To have run the petrol down to 40 miles left

[Baby3or]

I recently drove 115 miles on a motorway back to London suburbs. I was watching the petrol number the whole way (it gives it in miles left to go before it’s empty) and at 70 I was considering stopping for petrol (lots of places on the motorway and then lots of places in city suburbs on the way to our house). I decided not to stop as baby was asleep and also our older child was keen to get home after a long journey.

we live less than a mile from a big supermarket with a petrol station and also plenty of other places to fill up.

husband had a go at me saying ‘what would I have done if we had run out of petrol / how had I let myself get in that situation’ I said I was fully aware how much was left and I made a decision not to refuel as on balance it was low but not empty.

AIBU??

Yanbu. I’ve had 2 bars before and no idea of how many miles were actually left and did think I was cutting it fine but 40 miles is plenty. Also if you did actually run out of petrol what is the absolute worst case scenario? It’s not like it’s the middle of winter or you are in the middle of the desert or something.

I used to ride motorbikes, and not all have a petrol gauge. I learned to tell when I was running out by the feel and sound of the engine, and could switch the tank to reserve whilst I was on the move. Fun on the motorway.

I fill up when mine bleeps to say it's reached 25 miles left!

You need to know your car to be able to do this safely.My Citroen went straight from 20 miles left to running out of fuel.

your dad sounds like my friend...
"have you got a jerry can?
"Yes"
"Has it got petrol in it?"
Emmm 😆

40 miles is fine, I often set out of get DD from school 15 miles away with 40 miles left and fill up in the town where her school is.

Sorry but running your tank down as low as some posters are claiming, is not clever or something to be proud of, as when your car starts getting down to the dregs of the fuel tank, it can pull up all sorts of shit into the engine, which in the long term can do damage to your fuel pump, filter, and catalytic converter. I was told this by my mechanic son in law, so never let mine get down too low. I also wouldn't let it get down to just a couple of miles or zero, in case I needed to get someone to the hospital in a hurry, and then ended up breaking down because I didn't have enough fuel to get there. Come on ladies, I thought we were cleverer than this! However, I don't think the 40 miles the OP had left, was anything to worry about.

Diesel tanks get sludge in the bottom so you shouldn't run them down too much as the sludge gets forced into the engine 🤓

Yep I get to this point regularly! When the light is flashing I do tend to head to the nearest petrol station (though I still reckon I have 20 miles or so in the tank).
I've run out of fuel in two of my previous cars and you know what? The world didn't end! I called the RAC out and they put enough fuel in to get me to the station. Another time a friend came to my aid. It's no big deal. 🤷🏻‍♀️

Is this an old wives tale or is it true?

I am a big shocked at everyone letting their cars run so low. You are travelling with two small children. I would not want to be stranded on a motorway with them. If there was an accident up ahead your petrol could run down just queuing in a tail back. My dh does this. Living by the seat of his pants and it drives me crazy. If he had done it on a motorway with our kids when they were small l would have been upset. Motorway driving eats petrol so it's my first thought before l enter one..have l sufficient fuel. And l have been told since my early days of driving that it is not good for the car.

My old car used to do this but not quite so extreme. The fuel light would come on then I would drive a couple of miles and lose 10 miles to empty then it would do it again a couple of miles later, perhaps stabilising for a few more before doing it again. I didn’t leave the car to go much past 1/4 full ss I really didn’t trust how much fuel there was. I also didn’t want to run on fumes as this can damage the engine.

I mentioned running out recently in an unfamiliar hire car upthread and that was a Citroën, which did just that.

It also failed my 'if I'm 40 miles or closer to home when the light comes on, I'll get home without filling up' rule that no other car in decades has let me down on.

But normally, 40 miles is loads if you've only got 15 miles to go and I'd be more annoyed if a partner bought fuel on the motorway at those prices than the non existent risk of running out. If you get stuck in traffic you can always fill up but otherwise not needed.

The number of people proudly declaring their stupidity on this thread is hilarious.

https://www.capitalone.com/cars/learn/finding-the-right-car/3-reasons-why-you-shouldnt-run-your-cars-gas-tank-to-almost-empty/2456

Many posters need to read.this.

Mine goes down in increments of 5 miles. I don't even consider filling up until the reminder/warning light comes on which is 50 miles iirc. I have let it go to 5 before but usually I would do it at about 25. (Assuming just short local journeys, not motorways)
Motorway service stations are usually more expensive so I would avoid using one if I was confident I'd get to a different petrol station well before running out.

However I'm not convinced that the petrol incident is the real problem in OPs case.

Grey rock his stupidity. And consider your exit.

Why was leaving worse? And how long did you leave for?

It took me 3 weeks to realise I was happy alone.

I did exactly the same on Sunday, drove from Devon to Surrey, had 40 miles left on the screen. And? I normally fill up at a 1/4 of a tank, so this was unusual to go that low. I didn't even mention it to Dh, because it didn't need mentioning. But the problem is what exactly? The next day I drove straight to petrol.

How does the car actually know how much fuel is in the car?

If there is a sensor that detects the level, does it float? Is it part of the petrol tank?

If you have a tank full of fuel, how would you actually measure how much fuel there is left in it?

Well if only Google existed

How Fuel Gauges Work | HowStuffWorks

A float that has a variable resistor on it - so the rod goes up and down, but may eventually not be able to go down to much once the tank is almost empty.

XenoBitch · Today 00:00

I used to ride motorbikes, and not all have a petrol gauge. I learned to tell when I was running out by the feel and sound of the engine, and could switch the tank to reserve whilst I was on the move.

Likewise, my 600 Eliminator did 85 miles exactly, before reserve and I always zeroed the odometer, before a long trip. I'd be getting twitchy at 84 miles and ready to turn the tap.

I have a friend who runs the fuel down to less than 10. Lady time I got a lift with him he filled up with 4 miles left! It was a nail biting journey!

Having just watched a couple of YouTube videos, I wonder how reliable the "miles left" is below a certain level.

It might have more. It might have less. But I am not sure if it actually knows the true level of fuel left and of course, your MPG might vary.

A gallon is 4.5 litres. My car does 70 MPG - so 16 miles per litre. A litre of fuel in a fuel tank is going to have a very low depth in a fuel tank - it's 1000 cm*3 so I'd be sceptical about the accuracy of a gauge - and be concerned that it would have the dregs in the bottom of a fuel tank.

See I don't really intentionally let mine get really low. My old car had no gadgets so had the steady light when getting towards low and the blinking light. When the blinking light came on I knew I had about 35 miles and I would fill up. And I would remember because the light blinked at me the full journey.

My current car goes bingley bong and then won't remind me again until I'm running on fumes. But my brain forgets instantly without the constant visual reminder.

I have run out of fuel - ie the car stopped because it had no petrol - twice.

The perils of having no money and having to get somewhere by car.

It actually wasn't something I want to do again but it was inconvenient and stressful, not life threatening, either to me or the people around me.

I don't like the posts calling people stupid, we are all human and sometimes we make mistakes. As mistakes go, getting low on fuel is pretty harmless.