Petrol Gauge

[mrs.smith2012]

How do you guys keep track of your petrol… i.e. when you need to top up?

I am aware that the petrol gauges are notoriously unreliable on the Minors.. in fact Nell’s doesn’t seem to move further than the halfway mark, no matter how much I put in her.

I’ve just been logging my millage everytime I top up and estimating how many miles I’ll get before next top up. I’m allowing about 35miles to the gallon at the moment as she’s a 1275 engine and I’m doing lots of short journeys as opposed to long runs… does that seem sensible? Currently my calculations show me I should have another 40miles to go… yet the gauge was almost on empty today

So do I go by my calculation or the gauge? Is there any kind of upgrade you can add to the fuel tank so you can read millage a little more accurately? I don’t want to unnecessarily keep putting fuel in her… but I also don’t want to run out at an inconvenient point!

[Bill_qaz]

My gauge seems quite accurate, I run it until just above empty, then fill up. Judging by fill up its reasonably accurate.
Does your read full when full.
You could take a fuel can with you and drive until it runs out and see where the gauge reads when empty.

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[svenedin]

Mine seems OK too. You just have to be more aware of the fuel level as there is no low fuel warning light!

Stephen

[mrs.smith2012]

Aah okay,
When I got her she was showing just above empty…. I filled her up, at least I kept filling until the pump clicked off… I think it was just shy of £40.. yet when I started her up the gauge was showing on half. It stayed on half for well over a week and didn’t move and I’ve topped up twice more, gauge hasn’t moved. It just wobbles… so I started recording millage instead. It’s only today it’s dropped to almost empty, even though technically I should have another 40 miles left?
Is this normal gauge behaviour or do I need to take a look at this?

[svenedin]

No it's not normal fuel gauge behaviour.

Stephen

[mrs.smith2012]

No it's not normal fuel gauge behaviour.

Stephen

Oh dear.. naughty Nell. Okay. I’ll perhaps fill her right up again next week and see if the gauge will go past the half. Perhaps she wasn’t fully filled last time, although the pump did click off.
Failing that, that will be a little job for me to look into

Thanks for confirming!

[Bill_qaz]

I find, you do have to fill quite slowly, the pumps will click before full. When it clicks give it a few seconds and try again.

[mrs.smith2012]

I find, you do have to fill quite slowly, the pumps will click before full. When it clicks give it a few seconds and try again.

Yes perhaps there was an airlock or something?

Talking of fuel, a friend of mine said he won’t put supermarket fuel in his classic as it doesn’t do them much good. He will always fill up at a BP or something similar. Is there much truth in this?
Reason I ask is because it’s much easier for me right now to fill up at my local supermarket (I use their premium fuel) as my nearest BP means driving on a very busy dual carriageway and I’m not quite confident enough yet!
Will it do Nell any harm though?

[Bill_qaz]

Just go for E5 which is lower ethanol upto 5%. Personally I don't bother about the brand, although BP is nearest to the storage so gets more of that than other brands.
Mines 1098 engine but has been fitted with a cylinder head for unleaded fuel.
Your is 1275 engine I believe Phil is the best to ask if your engine is ok on unleaded or needs an addative.

[mrs.smith2012]

Oh she’s definitely fine for unleaded, I did check with the previous keeper, and I always top up with E5, I just wasn’t sure how important the brand was. As long as it won’t do her harm I’ll just fill up at Tesco til I’m brave enough to drive her up to the BP

[Bill_qaz]

Any petrol is better than none
Your confidence will soon grow Lets hope the rain eases up so we can all enjoy our moggies out and about.

[mike1864]

Gauges can read slightly over Full, or under Empty. But should be reasonably accurate in between the two extremes. So you have a fault.
For the benefit of a Newbie...
There are two main parts to the fuel display, either of which can go wrong.
In the top of the petrol tank is the Sender, which comprises a float on the end of a hinged arm. The change in the angle of the arm varies the resistance that this assembly presents to the display. The float may have a hole in it; so no longer floating. Or the variable resistor may have a fault.
The actual gauge measures and displays the current the Sender presents. This itself may have developed an internal fault (broken or shorting wire).
There are (at least) two different types; one is designed with the resistance going up as the tank empties, the other has it going down.
Others may advise which type you have, depending on your year.
I wouldn't suggest a newbie investigates this. Sparks and an open topped fuel tank don't mix .
Perhaps a local member can help? Or back to your auto-electrician (preferably one aged over 60, who won't waste time looking for somewhere to plug in his laptop ).

[mrs.smith2012]

I filled her right up yesterday, went slowly and kept going til I was over 26 litres. Gauge is showing full! So it does move. Perhaps I just didn’t fill her up enough last time. Still monitoring my millage so I can check it tallies with the gauge… let’s see how we go.

Confidence is slowly growing… I still get a bit anxious prior to a drive but I’m generally fine when I’m driving.. it’s just the thought of it, as silly as that sounds!

Can’t wait for the nicer weather though, might see some more classics out on the road soon!

Plus I want to take her to some local shows!

[mrs.smith2012]

Gauges can read slightly over Full, or under Empty. But should be reasonably accurate in between the two extremes. So you have a fault.
For the benefit of a Newbie...
There are two main parts to the fuel display, either of which can go wrong.
In the top of the petrol tank is the Sender, which comprises a float on the end of a hinged arm. The change in the angle of the arm varies the resistance that this assembly presents to the display. The float may have a hole in it; so no longer floating. Or the variable resistor may have a fault.
The actual gauge measures and displays the current the Sender presents. This itself may have developed an internal fault (broken or shorting wire).
There are (at least) two different types; one is designed with the resistance going up as the tank empties, the other has it going down.
Others may advise which type you have, depending on your year.
I wouldn't suggest a newbie investigates this. Sparks and an open topped fuel tank don't mix .
Perhaps a local member can help? Or back to your auto-electrician (preferably one aged over 60, who won't waste time looking for somewhere to plug in his laptop ).

Thank you for this… I’ll monitor the gauge behaviour but I think it’s a wiring thing I have a guy… I won’t mess about with wires.. good advice there! I don’t think he’s over 60 but he’s old school.. specialises in classics, a rare one!

[mike1864]

I filled her right up yesterday, went slowly and kept going til I was over 26 litres. Gauge is showing full! So it does move. Perhaps I just didn’t fill her up enough last time. Still monitoring my millage so I can check it tallies with the gauge… let’s see how we go.

Confidence is slowly growing… I still get a bit anxious prior to a drive but I’m generally fine when I’m driving.. it’s just the thought of it, as silly as that sounds!

Can’t wait for the nicer weather though, might see some more classics out on the road soon!

Plus I want to take her to some local shows!

Looks like it's working fine after all. 26 litres was pushing your luck a bit
The gauges are not completely linear, but you'll gradually learn whether "half" is really exactly half. And bear in mind that being on a slope (up/down/sideways) may give a slightly different reading. All part of the fun!

[Bill_qaz]

I filled her right up yesterday, went slowly and kept going til I was over 26 litres. Gauge is showing full! So it does move. Perhaps I just didn’t fill her up enough last time. Still monitoring my millage so I can check it tallies with the gauge… let’s see how we go.

Confidence is slowly growing… I still get a bit anxious prior to a drive but I’m generally fine when I’m driving.. it’s just the thought of it, as silly as that sounds!

Can’t wait for the nicer weather though, might see some more classics out on the road soon!

Plus I want to take her to some local shows!

29 litres/6.5 gallons is the standard tank size so you probably had approx 2-3 ltr left in tank, so you were almost empty.
Did you note what the gauge was reading?
I would suggest thats about as low as you want it to go, before refuel.
Refill again at 150mls and see what it takes, to give you an idea of its range.

[mrs.smith2012]

Thanks both, yes I think I had just over 2 litres left in her according to my millage ‘calculations’ although I did overestimate a bit so probably had a little bit more. Gauge was hovering just above empty so it was correct, although the drop was very sudden… went from half to empty overnight. Will still keep note of millage so I have some heads up of when I’ll start running low, but at least the gauge seems to be working as well as can be expected!

[Bill_qaz]

I think the problem is we get used to modern cars.
My modernish shows low fuel warning
Then refill warning.
While giving a countdown of how many miles of fuel remain, which constantly updates depending on driving style.
A shift indicator tells you when to change gear up or down
An economy meter tells you whether your driving good(green) or bad(red)

My minor fuel gauge varies if its on a slope, the needle moves if you go too fast around the roundabout. So I just refill when it get to 1/4 tank and enjoy the smiles per gallon and forget the mpg

[mrs.smith2012]

Haha I’ll do that! Thanks!

[ManyMinors]

To be fair, you can't expect such old cars to have very accurate gauges. The petrol gauge in those early cars do a reasonable job but they were old fashioned and basic even at the time. In 1964 - which is still over 60 years ago(!) the gauges were updated to the black faced instrument and fitted with a voltage stabiliser. This gave a slower needle movement and greater accuracy and were considered quite an improvement but it's all about getting used to the car isn't it. As others have suggested, make a not of the mileage when you fill up and you'll soon get to know what the car will cover on a tankful. You'll get used to it
I've driven Morris Minors for well over 50 years and have never run out of fuel yet. They have a relatively small tank by today's standards and with fewer petrol stations around, you do have to keep an eye open on longer journeys.