Member Since: 11 May 2008
Location: UK
Posts: 6266
RDR wrote:
grzesiul Below 50%? I can why understand empty might cause issues (with cr&p and sludge?) but 50% seems a bit conservative unless Im misunderstanding your statement?
no no misunderstanding but due to how DPF operates and interacts with the car system in regards to recon process scheduling and all if recon is due and low fuel is also recognize by the car recon will not kick in and might damage it in worst case scenario I read....
G
29th Aug 2015 9:08 am
Robbie
Member Since: 05 Feb 2006
Location: ¯\_(ツ)_/¯
Posts: 17932
radders89 wrote:
Filled up yesterday with computer saying 5 miles until empty (I like to live dangerously) and it only took just over 73 litres. Defo a smaller tank than the D3.
The D4 tank is identical to the later D3s. Volume is as per handbook and there is no difference across MYs. Fuel system reserves around 4 litres for itself to avoid running dry. It does this by faking the symptoms of running out of fuel with a program in the PCM. To the driver it feels like the vehicle has run out, but without actually doing so with zero damage to the (rather expensive) fuel system.
The D4 fuel gauging is incredibly pessimistic, reading zero with many litres remaining in the tank. This is annoying but has been a 'feature' of the D4 since its inception. Replacing senders (as some dealers have done) does not help either. The issue is with the IPC and the resistance-to-fuel calculation it uses from the values provided by the fuel tank senders.
From memory I think the largest fill I have achieved is 74 litres with zero range remaining for the last few miles, with the fuel level showing empty for even longer. Even with the 4 litres or so reserved for the fuel system there would have been 6 or so litres remaining in the tank - best part of 50 miles.
Hope this helps.
Land Rover - Turning Drivers into Mechanics Since 1948
Member Since: 09 Feb 2014
Location: Truro
Posts: 2407
Cheers Robbie (as always ), I wanted to say thank you to you for the tip on changing the mpg readout to -5.5 with the IID tool, but couldn't find the original thread last night.
I have now used two tanks and after making the adjustment the fuel readout is now accurate to within about 0.2mpg, so fantastic!
Also seems I may as well not bother letting them fiddle with the fuel tank.Andy
29th Aug 2015 9:39 am
Robbie
Member Since: 05 Feb 2006
Location: ¯\_(ツ)_/¯
Posts: 17932
Thanks Andy. Yep, not worth your trouble letting the dealer messing with it.
One of the side effects of tweaking the mpg display to read correctly is that it makes the range to go display even more pessimistic as it is now using a less optimistic mpg as part of its calculations. The fuel level display remains unchanged. The very act of tweaking the mpg display also resets all range calculations to the super-pessimistic mode before it re-learns the true average mpg.
Land Rover - Turning Drivers into Mechanics Since 1948
Member Since: 11 May 2008
Location: UK
Posts: 6266
Fitzy73 do you have some tip or quick descr on ow to do it, might be first thing on my list of tuneups
G
29th Aug 2015 9:50 am
DG Site Moderator
Member Since: 12 Dec 2005
Location: The Gaff
Posts: 50944
grzesiul wrote:
RDR wrote:
grzesiul Below 50%? I can why understand empty might cause issues (with cr&p and sludge?) but 50% seems a bit conservative unless Im misunderstanding your statement?
no no misunderstanding but due to how DPF operates and interacts with the car system in regards to recon process scheduling and all if recon is due and low fuel is also recognize by the car recon will not kick in and might damage it in worst case scenario I read....
G
The DPF only requires enough fuel to run for 20 minutes so not sure why that needs to be 50% plus 21 year LR veteran > D2 GS 2003 > D3 S 2006 > D3 HSE 2009 > D4 HSE 2013 > D4 HSE 2015 > D5 HSE 2018 > DS HSE R-Dynamic P300e 2021
29th Aug 2015 10:01 am
Fitzy73
Member Since: 09 Feb 2014
Location: Truro
Posts: 2407
grzesiul wrote:
Fitzy73 do you have some tip or quick descr on ow to do it, might be first thing on my list of tuneups
G
From the main menu on the IID BT its:
Car config
Confirmed list
IPC - Instrument Pack
Trip Fuel Eco Adjust
My trip fuel eco adjust was set to something like +7, but following Robbie's advice making it -5.5 seems to have done the trick nicely!Andy
29th Aug 2015 10:24 am
Klinkhammer
Member Since: 02 Jul 2012
Location: Highlands
Posts: 266
Thanks for all your posts I can see that there is no point in taking this up with the dealer.
My D3 was a 09 plate and I once put in 83 litres when I thought I was about to run out whilst towing.I'm to old to know everything......
D4 Gone over to the Dark Side (D5)
D3 gone ...... But now want one for knocking about! Is this a form of insanity?
29th Aug 2015 10:28 am
Dave T
Member Since: 03 Jul 2009
Location: Glasgow
Posts: 6902
When mine was in for a service today I asked them about the inaccuracy in the mpg readout, what a struggle that was. First they couldn't understand how an app could give me mpg...FFS it ain't rocket science, divide distance by quantity....... But that won't take account of road conditions or wind..........
Needless to say nothing was done and they say LR don't know if any issues as there is no fault code! These are supposed to be the experts on our cars as well!
And then off course, they have to make comment "it has non LR discs and pads fitted"..........Joined the BMWX5 45e group
1994 Defender 90
2015 RRS Corris Grey/Black roof
2016 D4 Graphite Santorini Black
2012 D4 XS Orkney Grey
2005 D3 S Maya Gold
On Topix theres two figures for the D4 ....one is 86.3 litres the other 89 litres
For info... The later of these sizes is for Petrol engine versions only.LRs are a fond memory, apart from the maintenance.
1st Sep 2015 9:42 pm
radders89
Member Since: 30 Aug 2010
Location: West Sussex
Posts: 1051
Robbie wrote:
The D4 fuel gauging is incredibly pessimistic, reading zero with many litres remaining in the tank. This is annoying but has been a 'feature' of the D4 since its inception. Replacing senders (as some dealers have done) does not help either. The issue is with the IPC and the resistance-to-fuel calculation it uses from the values provided by the fuel tank senders.
From memory I think the largest fill I have achieved is 74 litres with zero range remaining for the last few miles, with the fuel level showing empty for even longer. Even with the 4 litres or so reserved for the fuel system there would have been 6 or so litres remaining in the tank - best part of 50 miles.
Hope this helps.
Cheers for that Robbie
Just for clarity then is the D4 fueling more pessimistic than the D3? The reason I ask is that when returning home to Sussex from Dumfries last week I filled the D4 up at a garage about 10miles closer to home than the one I usually use and the distance to empty was always the same as the actual distance to home. Yet in the D3 we always had plenty of fuel in hand. This is also taking into account the slight increase in mpg of the D4 over our D3.MY15 D4 SDV6 HSE Corris Grey - Gone
MY05 D3 TDV6 SE Zambezi silver Auto Alpaca leather - Gone
MY02' Seat Leon 1.6s Metallic Black cloth trim with a hint of mould
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), I wanted to say thank you to you for the tip on changing the mpg readout to -5.5 with the IID tool, but couldn't find the original thread last night.
