Low Fuel and Cruising Range

[roks]

Hi All,

Just wanted to know if the cruising range gets to 0, does that mean it will be empty soon and car will stop?

I had a bit of a panic yesterday, had to go somewhere in a hurry, was low on petrol, started off with 5miles and eventually made it to the petrol station and read 0.

Is there a reserve after that point or have I used up the the reserve already?

Thanks

[mrpj]

I've never even run that low and fortunately never had a situation where it happens. I would suggest that the range display errs on the side of caution and there is more left in the tank than the figure indicates. 

 

[Catlover]

But who would want to test to see if there is fuel left 😀

It is not good generally to be running on a low fuel tank. Two reason 1) any debris in the tank will sink to the bottom, so when you low on fuel you may be drawing it into the fuel system.  2) in winter you likely to get more condensation (water) in an empty tank then when it is full of fuel.            
Just a thought.

[FROSTYBALLS]

When the low fuel ight comes on, you will have around 7.5 litres remaining.

[TonyHSD]

I had once to drive 30+ miles in negative, no damage or run out of fuel,  but the uncomfortable feeling is more than anything else, won’t recommend to anyone, plus the other risks above. 👍

[yossarian247]

My wife once drove my 2009 Auris 1.6 the 32 miles home from where she worked with the low fuel warning on all the way and the range showing zero miles. I wasn't best pleased as where we lived at the time was a further 6 miles from the nearest petrol station! Decided to risk it and drove to the petrol station without incident, where I brimmed the tank. From the amount it took to fill it I think it must've still had around 2-3 litres left in the tank at that point.

[mrpj]

I don't even look at the remaining distance function or the m.p.g. in the display but rely on the actual fuel gauge 1/4 tank on the gauge squirt some in!

[roks]

Thanks guy for your inputs, it wasn't deliberate, I think there was still fuel left as I drove a further about 500meters after 0 miles showed and didn't feel like its about to stop.

[MrZardoz]

23 hours ago, Catlover said:

Two reason 1) any debris in the tank will sink to the bottom, so when you low on fuel you may be drawing it into the fuel system.

Never understood this as the fuel is supplied from the bottom of the tank. Plus you've your fuel filter too before it gets to the engine.

[MrZardoz]

 I don't like driving close to empty as the 'block' display rather than a fuel level needle is a poor indicator of how much I have left.

 

[Catlover]

12 minutes ago, MrZardoz said:

Never understood this as the fuel is supplied from the bottom of the tank. Plus you've your fuel filter too before it gets to the engine.

So, it’s capable of blocking the fuel filter. That’s what filters are for, remove particles which should not be there.  But a blocked fuel filter will cause problems.

[MrZardoz]

I mean there's no greater risk of using fuel from the bottom of the tank as it's always delivered from the bottom of the tank.

The risk of being stranded because you've ran out of fuel is a big worry though 😄

[Mooly]

I learned something new last week relating to low fuel levels. I'd taken our old 1.4 Corolla around the Trough of Bowland and knew I was low on fuel but also knew there would still be plenty left when the low fuel light came on. A police incident meant the road I was going to use was closed and so I had to double back and head into Clitheroe at which point the low fuel light came on. I had around 30 to 35 miles to travel at this point and so continued  home.

About 4 miles from home I hit the first traffic lights, roundabouts etc and I was aware of a 'new noise' like a very low level continuous humming. Was it something behind me... no... it was coming from the Corolla. It wasn't loud but was continuous. When I got home I popped the bonnet and the noise was much more prominent but vague in where it was coming from. 

Twenty minutes later decided to go for petrol, it was still making the noise. Filled up (only got around 48 litres in and it hold 55) and the noise was gone.

I was going to ask on here but just looked it up first and apparently its a common effect when you are low on fuel, particularly if it is hot and the remaining fuel in the tank has got hot. That is on any make and model. So mystery solved and it is something I have never experienced  before in all the years.

My Auris has got as high as showing 476 miles cruising range when I fill up and is currently doing around 51mpg. The actual cruising figure should be closer to 600 miles based on the mpg... again it always errs on the side of caution.  

    

[Cyker]

Normally, running low on petrol is not a risk to the filters because, as mentioned, the fuel is sucked out from the bottom anyway. Any debris would be sucked in long before you get to a low fuel level. Actually, if anything, I imagine there is now more danger from *not* running petrol down to low levels, as all this ethanol they are putting in means the petrol soaks up more water which falls to the bottom of the tank as it is heavier. It's a known but rare issue in E10 countries where cars with E10 have sat for a long time - In extreme cases the water and ethanol separates from the petrol over time, and sits on the bottom for so long the bottom of the tank starts to rust, and then when the car is started a load of rusty water gets sucked into the fuel lines! Lovely! This is pretty rare tho', and requires an exceptional amount of negligence by the driver.

This is also why everyone recommends the use of a fuel stabilizer in cars that are going to be sat for a long time.

 

Diesel is another matter - I was told if you don't regularly fill your diesel tank to the brim, you can get condensation in the part of the tank above the level of the diesel. This drips into the tank and sits on top of the diesel, leaving a layer of water where microbes can grow; If that happens and you run the tank to empty, there is a good chance any such microbe clumps could get sucked into and block the filter.

It's not a big risk, esp. if the tank is regularly filled, and the cleaning additives in the better diesels tend to be quite hostile to the microbes anyway. It's only really if the tank is always half-filled, or is left to sit for ages that it becomes a danger.

 

Ironically, the solution to all these problems is drive the car more  This agitates the tank, stops things settling and keeps things flowing!

 

An interesting one is EV batteries -  You definitely don't want to run these low because, as the electrons drain out the bottom of the tank, you get dangerously close to the protons that normally sit on top to keep the electrons pressurised so they drain into the power cable faster, and if these get sucked into your power cables they will clog them up and all sorts of weird stuff starts to happen like the car's power flow reverses so forwards becomes backwards, the flux capacitors start inverting, the infotainment starts making farting noises etc.

 

[Roy124]

Of blocked filters and empty tanks:

One day we were driving from Strasbourg to Paris.  The car would not start and we had the bonnet up and checked the carburettor.  The chamber below the filter mesh was full of a rust red sediment.  It was probably the result of 80 octane fuel in Turkey.  We scooped it out as best we could and then reassembled the Stromberg carburettor.  The car ran but not very well.  Along came a Frenchman, stubble beard and wearing a suit.  He had no English and we had inadequate French.  He offered to help and quickly adjusted the carb and everything was fine.  He explained he was a BMW mechanic.

We refuelled with French petrol and set off for Paris.  No speed limits in those days and we ended up racing a BMW coupe with the hood down and a mademoiselle in the passenger seat blowing kisses at us (etc).  I think we averaged in the high 80s for the 300 mile journey and I guess 24 mpg.  We ran out of fuel in Paris - right on the top of a hill with a petrol station at the bottom!

[TonyHSD]

Running low on fuel is not ideal for the fuel pump, the noises Mooly had heard of might be exactly that and if left running long enough or repeating that event often the pump can burn out itself, yes will become charred and seize, no fuel will ignite though., I have seen pumps like that in the shop. Best to keep sufficient amount of fuel all the time, but in rare cases running low will not cause harm. The hybrid Toyotas are different story, leaving them without any petrol can kill the hv Battery and got you into big trouble. , without been able to start after refill. 

[Roy124]

You mention hybrids and not running out of Battery.  I just wonder what the Corolla Battery symbol is actually telling me.  At a guess each bar is 10%.  Mine never reaches the top -100%? or below half -50% before the ICE clicks in.  Assuming the Battery is at half and I then need a high power output the battery will still be able to augment the ICE.  In other words you don't run out of puff.

Is this cycling between 50% and 90%the norm?

[Catlover]

44 minutes ago, Roy124 said:

You mention hybrids and not running out of battery.  I just wonder what the Corolla battery symbol is actually telling me.  At a guess each bar is 10%.  Mine never reaches the top -100%? or below half -50% before the ICE clicks in.  Assuming the battery is at half and I then need a high power output the battery will still be able to augment the ICE.  In other words you don't run out of puff.

Is this cycling between 50% and 90%the norm?

But if you run out of petrol and you continue to use the HV power you are going to run out as there is no ice to kick in. That is unless the computer protects the HV Battery and the car sort of stops suddenly. I wouldn’t like to test that scenario when on a motorway. Once you HV Battery is empty I heard it is not the simple case put some fuel in and it will charge up. I been told it is more complex that that.

you last question, very very rarely has I seen all bars filled, going on a long downhill it done it, but I have never seen no bars.  Apparently it’s not good to fill a Battery not empty a battery. I heard the same applies with a mobile but there does not appear to be a protection on a mobile. You need to remember to charge to full or completely run don.

[DaddyBaddy]

For the clubs benefit (and for the interest of other Auris owners), tonight I ran my petrol down as low as I’d dare go. I had 5 miles range left, then the range indicator went to all dashes. - - - - 😳 Range anxiety!!

I had 2.5 miles to go to reach the safety of the petrol station 😬 Would I make it?….

I’m pleased to report that I made it to the petrol ⛽️ pump safely. Phew! 😰 

[mcntosh]

8 minutes ago, DaddyBaddy said:

For the clubs benefit (and for the interest of other Auris owners), tonight I ran my petrol down as low as I’d dare go. I had 5 miles range left, then the range indicator went to all dashes. - - - - 😳 Range anxiety!!

I had 2.5 miles to go to reach the safety of the petrol station 😬 Would I make it?….

I’m pleased to report that I made it to the petrol ⛽️ pump safely. Phew! 😰 

You’re a braver man than me!

[DaddyBaddy]

The low fuel warning light comes on quite late in my Auris (compared to my last car which was a 2010 Ford Focus Titanium 1.6 TDCI) which used to put the low fuel warning light on at 100 miles range left. Plenty of time to refuel. 
 

Now having owned my 2016 Auris Excel hybrid hatchback for 2.5 months, I’m working out the differences between to two cars. I’m not a chancer when it comes to fuel. It was purely for research purposes! Now when I see the Auris low fuel light come on, I’ll head for the pumps, and not push it onto fumes and volts. 👍🏻

[DaddyBaddy]

On 7/1/2021 at 9:57 AM, roks said:

Hi All,

Just wanted to know if the cruising range gets to 0, does that mean it will be empty soon and car will stop?

I had a bit of a panic yesterday, had to go somewhere in a hurry, was low on petrol, started off with 5miles and eventually made it to the petrol station and read 0.

Is there a reserve after that point or have I used up the the reserve already?

Thanks

 

I got 572 miles of range showing (when filled to the first click cut off at the petrol pump ⛽️)