Why do you have a V8 ?

Yeah granted the v8 cars are cheaper than the diesels.

Take a 300 disco 1 for instance, are the diesels around 1k more than the equivalent petrol?

Wouldn't take long to use 1k in fuel in my book, 2 months regular use or a handful of long laning weekends...

Mr Noisy said:

Yeah granted the v8 cars are cheaper than the diesels.

Take a 300 disco 1 for instance, are the diesels around 1k more than the equivalent petrol?

Wouldn't take long to use 1k in fuel in my book, 2 months regular use or a handful of long laning weekends...

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People seam to be talking about getting 28mpg on their diesels. Vs 20mpg in the petrol. Would take a while to spend 1k on fuel. I was driving mine daily and didn't spend 500 a month on fuel.

Mr Noisy said:

Yeah granted the v8 cars are cheaper than the diesels.

Take a 300 disco 1 for instance, are the diesels around 1k more than the equivalent petrol?

Wouldn't take long to use 1k in fuel in my book, 2 months regular use or a handful of long laning weekends...

Click to expand...

I think you missed the OP question, it's suppose NOT to be about money/cost between the two.

rangy35 said:

I think you missed the OP question, it's suppose NOT to be about money/cost between the two.

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Yeah I know my mate that's why I bust £200 in fuel on a 350 mile laning weekend and deal with it, which brings me onto the next point, in mine with my setup, yeah £500 a month on fuel would be a breeze if I used it more than once twice a month with the type of usage it gets, it ####ing drinks like a thirsty fish!

That said, now that the 1.4 transfer case is in its time to work on the MS tuning to try to work some more economy out of the damn thing on the motorway, 12mpg is not my friend!

SnowmanV8 said:

Vs 20mpg in the petrol.

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20.. if you'r Mrs push's it maybe :tea:

discomark10 said:

20.. if you'r Mr's push's it maybe :tea:

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Before the engine started on its downward slope. It ran 3 tanks at 19 average :-D

The previous owner reckoned, on long run he was getting 21mpg out of a 3.5 carb on a 3 speed auto.

Mr Noisy said:

Yeah I know my mate that's why I bust £200 in fuel on a 350 mile laning weekend and deal with it, which brings me onto the next point, in mine with my setup, yeah £500 a month on fuel would be a breeze if I used it more than once twice a month with the type of usage it gets, it ####ing drinks like a thirsty fish!

That said, now that the 1.4 transfer case is in its time to work on the MS tuning to try to work some more economy out of the damn thing on the motorway, 12mpg is not my friend!

Click to expand...

I don't want to hog this thread but seems its to late.......could you link me to your 3.5 rebuild, I am interested to see your set up and I want to discuss some things rater there.

On the motorway drive the V8 with a constant rpm rather than a constant speed.

As far as I know fuel consumption is directly related to intake pressure (throttle position). More intake pressure (throttle down) means more fuel consumption. Even when no actual acceleration takes place. Most cars do not have intake pressure indicators, so we'll have to do with the rpm indicator. Keep your rpm's constant and your foot still.

My V8i gets into a nice cadence at 2800 rpm when it does about 70mph and reaches 22/23 mpg. (on the flat) . 2100 / 60 works also well when not in a hurry.


ps. cruise-control is disastrous for a good fuel consumption.

FlyingDutchman said:

On the motorway drive the V8 with a constant rpm rather than a constant speed.

As far as I know fuel consumption is directly related to intake pressure (throttle position). More intake pressure (throttle down) means more fuel consumption. Even when no actual acceleration takes place. Most cars do not have intake pressure indicators, so we'll have to do with the rpm indicator. Keep your rpm's constant and your foot still.

My V8i gets into a nice cadence at 2800 rpm when it does about 70mph and reaches 22/23 mpg. (on the flat) . 2100 / 60 works also well when not in a hurry.


ps. cruise-control is disastrous for a good fuel consumption.

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I might fit a vacuum gauge if thats the case. Might be worth while for longer journeys!

rangy35 said:

I don't want to hog this thread but seems its to late.......could you link me to your 3.5 rebuild, I am interested to see your set up and I want to discuss some things rater there.

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Yes pal

Just bumped it up to top in v8 section

FlyingDutchman said:

On the motorway drive the V8 with a constant rpm rather than a constant speed.

As far as I know fuel consumption is directly related to intake pressure (throttle position). More intake pressure (throttle down) means more fuel consumption. Even when no actual acceleration takes place. Most cars do not have intake pressure indicators, so we'll have to do with the rpm indicator. Keep your rpm's constant and your foot still.

My V8i gets into a nice cadence at 2800 rpm when it does about 70mph and reaches 22/23 mpg. (on the flat) . 2100 / 60 works also well when not in a hurry.


ps. cruise-control is disastrous for a good fuel consumption.

Click to expand...

Well, this is very true.

In a manual of course rpm and road speed is directly related, but you are quite right in that throttle position and thus MAP is directly related to your fueling.

Being a Megasquirt guy I am well informed as to how much fuel is going down the spout and when, and it was apparent that a lot of fuel was going down the spout in mine on the motorway.

On LR4x4 economy thread we came to the conclusion that my vehicle was overgeared and as such my throttle was too far open to maintain steady speed.

This was the reason for fitting the 1.4 transfer box, to increase revs and decrease throttle opening at given road speed.

Not done much testing yet but initial results seem good, my aim is to run at 75mph at 14.7 or 15:1 and even on my current AFR table which is setup for power it did seem like it would fall into a 14.7:1 cell at motorway speed, this is purely down to MAP at this point of course.

Anyway yes you are absolutely correct there

FlyingDutchman said:

On the motorway drive the V8 with a constant rpm rather than a constant speed.

As far as I know fuel consumption is directly related to intake pressure (throttle position). Most cars do not have intake pressure indicators, so we'll have to do with the rpm indicator.
My V8i gets into a nice cadence at 2800 rpm when it does about 70mph and reaches 22/23 mpg. (on the flat) . 2100 / 60 works also well when not in a hurry.

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Point #1 - agree, a series 5 BMW I once owned had a gauge showing consumption in 'real time' -cruising it would show well into the 40's but slight pressure on throttle to take an uphill grade it dropped to the mid twenties.
Point #2 - my V8i (totally standard) returned an average of 22mpg over 630m of largely legal limit (motorway/'A' road) driving.