Talk Morgan Forums Morgan Sports Cars Morgan Plus Four, Supersport & Plus Six (CX & CXV Generation Vehicles) Fuel Tank size

So in reality the tank capacity is only approx 27 litres, or 6 gallons, which is very poor for continental touring

Is it possible to move the position of the fuel pump (drop it lower) so it picks up more fuel?

As I’ve said, I average 300 miles normal driving in my 2021 Plus Four, that’s 50 miles more than my old 1998 Plus 8, so after 250 miles driving abroad I start to look for petrol and never had any problems.

So from this we work out that the tank IS 43L.
If that you can suck about 30L of it through the pump installation.
As a result the chicken factor has been set using that point?

I’ve always managed 27 litres and no more from full tank to orange light going on. This seems to equate roughly to about 250 miles depending on how much I engage warp drive for the pops sound effect…😇
HB

I just picked up my new PlusFour. I am trawling through posts to pick up and learn “quirks” to work round.
I tested the dar at Williams and just after driving out the yellow low fuel light came on. I turned round just in case. I was told it was fine for the short test drive ( I had done a longer one in a manual a couple of weeks earlier) and had about 75 miles of fuel left. No problem there then!
So, until I have done a bit more mileage I’ll err on safety and keep the tank topped up. When I do mpg calculations I can use the odometer as a double check.
The handbook says 6l left when the light comes on so 6l = 75 miles? Hmmmmm.
I will do a tank measurement at some stage. I did that with the 1993 4/4 and confirmed the 55l capacity. I also drained and flushed the tank ( it had a drain plug), before putting 1gal in to see what the gauge showed on level ground. That was my absolute must add petrol limit.
The first job, though is to sort the filler cap out. Hard to remove. Tip from dealer was to file away a bit off the notches as others had done that. I recently found photos (JohnV6?) of orientation. I have a silicon spray to try as well.

Hi Sospan, whilst my Plus Six was in for the free 3 month service, I asked my dealer for clarification regarding the fuel tank capacity and the gauge readings, below was the answer from Morgan.
Presumably the same applies to the Plus Four. Hope this helps.
Nick


To give you some background information on the fuel tank:-
• The fuel tank can only hold 38.5 litres of fuel (38 litres is when the fuel pump clicks off for the first time, an an extra 5 litres can be added if you operate the fuel pump slowly).
• 33 litres in the tank is usable fuel (as measured from maximum fuel level to the very bottom of the gauge)
• 5.1 litres of fuel is above the maximum level of the float.
• The gauge measures a range of ~27 litres (5l above float, 5l below float, 1l ignored).
• The fuel gauge light therefore comes on when there is ~5.9 litres of usable fuel left.
• The M&S calibration ignores the very last measured point on the float (approximately 1 litre).
This is why the fuel gauge does not move for ages when the fuel tank is fully filled, but once the fuel level drops by 5l the gauge quickly starts moving.
So from the info you have put in the DSC case the car sounds correct.
Thanks Andy

Some strange figures there.
Max capacity 38.5l Pump first click is 38l so 0.5 l spare capacity. How can 5l be added? Think of 4 pint glasses plus a half pint glass for volume.
When I did a test drive the low fuel light came on as I left the dealer. I turned round to query it and was told 75 miles of fuel left.
For 40mpg that is 1.75gal or 7.9l.
For 38mpg that is 1.97gal or 9l.
For 42mpg that is 1.8gal or 8.1l
Who is right?
6l is 1.32gal so for 75 miles you need 56mpg!
So, what mpg are owners getting?
Anyone done a run out of fuel test and filled up to find actual capacity and range?
It looks like using the odometer to a suitable safety margin is a good idea when you have worked out your mpg.
Light on means fill up as a back-stop to your lets say 250 mile odometer reading.
It’s smacks of a bit like range anxiety in an EV. (But quicker and easier to find a top up p,ace).

I would strongly advise against running completely dry, modern submersible 'in tank' pumps are cooled by the fuel circulating - if allowed to run dry they burn out very quickly

The Boxster warning light comes on with 5L left in the tank and kindly asks me if I'd like directions to the nearest fuel station.
This is a car developed in the late 1990s...

Do keep up, Morgan.