SV Fuel Tank Capacity

[BigCol]

The SV fuel tank is listed as 41 litres.  Not all of this is useable.  How much isn't?  

From memory (I have failed to search and find a definitive answer, hence this query) it's around 6l - so it's got a 35l capacity in reality.

Is that right?  

[Jonathan Kay]

Just had a quick look in the archives: it seems to be very variable with 6L at the low end of the range. (And on top of that there seem to be a lot of unreliable level indicators.)

How about filling it as usual (!)  and running it till it stops... with a tank ready in the boot?

Jonathan

[BigCol]

That, sort of, was my plan Jonathan.  I’ve installed a low fuel warning light I’d like to calibrate and was going to run to empty, add a gallon and adjust so the light was on at that level.

However, I need to use the car and do a half-decent length journey tomorrow so I filled it up ahead of that.  The fuel gauge was on empty and I tweaked the unit so the light was just coming on and it took 26l.

If the above is right, I’ve probably got about two gallons now between the low fuel light coming on and being unable to drive further.... 

[SM25T]

Yes ... 41 litres less 5 litres below pick up ... 36 litres usable. I can go well past the bottom of the gauge and still only get 30 litres in.

[Jonathan Kay]

I’ve installed a low fuel warning light I’d like to calibrate and was going to run to empty, add a gallon and adjust so the light was on at that level.

Piggybacked on the existing float and sender?

Jonathan

[BigCol]

The unit is a proprietary thing from eBay that fits in parallel with the fuel gauge/sender.  

I have also done a mod referenced elsewhere on here (adding 660ohms of resistance if I recall) which makes the full scale deflection of the gauge much more representative of the actual fuel level.

[Jonathan Kay]

Thanks

Jonathan

[Ant2]

On 17/04/2018 at 17:08, BigCol said:

The SV fuel tank is listed as 41 litres.  Not all of this is useable.  How much isn't?  

From memory (I have failed to search and find a definitive answer, hence this query) it's around 6l - so it's got a 35l capacity in reality.

Is that right?  

Did you work out how much past empty your car went?

I run mine till the bottom of the red portion of the guage but cannot get more than just over 24l in a 2020 420s.

Considering it's a 41l tank, it would sound like these floats are under cutting it by quite a lot?

Edited April 22 by Ant2

[Jonathan Kay]

I'm all in favour of thread resurrection. :  )

But have you read John Vine's exploration of fuel tanks?

 

 

Jonathan

[Ant2]

Thanks for those threads and I hadn't seen them.

It would appear the issues with the float arm would not occur on 2020s's as they have the newer sender,  the only possible issue that could occur  wasthat the float may be orientated incorrectly. but the only way to check that would be to remove the glued on carpet and remove the boot to check.

 

Has any one with a 2020 or newer SV got their fuel tank to take more than 24l once it hits the end of the empty guage?

Incidentally does the guage drop lower than the E (red zone) in to the white dotted section?

Sounds like I should have approx 10l of usable fuel once I hit near the end of the red zone, will see if the guage drops any lower and use the trip meter till I work out an average trip where I am filling atleast 30litres.

[BigCol]

As above… have modded my gauge with extra resistors to aid accuracy and when my third party low-level light comes on, I can put about 32 litres in.  So once lit, I have ~4 litres/30 miles before I get to the unusable bit (~36l of the 41l tank)

[Graham Hutton]

I got 28 litres in mine the other day at the bottom of the red bit and that is as low as I have risked going before!!

[Ant2]

3 hours ago, BigCol said:

As above… have modded my gauge with extra resistors to aid accuracy and when my third party low-level light comes on, I can put about 32 litres in.  So once lit, I have ~4 litres/30 miles before I get to the unusable bit (~36l of the 41l tank)

Is there much work required to put in the low level light and adjusting it accordingly? Is it something others could follow ?

[BigCol]

20 hours ago, Ant2 said:

Is there much work required to put in the low level light and adjusting it accordingly?

I suspect I used a unit similar to this (can’t see far enough back in my eBay purchase history to confirm).

Two wires simply piggy-back onto the gauge with the other two are for the LED which I mounted in line-of-sight on the dashboard.  There is a simple potentiometer that adjusts when the LED lights.