Fuel tank

CYL · 11-19-2015, 02:00 AM

Just wondering....

How accurate is "Range" for the fuel consumption in iDrive?

The iDrive showing that the fuel consumption is 12.4L/100km

It seems quite accurate as it took 30L to fill up the tank after travelling about 240km. (8L/km or 12.5L/100km)

But once filled up, the "Range" indicates in iDrive shows a 631km in "Range"
That means a full tank is 79 Litres...

Spec saying full tank is 60 Litres, I heard that there are always some fuel, 5L - 10L, left inside the tank even if the fuel gauge is pointing at "0", not sure if it is true.
May I ask if there is any further fuel left inside the tank when the fuel gauge is pointing at "0" on our car?
or
when iDrive says "last 30km", does it mean there are only 30km left for the fuel gauge to hit "0"? or it calculates every single drop of fuel inside the tank already?

I always top up my car to full tank and avoid having less than half tank since the fuel serves as coolant for the LPFP, but I am just curious to know.

AUSf22 · 11-19-2015, 02:47 AM

You can't be a serious with that question... the estimated range of your fuel tank is not the way to calculate the size of your tank

For example, if you drive on the freeway a lot then you will get a lot more kms per litre. City driving especially during traffic and spirited driving will increase the fuel consumption. Whatever the specs say the size of your fuel tank, is the size of the tank

PG · 11-19-2015, 04:52 AM

The average consumption is accurate. The rest not so much. Measured by logging all my fuel use for past 10thousand km. Average 9.6L on my car is about 9.56 on my phone app. You shouldn't be running fuel down that low because of possible deposits at the bottom (not sure how true that is these days)

CYL · 11-19-2015, 06:51 AM

Thanks.
I never get less than 1/4 tank. Usually top it back up when it's half full.

Also read that the fuel is also used to cool the low pressure fuel pump.

Mayuri Krab · 11-19-2015, 09:03 AM

I've pretty much almost always ran my car till empty (once I drive said I had --- range left), due to the fact I drive 500-600km per week (which equates to about a tank per week) no issues with lfp yet.

My skyline had a fuel pump die. But the unit was already over 10 years old when it happened, so more wear and tear through aging rather than caused by running low I reckon.

MightyMouseTech · 11-19-2015, 09:09 AM

The "range" is based on your previous 50 km of driving. It will continuously change as you drive.

plazski · 11-20-2015, 01:08 AM

The range that is shown on the Idrive is till empty, not till the reverse. It is measured based on your last 30-50km of driving. It is pretty accurate. I usually fill up when I'm just under a quarter, at that stage it says around 100km left, the fuel nozzle clicks at around 53-54L meaning I have around 7L left. My average consumption on the Idrive is 6.9L/100km, so I guess you can say it's accurate.

11-19-2015, 02:00 AM	#1
CYL Major 129 Rep 1,382 Posts Drives: E92 Join Date: Aug 2013 Location: Australia iTrader: (0)	Fuel tank Just wondering.... How accurate is "Range" for the fuel consumption in iDrive? The iDrive showing that the fuel consumption is 12.4L/100km It seems quite accurate as it took 30L to fill up the tank after travelling about 240km. (8L/km or 12.5L/100km) But once filled up, the "Range" indicates in iDrive shows a 631km in "Range" That means a full tank is 79 Litres... Spec saying full tank is 60 Litres, I heard that there are always some fuel, 5L - 10L, left inside the tank even if the fuel gauge is pointing at "0", not sure if it is true. May I ask if there is any further fuel left inside the tank when the fuel gauge is pointing at "0" on our car? or when iDrive says "last 30km", does it mean there are only 30km left for the fuel gauge to hit "0"? or it calculates every single drop of fuel inside the tank already? I always top up my car to full tank and avoid having less than half tank since the fuel serves as coolant for the LPFP, but I am just curious to know.
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11-19-2015, 02:47 AM	#2
AUSf22 Lieutenant Colonel 2690 Rep 1,977 Posts Drives: 2020 M2C HS & Ferrari Roma Join Date: Sep 2014 Location: Sydney, Australia iTrader: (0) Garage List 2020 M2 Competition [9.83]	You can't be a serious with that question... the estimated range of your fuel tank is not the way to calculate the size of your tank For example, if you drive on the freeway a lot then you will get a lot more kms per litre. City driving especially during traffic and spirited driving will increase the fuel consumption. Whatever the specs say the size of your fuel tank, is the size of the tank __________________ 2020 M2 Competition \| Hockenheim Silver \| 437M Wheels / 763M Wheels \| RHD \| 2NH Brakes OEM M2 CS Steering Wheel \| MP Carbon Steering Wheel Trim \| MP Pedals \| MP Dash \| MP Interior Kit OEM M2 CS Bonnet \| M Performance Coilovers \| MP Rear Spoiler \| MP Rear Diffuser\| Perl Carbon Front Lip \| Remus Race Exhaust
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11-19-2015, 04:52 AM	#3
PG Second Lieutenant 41 Rep 244 Posts Drives: 2008 135i Join Date: May 2015 Location: Sydney iTrader: (0)	The average consumption is accurate. The rest not so much. Measured by logging all my fuel use for past 10thousand km. Average 9.6L on my car is about 9.56 on my phone app. You shouldn't be running fuel down that low because of possible deposits at the bottom (not sure how true that is these days)
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11-19-2015, 06:51 AM	#4
CYL Major 129 Rep 1,382 Posts Drives: E92 Join Date: Aug 2013 Location: Australia iTrader: (0)	Thanks. I never get less than 1/4 tank. Usually top it back up when it's half full. Also read that the fuel is also used to cool the low pressure fuel pump.
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11-19-2015, 09:03 AM	#5
Mayuri Krab The Cheap Arse Asian 47 Rep 585 Posts Drives: E90 335i & R33 Skyline GTS-T Join Date: Jun 2013 Location: Perth, Australia iTrader: (0)	I've pretty much almost always ran my car till empty (once I drive said I had --- range left), due to the fact I drive 500-600km per week (which equates to about a tank per week) no issues with lfp yet. My skyline had a fuel pump die. But the unit was already over 10 years old when it happened, so more wear and tear through aging rather than caused by running low I reckon.
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11-19-2015, 09:09 AM	#6
MightyMouseTech Major General 4338 Rep 6,196 Posts Drives: 13 135i 6MT LeMans Blue MSport Join Date: Feb 2013 Location: Ottawa, Canada iTrader: (0)	The "range" is based on your previous 50 km of driving. It will continuously change as you drive.
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11-20-2015, 01:08 AM	#7
plazski First Lieutenant 42 Rep 310 Posts Drives: 320d E90 LCI Join Date: Aug 2015 Location: Melbourne, Australia iTrader: (0)	The range that is shown on the Idrive is till empty, not till the reverse. It is measured based on your last 30-50km of driving. It is pretty accurate. I usually fill up when I'm just under a quarter, at that stage it says around 100km left, the fuel nozzle clicks at around 53-54L meaning I have around 7L left. My average consumption on the Idrive is 6.9L/100km, so I guess you can say it's accurate.
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