When my car gets to empty (or saying 20 miles range on the dash) I fill up and the most fuel I can put in the car is 84 litres, I never get to 100l. I have owned the car since December and this has always been the case. What is going wrong here as specs say the car has a 104L tank?

Many thanks

Tom

When it gets to zero, it isn’t actually zero. I’ve gone 30 miles beyond zero before, and still only put in 98 litres. Although I thought the tank was 98.5 litres but maybe there was a change for 2011

Hi, not sure that this will answer your question fully other than it may be that there’s a bigger “reserve” than one might think;



I have a 3.6 and although not as short as you on an “empty - full” fill up it’s never much above low 90’s.

Jon

The tank should never be run dry and the reserve is there to save the fuel system sucking up air or sediment. If it's a 4.4 the DPF regeneration doesn't work with less than 1/4 tank so it's never a good idea to run theses cars with less than that in the tank. 2012 TDV8 Vogue (L322)

L322UNLIMITED wrote:

When my car gets to empty (or saying 20 miles range on the dash) I fill up and the most fuel I can put in the car is 84 litres, I never get to 100l. I have owned the car since December and this has always been the case. What is going wrong here as specs say the car has a 104L tank?

Many thanks

Tom

After 12 years theres going to be all sorts of crap in the bottom of the tank, I rarely go less than 1/4 tank except on a long run, I think most I've ever put in in one go was about 95l on a trip to Thurso.

Would not recommend going below empty on the gauge. Fuji White / Jet 2012 4.4 TDV8 Westminster

The input to the fuel pump sits on the bottom of the tank, so will pick up regular fuel sediment / water present in the tank whether you run it low or not. Fuel sediment is also stirred up all the time due to the vehicle's movement, so will be sucked up constantly and filtered by the fuel filter in the engine compartment.

Any water present is, of course, intercepted by the water trap. Rust isn't an issue as it was with older cars; as the L322 has a plastic tank. So unless there's sand / gravel / dirt in your tank, running low won't be an issue from a sediment / debris point of view. Even then it's likely to be trapped in the input filter to the fuel pump and not cause any harm unless there's lots of it!

Running very low is still bad though, as it can cause air ingestion to the high pressure pump and injectors. It can also cause the fuel pump to run hot, leading to premature failure as the pump is cooled by the fuel around it in it's surrounding reservoir.

As stated above, DPF regeneration appears to check fuel quantity before triggering a regen, that's certainly been discussed on this forum before. However, I seem to remember reading somewhere else that this isn't actually the case!

Regarding the OP's question - I'd say the fuel gauge sender is reading just a tad low. At 20 miles range, I'd expect there to be around 15L in the tank, which given the tank's capacity + 5L for the filler neck, would lead to being able to get 90+ L in there when remaining range is stated as 20 miles. It's just a case of getting to know your gauge really. Every car is different!

Jon 1992 RR Classic 3.9 efi Vogue
2014 Disco 4 HSE
===================
Both my fatties now gone...
Previous: 2011 L322 4.4 TDV8 Vogue SE /// 2002 L322 4.4 V8 HSE /// 2009 Discovery 3 2.7 TDV6 XS /// 2004 Defender 90 TD5 /// 1993 110 V8 Snatch Landrover /// 2005 Discovery 3 2.7 TDV6 SE (Aus) /// 1990 110 Isuzu 3.9 County (Aus) /// 1976 Series III Trayback (Aus)

excellent answer Jon...  ... - .- -.




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Thanks Stan!  1992 RR Classic 3.9 efi Vogue
2014 Disco 4 HSE
===================
Both my fatties now gone...
Previous: 2011 L322 4.4 TDV8 Vogue SE /// 2002 L322 4.4 V8 HSE /// 2009 Discovery 3 2.7 TDV6 XS /// 2004 Defender 90 TD5 /// 1993 110 V8 Snatch Landrover /// 2005 Discovery 3 2.7 TDV6 SE (Aus) /// 1990 110 Isuzu 3.9 County (Aus) /// 1976 Series III Trayback (Aus)

That makes sense now I think about it. My guage over reads the how much is in there and I have on occasion been able to get over 90 L in there. I think on earlier cars there is an option in the GAP IID tool to recalibrate the fuel guage but unless it's in teh full and untested list I haven't found it and if it is I don't want to mess it up by trying. 2012 TDV8 Vogue (L322)

I'm never sure why people think there will be sediment in a fuel tank. The simple act of driving sloshes fuel all over the tank internally, so you're always sucking up thoroughly mixed fuel and any small particles get mixed up with it and then filtered out in the fuel filter. Drives:
2010 FFRR TdV8 Vogue - Stornoway Grey
2010 FFRR TdV8 Vogue SE - Zermatt Silver
1998 BMW E36 M3 GTII

Maybe just a useful scare story to stop people running their tanks too low and causing damage by not so scary sounding means - air in the fuel doesn't as bad as sand in the fuel. 2012 TDV8 Vogue (L322)