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

Cue thread drift 'to spare or not to spare'

I do about 300 miles poodling along, but if I’m on the motorway and enjoying my self in the Plus Four, I look for petrol at 250 miles.

I know if patient I can 4l plus by filling v slowly

Well; coincidentally I had a problem with the fuel gauge in two-ton the past few weeks.
Always indicated completely full. He did that sometimes in the past, but after a while or a refill everything went back to normal.
But not anymore, Research was needed.
I found in this great forum that the cause could be the tank sensor and how to clean it.
The spare wheel and everything else off.
Disconnected the cables to the sender and the gauge gave zero.
Then the resistance measured on the sender, which gave 38 ohms which according to Bunny's data is about half full.
But how much is in the tank now?
It's pretty simple to figure that out on an old Morgan. No valve in the filler opening.
I took a cord with a thick nut on it and lower it to the bottom.
I could see that the tank was indeed half full. So the sender is ok.
The contacts of the sender and cables cleaned and reattached and everything worked as usual.
Refueled up to three quarters with the gauge on, and double check with the cord,everything fine.
Did 120 Km today and everything is back to normal.
Apparently it was just a bad contact. But to measure is to know as we say in Flemish.

What would we be doing all day without a Morgan!?!?

This thread seems to have drifted off the original topic which is how much fuel does the tank in the CX Plus Four hold. What the size of tank or MPG of a Plus 8 or Roadster may be is entirely irrelevant save for being further examples of how inaccurate fuel tank/mileage readings are in Morgans. This is a good question which one would imagine would be simple to answer. Sadly that is not the case. I will have to look back through some of my earlier posts on this subject but I seem to remember that the useable capacity of the tank is about eight litres less than the nominal size of the tank. In other words there are about eight litres of fuel in the tank that the fuel pickup cannot access. Depending upon how I drive I get between 30mpg and 50mpg so an average of 40 mpg. I fill up when I am approaching 200 miles on the odometer and would advise any other Plus Four user to do the same.

But not all! Have taken my Roadster down to "10 miles to Empty" with gauge just showing empty. It took nearly 50 litres. Close enough to spot on for a 52 litre tank.

As I've suggested before probably a Friday afternoon job

There are over 50 variations of trad Morgan fuel tank…

But I have measured a CX PLUS 4 tank at 43 ltrs…
The factory wanted me to make larger ones for the race cars

28 litres for 405 km. orange light was on

43 litres is over 9 gallons, which should last 360 miles at 40mpg. So you could wait for 300 miles before filling up.

Thats the big IF though Jon.
If there is in fact 43 litres in the tank and all those litres are accessible!

The reason I asked this question was because of a pending trip around Europe, it makes a big difference if you know you have 300 miles in the tank instead of 200 on a long journey.

Sir P