General Petrol gauge / light

[Mercky]

I'm about to finish my first tank of petrol in my new TA, can anyone advise on actual gauge / warning light behaviour? The light has just come on and I have 2 segments left on the gauge, as far as I recall the Range said I had about 60 miles left. Can I safely run it down to when no segments are left? and / or down to zero range? I know there is a 5 litre reserve - is this from when the light comes on? I know this has been covered before but I couldent find a clear answer.

edit: sorry found a few threads!! https://www.fiatforum.com/500/314905-how-far-zero-fuel.html

 

[306maxi]

Very few people actually take enough notice to understand how it all works.

Let me explain and suggest that you promptly ignore any other responses other than Jrkitching's


The fuel light comes on at a certain level, for me this is usually minutes before I go down to the last 2 little segments (1/8th of a tank) and for me it usually comes on when I have exactly 77 miles to go (You got it at 60 miles which shows that it's triggered by a level and not a distance to go) but sometimes I've had more miles to go and occasionally less. This is triggered by the tank reaching a certain level.


Continue on and you should have an audible beep and a low fuel warning, if you had your range showing you will notice that it would have gone from showing anything from 35-31 and then goes blank, basically the car is saying that you have 30 miles to go now. Having run out of fuel I'd say you've probably got an extra litre or litre and a half after this, but really you should be pulling into a service station. As it is a range warning rather than a fuel level warning, the way you drive can affect what happens. For example, a few months ago I got home with about 45 miles range showing, next morning I got in and drove for about a mile and the range went blank, then just as I got to work the range showed 31.


More people will probably post stuff, they will most likely post crap, just saying

 

[lil.smartie]

Mine puts the light on at 36 miles range, stayed on 36 miles range until it beeped at 32 miles then went to dashes against range so pretty much the same but I did about 20 miles on that 36-32 range guess

Kate

 

[Most Easterly Pandas]

Very few people actually take enough notice to understand how it all works.

Let me explain and suggest that you promptly ignore any other responses other than Jrkitching's


The fuel light comes on at a certain level, for me this is usually minutes before I go down to the last 2 little segments (1/8th of a tank) and for me it usually comes on when I have exactly 77 miles to go (You got it at 60 miles which shows that it's triggered by a level and not a distance to go) but sometimes I've had more miles to go and occasionally less. This is triggered by the tank reaching a certain level.


Continue on and you should have an audible beep and a low fuel warning, if you had your range showing you will notice that it would have gone from showing anything from 35-31 and then goes blank, basically the car is saying that you have 30 miles to go now. Having run out of fuel I'd say you've probably got an extra litre or litre and a half after this, but really you should be pulling into a service station. As it is a range warning rather than a fuel level warning, the way you drive can affect what happens. For example, a few months ago I got home with about 45 miles range showing, next morning I got in and drove for about a mile and the range went blank, then just as I got to work the range showed 31.


More people will probably post stuff, they will most likely post crap, just saying

:yeahthat:

From experience of a range of Fiats, the 'reserve' has just been entered when the car starts beeping and showing the low fuel message (not the light) on the dash. Normally about a gallon, not sure what it is on the 500, although on my Bravo its 9L which is over 100 miles

 

[UFI]

on my Bravo its 9L which is over 100 miles

I can top that, in my Merc, the Fuel Gauge goes to empty with 25L left in the tank. That's potentially 250km of travelling blind. It's not a problem with my car, but a flaw with this particular model. I've now fitted a 99% accurate fuel counter than measures fuel used so I can run to empty, safely.

UFI will likely get one too.

 

[123barney]

Also bear in mind the crap you will suck up in older 500`s from the bottom of the tank, if done on a regular basis.

 

[Most Easterly Pandas]

I can top that, in my Merc, the Fuel Gauge goes to empty with 25L left in the tank. That's potentially 250km of travelling blind. It's not a problem with my car, but a flaw with this particular model. I've now fitted a 99% accurate fuel counter than measures fuel used so I can run to empty, safely.

UFI will likely get one too.

Whats this fuel counter which you speak of

Also bear in mind the crap you will suck up in older 500`s from the bottom of the tank, if done on a regular basis.

Ah this urban myth again. Fuel is sucked from the bottom of the tank regardless of if its full or empty

I also highly doubt you'll find any crap in the tank of a modern car if you've been filling it at proper forecourts.

 

[wellfan]

Also bear in mind the crap you will suck up in older 500`s from the bottom of the tank, if done on a regular basis.

I removed the tank on my ten year-old Mazda, over 130K on the clock, to replace the in-tank fuel pump. Thought I would take this opportunity to also clean out the tank. However, the tank was spotlessly clean.
So reckon this is a bit of a myth about the tank gathering crud.

 

[frupi]

I removed the tank on my ten year-old Mazda, over 130K on the clock, to replace the in-tank fuel pump. Thought I would take this opportunity to also clean out the tank. However, the tank was spotlessly clean.
So reckon this is a bit of a myth about the tank gathering crud.

Yep, as both you and MEP have pointed out, very much an urban myth on modern cars. I run both of my own cars from full to almost downright empty every single time, indeed I quite like seeing the orange light pop up, gives the car a bit of a 'disco' feel, plus I get to sit there with my bum nervously twitching and wondering just how many more miles I can squeeze out of the tank :devil:

One thing that many people forget is to actually change the fuel filter. Sadly an often forgotten service item when the car isn't taken to 'proper' mechanics for servicing. I change mine myself, that way, I know it's been done.

 

[UFI]

Whats this fuel counter which you speak of

I have an MPGuino that counts injector pulse duration, instead of extrapolating fuel use from the MAF like OE and OBDII gauges. If it says I've used 74l I know there's exactly 1l left. Boats and piston engined aircraft use the same principle I believe.

Yep, as both you and MEP have pointed out, very much an urban myth on modern cars.

One thing that many people forget is to actually change the fuel filter. Sadly an often forgotten service item when the car isn't taken to 'proper' mechanics for servicing. I change mine myself, that way, I know it's been done.

I believe this is another modern car myth. Many cars now have sealed for life in tank filters.

 

[frupi]

I believe this is another modern car myth. Many cars now have sealed for life in tank filters.

That may well be the case not that I've personally heard of 'sealed for life in tank filters', my second car does have a removable fuel filter which I change on an annual basis. So, tell me, because I'm genuinely interested, how does a 'sealed for life in tank filter' work? What happens if it gets blocked?

Follow up:

Yup, appears no doubt UFI, you are correct. Just looked on the MANN filter online catalogue and the fuel filter is a lifetime filter, which still begs the question, what happens if the 'lifetime filter' becomes blocked? I'm assuming it's a tank off job then?

My second car is a diesel and does have a fuel filter which on the last change I did, I noticed it was quite 'minging' inside!

 

[ahmett]

Very few people actually take enough notice to understand how it all works.

Let me explain and suggest that you promptly ignore any other responses other than Jrkitching's


The fuel light comes on at a certain level, for me this is usually minutes before I go down to the last 2 little segments (1/8th of a tank) and for me it usually comes on when I have exactly 77 miles to go (You got it at 60 miles which shows that it's triggered by a level and not a distance to go) but sometimes I've had more miles to go and occasionally less. This is triggered by the tank reaching a certain level.


Continue on and you should have an audible beep and a low fuel warning, if you had your range showing you will notice that it would have gone from showing anything from 35-31 and then goes blank, basically the car is saying that you have 30 miles to go now. Having run out of fuel I'd say you've probably got an extra litre or litre and a half after this, but really you should be pulling into a service station. As it is a range warning rather than a fuel level warning, the way you drive can affect what happens. For example, a few months ago I got home with about 45 miles range showing, next morning I got in and drove for about a mile and the range went blank, then just as I got to work the range showed 31.


More people will probably post stuff, they will most likely post crap, just saying

Don't forget maxi that after the beep and low fuel sign there is the further step where the fuel gauge goes completely blank instead of just one blip on the meter. That's when you should be going to the nearest petrol station = )

 

[123barney]

One thing that many people forget is to actually change the fuel filter. Sadly an often forgotten service item when the car isn't taken to 'proper' mechanics for servicing. I change mine myself, that way, I know it's been done.

--------------------------------------------------------------------------------------
So, if its an urban myth that tanks don't have dirt in them over a period of time, why fit a fuel filter, and change them in a "proper" service.


A lot of faith is given that fuel stations deliver 100% clean fuel, and I don't believe that to be the case, hence the standard fitting of a filter. IMO

 

[306maxi]

Well, no one is asking about filters, only about the trip computers. Only the multijet has a fuel filter that is a service item, dismal's will always have fuel filters because diesel is less refined as a fuel and to capture water. There may be a fuel filter in the 500's tank, but it's not a service item as fuel these days is good. Older petrol cars have fuel filters sometimes.

 

[jrkitching]

One thing that many people forget is to actually change the fuel filter. Sadly an often forgotten service item when the car isn't taken to 'proper' mechanics for servicing. I change mine myself, that way, I know it's been done.

--------------------------------------------------------------------------------------
So, if its an urban myth that tanks don't have dirt in them over a period of time, why fit a fuel filter, and change them in a "proper" service.


A lot of faith is given that fuel stations deliver 100% clean fuel, and I don't believe that to be the case, hence the standard fitting of a filter. IMO

I was one told that petrol stations have eight separate filters between the fuel in the main tanks and the nozzle. Excepting cases where mistakes are made and gross contamination occurs, fuel purchased at the pumps is unlikely to need filtering further.

The main contaminant of fuel in the car's tank is water, which condenses inside the tank from the atmosphere. In days past when fuel tanks were made of metal, this would collect at the bottom, corrode them from the inside & rust particles would collect in the fuel, hence the need for a filter to trap these particles before reaching the engine.

Modern tanks are almost always made of plastic, which doesn't corrode. Modern fuels contain ethanol (dreadful stuff), which will keep any water which forms in solution (water & ethanol are mutually soluble in each other). So fuel filters are largely unnecessary on current cars and often omitted.

One consequence of this is that you can't safely use fuels containing ethanol in fuel systems with unprotected metallic parts, as the absorbed water in the fuel will increase the rate of corrosion.

It's a problem for classic cars, and a big problem for anyone wanting to use mogas in light aircraft, as sources of ethanol-free fuel are getting almost impossible to find now.