Thread: How to improve 4.6 economy

Hi,

Reading this with great interest, since i am currently getting a "Left Bank too lean" message.

I think cleaning my MAF is in order

Steve

Hi

Just a quick note on this, I was reading this thread about adaptive values and it is has some interesting info about airflow rates etc

http://www.rangerovers.net/forum/7-r...s-reset-2.html

Essentially it seems the things to check before you mess about with anything are

1) Coolant temp should be in in low-mid 90's Mine seems to run around 93-95

2) MAF should be cleaned

3) TPS should be checked

4) Vacuum hoses need to be checked for air leaks

Steve

Just to give some perspective. I had 2 prados previously, both on LPG, the older one had the old style system and was around 15-16l /100k's the 03 we had fitted with LPG injection and was 12-14 loaded with 2 adults, 3 littlies , full boot,but nothing on roof, gong to gold coast.This is on a 4.0 v6 that way loaded would still be 500 kg lighter and not as nice to drive as a RR with a 4.6. So along with the 20% weight penalty you've also got heavy drag with a roof rack full and are only using 20% more fuel, not to bad.

Ok,
Just spoke to Ward of Graeme Cooper Auto in Sydney, he is saying that 17.2 is pretty good for what I had on board ( mirrored your comments Hoges ).

He also said that you could gain a little from free flowing cats and minor remapping of ECU, but essentially what you see is what you get from this vintage V8 ( Thor with 193000km ). Anyway he's going to have a look at whats going on with the O2 sensor on Thursday

Thanks Rupert for your offer, I'm at Engadine not too far from you, and I feel your services will be required at some point of my ownership!

Having said that I noticed another post on fuel economy when towing a trailer has just popped up, I'll be watching with interest.

Missed the bit about the roofrack. When we had the classic we were looking at a roof top tent, but after a trip with swags on the roof never again!

Originally Posted by benji

Missed the bit about the roofrack. When we had the classic we were looking at a roof top tent, but after a trip with swags on the roof never again!

Benji,

If your referring to me, see below.
The more I look at it, the more it looks like a massive wind break

Rob

Great to see a P38 in its "natural" environment !!
A lightweight aerofoil to deflect the air flow over the roof rack would probably make a significant difference...

Originally Posted by Robsrod 58

Ok,
Just spoke to Ward of Graeme Cooper Auto in Sydney, he is saying that 17.2 is pretty good for what I had on board ( mirrored your comments Hoges ).

He also said that you could gain a little from free flowing cats and minor remapping of ECU, but essentially what you see is what you get from this vintage V8 ( Thor with 193000km ). Anyway he's going to have a look at whats going on with the O2 sensor on Thursday

Thanks Rupert for your offer, I'm at Engadine not too far from you, and I feel your services will be required at some point of my ownership!

Having said that I noticed another post on fuel economy when towing a trailer has just popped up, I'll be watching with interest.

PS. Does anyone have a long range fuel tank they don't need any more??

If he can remap the Thor ECU I'd be most interested... there was some discussion on this elsewhere but to the best of my knowledge...fed from reports of enthusiastic BMW forum posters whose late 90s 3-series had the same Motronic set up, it's virtually impossible to remap the ECU because the BMW engineers in league with the Bosch folk made it "very" proprietary to prevent virtually any other tune state added to which if it's altered more than a dozen or so times, ...for example make a change save, rewrite save etc as you do with incremental changes... the ECU miraculously assumes the guise of a "brick" !! Which raises the question as to whether some smart cookie might be able to adapt the tuneable GEMS architecture to a Thor engine for improved performance taking advantage of the Thor manifolds which I'm told improve low end torque....