Fuel Trims Comparison...

[Diamond Black Geezer]

Many thanks Mr Gav.. only retards it, then. And it's Dyno-only  Fair enough.

I was hoping that a Tech 2 would be able to give date, as it can with the trims (which I've now learned it totally unconnected!  )

If you want concrete evidence of what is happening with each fuel then you would need to dyno it, that's the only scientific way you`re going to get results.

As you say there`s the placebo effect to consider when doing your own test so they`re not really worth while.

A remap would probably make a worth while difference (and it already sounds like you`ve made your mind up  ) so get it done and enjoy it and forget about a couple of mpg difference, after all you don`t get a large saloon with a big V6 engine and worry about fuel consumption 

If you`re wanting a bit more go then the best single mod you can do is get a 3.7 ex plod diff, better acceleration through all the gears and not too much of a hit on mpg 

Haha, ta again.

I suppose you could say I've made my mind up, yes, but at the same time it's a long way off, yet. I really try and do things in an order, so the bodywork is still a state, but that all waits, as with various mechanical bits like the back wishbones I want to refurb, simultaneously doing the handbrake/rear calipers, then arch and sill rust before it gets 'critical'... only then will I properly start to look at the twiddly nice bits, so fully expect the new year, at the earliest.

The 3.7 diff will give more punch round town, but as I recall raises the revs a fair bit on motorway, yes? - this is, I assume, where the extra fuel consumption comes from you warn me about?  Thanks for the useful info

[omega2018]

Don`t forget that the knock control only retards the ignition not advances it

page 216 of the manual
"Octane requirement (RON)
95
98 <sup>(2)

(2)</sup> Knock control system automatically adjusts ignition timing according to type of fuel used (octane number)."

Note the ⁽²⁾ is next to 98 (super unleaded) not 95 (ordinary unleaded)

DBG pm me your email address I happen to have my manual in pdf format.

[Andy H]

Whereabouts is the knock sensor on the the V6?

One either side, about a third of the way back from front and halfway between head and sump. Bank 1 is down from cable tray to ecu loom and Bank 2 is just behind the alternator iirc

The knock sensors are just above the engine mounts in these pictures.

[Mr Gav]

Many thanks Mr Gav.. only retards it, then. And it's Dyno-only  Fair enough.

I was hoping that a Tech 2 would be able to give date, as it can with the trims (which I've now learned it totally unconnected!  )

If you want concrete evidence of what is happening with each fuel then you would need to dyno it, that's the only scientific way you`re going to get results.

As you say there`s the placebo effect to consider when doing your own test so they`re not really worth while.

A remap would probably make a worth while difference (and it already sounds like you`ve made your mind up  ) so get it done and enjoy it and forget about a couple of mpg difference, after all you don`t get a large saloon with a big V6 engine and worry about fuel consumption 

If you`re wanting a bit more go then the best single mod you can do is get a 3.7 ex plod diff, better acceleration through all the gears and not too much of a hit on mpg 

Haha, ta again.

I suppose you could say I've made my mind up, yes, but at the same time it's a long way off, yet. I really try and do things in an order, so the bodywork is still a state, but that all waits, as with various mechanical bits like the back wishbones I want to refurb, simultaneously doing the handbrake/rear calipers, then arch and sill rust before it gets 'critical'... only then will I properly start to look at the twiddly nice bits, so fully expect the new year, at the earliest.

The 3.7 diff will give more punch round town, but as I recall raises the revs a fair bit on motorway, yes? - this is, I assume, where the extra fuel consumption comes from you warn me about?  Thanks for the useful info

At motorway speeds the revs aren`t that much higher, around 250rpm IIRC but if you like to press on a bit then it`s worth the sacrifice 

[tigers_gonads]

The standard ratio for V6 manuals is the 3.7 and is higher geared than the standard V6 auto box which is a 3.9 so with a auto box, it will be slower off the line 
If you insist on keeping the slushbox, fit a 4.22 which will raise the revs at speed but improve pickup (and noise)

[Doctor Gollum]

Think the 2.5 is shorter than the 3.9 in the 3.0

[Diamond Black Geezer]

Certainly thinking a 'town diff' is on the cards... 

Thanks all.

[tigers_gonads]

Certainly thinking a 'town diff' is on the cards... 

Thanks all.

Piss take / banter aside for a minute J .......
Seriously mate, a thousand questions on various subjects and I and I suspect quite a few on here are wondering what you are trying to achieve with your car ?

Performance ?
Economy ?
Drivability ?
A mixture of all three ?

Just playing around / experimenting  and maybe wasting money ?

Just asking like 

[Diamond Black Geezer]

Fair point. and, again, joking aside, genuinely serious/sombre/sober...

I'm bored! That's the primary reason. I'm basically approaching the end with my job, we're planning a move down tot he midlands, Bekki's got in at Cov uni, but unless I can sort some work down there, ad well as all those other little things like somewhere to live, that sort of scuppers it.

I'm sat at this desk all day, with frankly little in the way of proper hard work - not like plenty of here do (present company included) I like to graft, get stuff done, not vegetate in front of a computer screen all day. The nature of the job has changed drastically in the last year or so. I'm no longer/not in the career path I wanted to be on (boo hoo, that'll change, I keep optimistic)

So, re: the above comp screen, my mind runs at a million miles a minute, 20% is devoted to my job, while the other 80% thinks about mainly car-related bits. Overthinking, looking for problems that aren't there. Also knowing, with more than a little frustration, that I don't get the time in the evenings to do half of what I want... the stuff I've spent all day thinking about. Notice that I basically never post on the evenings - too busy. All my posting occurs during mon-fri 9-5pm.

Like I say, it's overthinking, really. I appreciate your question, Steve. In lieu of actual work on my car, I think the theoretical work ends up becoming 'surrogate'.