Thread: Improving fuel efficiency v8i

Originally Posted by Thommo

This owning a V8 Land Rover thing has been the most cost effective and cheapest automotive experience of my life.

What else have you owned?

Originally Posted by Dougal

What else have you owned?

Lots and Lots of V8's..........(and a couple of 4's & 6's)
and even with most of my V8's fuel has usually amounted to only a fraction of the running costs:

speeding fines (back when speeding was not a capital offence)
breaking axles (including very expensive ones)
blowing up diffs (including a few 9")
dropping valves (well revving past 10K will do that)
disintegrating transmissions (not even a rock cruncher muncie survived my speed changes)
replacing cams, carbies etc etc.

I had an "electrical fault" once that resulted in a $10K complete rebuild.....the piston went thru the block and knocked the alternator bracket off LOL

And as most enthusiasts here will know.........whilst we have the motor out! well I might as well replace this........then that..............and while I am at it lets rebuild the whats'it and of course recon the doohickie. Those of you with oil in their veins will know and understand. For others you will never know (lucky you)

This "off road" 4x4ing in a Land Rover has been the cheapest automotive experience I have had. Should have given up my "on road" activities years ago. Once I start fixing a few things with my D1 the price of a years worth of fuel for a V8 wont even register a dent in the overall cost.

Thommo
"Fuel is the cheapest part of 4x4ing"

Ask this question...do you want better fuel economy or better fuel efficiency?

We were having this same discussion with the Master of all 14CUX's a few weeks ago when Mark Adams came to Dubai to do some mapping.

When you buy one of his ECU Eproms he will guarrantee that you get better fuel efficiency from your V8.
Using one of his maps will most definatly boost the HP and torque of your engine....but his biggest selling point these days is the improved fuel efficiency that better mapping offers.

If it's simply better economy that you want....remove any excess weight...this is a huge factor, run standard size tyres with the correct pressures, take of the roofrack etc....
LRO did an article with Britpart a few months ago on how to get the best fuel consumption out of a Defender TD5.....they basically ran it in the same mode as I descibed above and it weighed about 800kg.
Some people will increase their tyres pressures to get better economy but you end up buying new tyres sooner than you normaly would which negates any savings.

Originally Posted by Thommo

Lots and Lots of V8's..........(and a couple of 4's & 6's)
and even with most of my V8's fuel has usually amounted to only a fraction of the running costs:

speeding fines (back when speeding was not a capital offence)
breaking axles (including very expensive ones)
blowing up diffs (including a few 9")
dropping valves (well revving past 10K will do that)
disintegrating transmissions (not even a rock cruncher muncie survived my speed changes)
replacing cams, carbies etc etc.

I had an "electrical fault" once that resulted in a $10K complete rebuild.....the piston went thru the block and knocked the alternator bracket off LOL

And as most enthusiasts here will know.........whilst we have the motor out! well I might as well replace this........then that..............and while I am at it lets rebuild the whats'it and of course recon the doohickie. Those of you with oil in their veins will know and understand. For others you will never know (lucky you)

This "off road" 4x4ing in a Land Rover has been the cheapest automotive experience I have had. Should have given up my "on road" activities years ago. Once I start fixing a few things with my D1 the price of a years worth of fuel for a V8 wont even register a dent in the overall cost.

Thommo
"Fuel is the cheapest part of 4x4ing"

Thanks, that puts it into perspective nicely.

Two tonne & the aerodynamics of a Besser Block does'nt help with economy either but unfortunately we are stuck with both if you keep it.

Originally Posted by 4bee

Two tonne & the aerodynamics of a Besser Block does'nt help with economy either but unfortunately we are stuck with both if you keep it.

Dont forget drivetrain losses - turning lots of big gears in heavy oil takes its toll also.

Originally Posted by Dougal

If you can find a BSFC map for these engines then you can pick exactly where's the best point to run it.
Generalising from the othe petrol BSFC maps I've found, the absolute best point is found at an rpm around 2/3-3/4 of max torque with the pedal almost buried.

Of course if you don't need that amount of power at your cruising speed, you're best to raise your gearing to drop the rpm. Basically find the power you need and follow that constand power curve across the map until you find the lowest fuel consumption.
These maps are created from measured results, so they include all the effects of valve timing, spark timing, your engines VE characteristics etc.

Here's a prius BSFC map:


Here's an audi W12 BSFC map:


Opposite ends of the spectrum, but the generalisations still hold.

Can you tell me from what book, site or etc. you got the BSFC map of the W12 engine?

Is it from the 6.0L W12 engine of the Audi A8 (2005-2010)?

I'm interested to hear if Tommo and others on this post in 2008 are
Still members and what they drive now?

Cheers

Baggy