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

This from Almond in 2021 commenting on his Plus Four. Here he posted it in October 2021....

"I raised this same fuel gauge issue some time ago with MMC through my dealer. Their reply seems to be Morgan speak for 'put up with it'.

Amongst a number of problems with my Plus Four (now mostly sorted but some still ongoing) my comments on the fuel gauge were as follows

My comments " Fuel gauge and low level warning light calibration clearly needs some work. Last weekend the low level light came on when the gauge was reading exactly 50% full. Exactly 11 miles later when I stopped for fuel the gauge read 25%. I could then only get 26.75l of fuel in the tank. Needless to say both gauge and the warning light are currently close to no use and need sorting"

MMC's reply was, and I quote "The total amount of fuel that is USABLE in the tank is 33 litres. The actual gauge reading is 27litres From full to empty. There is 5 litres above the float when the tank reads full. This is why it takes a while for the gauge to start to read. Once it starts to read you have 27 litres left. The low fuel light comes on when there is 6 litres remaining. Once the gauge hits the bottom red the tank will only be able to take 33 litres. There is fuel in the bottom of the tank, but this is not useable".

It certainly wouldn't be acceptable on a normal car but in Morgan's view of the world it clearly is justifiable ...

So it looks like you have
- a 38 litre tank according to the Plus Four handbook.
- of that 38 litres only 33 litres are usable (according to Morrgan's reply to me).
- The sender is then calibrated to illuminate the level warning light when you have 6 litres of the 33 litres left.
- meaning you can only use about 27 litres before the light comes on.

That 27 litres correlates with my experience and I have only ever managed to get 28 litres in afetr teh light had been on for a bit. Currently if I am driving normally I aim for fuel every 250 miles. As Spanner Juggler indicates the odometer is still the best gauge in a Morgan.

On a more positive note fuel consumption is pretty good. Mine is an automatic and normally gives 42/44 mpg in mixed driving going with the traffic flow. Although a couple of weeks ago on the Isle of Man for the Motoring Festival it averaged 26 mpg on one tank in Sport+ mode on the unrestricted roads."

Thanks very much for this Richard.

Ties in with my findings and answers the question. Bit of a bugger really but, hey ho, it's a Morgan - what do you expect!

You are welcome and I wish you a great trip into Europe - we'll be waiting on some pictures

It does seem really crazy that the best any of us can say wrt any model Morgan is that 200 miles range for safety sake.. as you rightly say it's what we have bought into warts an all.. it's a good job they are a joy to drive

I would carry a spare canister as long as the tank capacity remains unclear.
Drive till the tank gets empty and use the spare petrol for the trip to the next fuel station. Fill up the tank.
The receipt will tell you the available tank volume. ( a bit of clever mathematical calculations on gas milage for the distance of dry tank to the petrol station can be added to get the perfect result )

Thanks for finding my earlier post Richard. I have been snowed under in the office and hadn't had chance to dig it out.

It strikes me that if SimonH is correct with the CX having an actual capacity of 43l, I have actually got 16l left in the tank when the gauge reads empty and the warning light is on (Never been able to get more than 27/28l in). Nice to know that Morgan are looking after me and want me always carry around that 16litres/12kg of fuel that I can't use in a light-weight sports car

Doesn't mean you can't use it, just you have to be confident about how far you can get on 16litres..... (I would have thought at least 100miles allowing for a bit of unusable volume at the bottom of the fuel pick up)

On older vehicles, you can alter (bend) the float arm to make the reading more accurate - not sure if possible with a more modern car.

You do have 6 litres available when the warning light comes on. That’s about 1.3 Imperial gallons, so presumably would get you another 40 miles or so….

The fuel pump wont actually pick up the last 16 litres......

Ah, that is shite.

Ian, it does seem damn crazy to be lugging this extra unusable amount around, hardly a selling feature and as Sir Percival has pointed out certainly limits the touring range unnecessarily