply to
Pantelis Giamarellos

On or around Sun, 03 Jul 2005 21:29:11 +0100, Tim Hobbs enlightened us thusly:

This is why your engine runs best at low altitude, on a frosty dry day, and worst at high altitude, in humid conditions in midsummer.

Doing a regular route on the same roads, you can actually detect the differences that day-to-day weather changes make, even at the same altitude etc.

Reply to
Austin Shackles

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