Fuel Gauge And Range Indicater

[JoBaxi]

Hi there,

bought used avensis D4D today, and on the way home. fuel light comes on. thats no problems, and i was in my home town by now. But the thing that worried me, by looking at the fuel gauge, i would have thought maybe 1.5 gallons of fuel left in there. maybe a tad more, but the range indictarer was saying 112miles...

now, i dont really plan to let the fuel gauge ever come that low that the light will come on. (diesel cars, i like to keep a bit of fuel in the tank). but which one to i believe if i ever have to rely on one or the other?

Thanks.

[igormus]

Hi there,

bought used avensis D4D today, and on the way home. fuel light comes on. thats no problems, and i was in my home town by now. But the thing that worried me, by looking at the fuel gauge, i would have thought maybe 1.5 gallons of fuel left in there. maybe a tad more, but the range indictarer was saying 112miles...

now, i dont really plan to let the fuel gauge ever come that low that the light will come on. (diesel cars, i like to keep a bit of fuel in the tank). but which one to i believe if i ever have to rely on one or the other?

Thanks.

hello mate

even i own petrol one -- i normally keep an eye on the tank gauge readings because it is the first indicator. the computer is second one.

cheers/Igor

[JoBaxi]

thanks for your reply.

so gauge is the one to rely on. i dont plan on letting the car ever run on minimal fuel in the tank, but i was just worried that the computer myt be messed up, but then again fuel gauge tends to move when "spirited driving on B roads"....

have u ever let your gauge go all the way to the bottom n just relied on the computer? am not suggesting to do that, but thats a big no no in a diesel, as opposed to petrol where u just stik summore petrol in if u run out.

[igormus]

thanks for your reply.

so gauge is the one to rely on. i dont plan on letting the car ever run on minimal fuel in the tank, but i was just worried that the computer myt be messed up, but then again fuel gauge tends to move when "spirited driving on B roads"....

have u ever let your gauge go all the way to the bottom n just relied on the computer? am not suggesting to do that, but thats a big no no in a diesel, as opposed to petrol where u just stik summore petrol in if u run out.

hello

i always keep the tank filled on 1/4 as the MIN (not less) to prevent the sensor breaking when in the bottom position.

cheers/Igor

[hertsnminds]

The range indicator can change depending upon engine load. If you are rolling down hill in fifth your mpg is 99.9 if you are going up hill in third your mpg could be down to less than 20. Which would mean if you had one gallon in the tank the range indicator could be showing anything between 99.9 and 20 miles.

Even when the range indicator goes to -- (less than zero) you still have a few miles left it's just that the calculations start to become meaningless.

[JoBaxi]

Thanks for the replies,

Just i had like 1.5gallons or thereabouts by looking at fuel gauge, but range indicter suggested another 112miles to go. i did reset it, and was parked at lights when i did that, and it came back to me as 112...

yeah, i probably wont let it go under a quater myself, but i'l fill up next week, and compare results against computer and fuel gague to see which gives the better accuracy...

I'l let you know what i find. oh my drving style returns average about 39-42mpg.

[Dunkelmann]

yeah, i probably wont let it go under a quater myself,

Jo - what's the problem with letting a diesel run low in the tank?

[JoBaxi]

Not good for the Cat i heard......

[igormus]

Not good for the Cat i heard......

hello

i do not see any link between fuel level and cat :o

cheers

[caveman_si]

There isnt any link between the fuel tank and the cat except the fuel.

The main issues i know of with running diesels low on fuel is the crap in the bottom of the tank. Diesel are more prone to this then petrols due to bacterical growth that can occur in diesel. and a low tank means its more likely to get sucked up and block filters.

The other main issue and ive no idea if this applies to avensis, (my experince is with psa hdi engines) is a low fuel tank can cause the fuel pump in the tank to over heat, and an over heated fuel pump self destructs and shreds itself and needs replacing. Not cheap. The fuel in the fuel tank acts a coolant/heat sink.

[igormus]

There isnt any link between the fuel tank and the cat except the fuel.

The main issues i know of with running diesels low on fuel is the crap in the bottom of the tank. Diesel are more prone to this then petrols due to bacterical growth that can occur in diesel. and a low tank means its more likely to get sucked up and block filters.

The other main issue and ive no idea if this applies to avensis, (my experince is with psa hdi engines) is a low fuel tank can cause the fuel pump in the tank to over heat, and an over heated fuel pump self destructs and shreds itself and needs replacing. Not cheap. The fuel in the fuel tank acts a coolant/heat sink.

hello

as to bacterias you mentioned -- they can only be originated in case of a long time of storing the car in the garage without drive + during this time the parafine is normally dropped . but in case the car is running consuming diesel -- it is circulated and not any bacterias are originated at all.

cheers

[JoBaxi]

Yeah, well thats what i heard. Iv never really made a habit of keeping low fuel, mainly due to the crap at the bottom of the tank stuff,

So low fuel not good for diesel pump (expensive part ryt?)

right. where wud we be without the internet, i learnt something new today.

[Dunkelmann]

right. where wud we be without the internet, i learnt something new today.

Indeed - a great way to publish urban myths.

It all sounds a bit dubious to me. As Igormus points out there is enough fluid motion in the tank to continually keep particles suspended and to distribute bacteria. You may get sludge if you leave the car undriven for a long time. There is a fuel filter for larger particles which should get cleaned out regularly at certain service intervals I imagine. As long as the fuel pump has a continual supply of fuel, it doesn't "know" whether your tank is full or nearly empty. There will be a slight pressure difference between the two - but hell - it's a pump and supposed to cope.

[john_robot]

Well, how about this:

2005 D-4D T3-X, full tank, driving for 120 miles = fuel gauge shows FULL, Trip computer says: 6.5 L / 100 km, all looking perfect

reached London, slowed down, first traffic lights (1minute or so on idle) = fuel gauge hand starts to move ( meaning I can see it ) for 1/2 divider, Trip computer starts counting: 6.5, 6.6, 6.7 ...... up to 12.5

Turned off the display for health and safety reasons, turned it back on when I got home (after 12 miles urban ). Result: gauge shows 2/3 full, computer - 7.2 L / 100km, range 480km left.

tra-la-la

Once the hand shows half tank, it starts moving down 3 times faster than when on the upper half.

When 1/3 is left ECU insists I only have 70km left.

on full tank the computer now shows 720km /used to show 640/.

ideas?

[igormus]

Well, how about this:

2005 D-4D T3-X, full tank, driving for 120 miles = fuel gauge shows FULL, Trip computer says: 6.5 L / 100 km, all looking perfect

reached London, slowed down, first traffic lights (1minute or so on idle) = fuel gauge hand starts to move ( meaning I can see it ) for 1/2 divider, Trip computer starts counting: 6.5, 6.6, 6.7 ...... up to 12.5

Turned off the display for health and safety reasons, turned it back on when I got home (after 12 miles urban ). Result: gauge shows 2/3 full, computer - 7.2 L / 100km, range 480km left.

tra-la-la

Once the hand shows half tank, it starts moving down 3 times faster than when on the upper half.

When 1/3 is left ECU insists I only have 70km left.

on full tank the computer now shows 720km /used to show 640/.

ideas?

Hello mate

I deem that a PC error or misadjustment between primer level gauge and ECU is available.

But -- firstly please advise total milage drived since 2005 ---whether you have already changed the unit (pump+filter+level gauge) since 2005, depending on milage. Cheers/Igor

[Fitter]

Hi there,

bought used avensis D4D today, and on the way home. fuel light comes on. thats no problems, and i was in my home town by now. But the thing that worried me, by looking at the fuel gauge, i would have thought maybe 1.5 gallons of fuel left in there. maybe a tad more, but the range indictarer was saying 112miles...

now, i dont really plan to let the fuel gauge ever come that low that the light will come on. (diesel cars, i like to keep a bit of fuel in the tank). but which one to i believe if i ever have to rely on one or the other?

Thanks.

The fuel gauge shows the total fuel remaining in the tank. The range indicator shows the remaining distance to the reserve fuel. The range is calculated based on remaining fuel and past consumption as it is impossible to know future consumption.

The range will vary with driving habits and road and traffic conditions and is updated every mile or Km. Waiting at traffic lights or jams will affect the actual range. It is good practice, as previously stated to fiil up when quarter full.

Fitter

[rockspotter]

I wouldn't recommend it, but I recently had no choice to keep driving looking for fuel and my range told me I had 2 miles left when I found some. All with no problem at all. Avensis 2.0 D4D.

[t-spiritpete]

Hi there,

bought used avensis D4D today, and on the way home. fuel light comes on. thats no problems, and i was in my home town by now. But the thing that worried me, by looking at the fuel gauge, i would have thought maybe 1.5 gallons of fuel left in there. maybe a tad more, but the range indictarer was saying 112miles...

now, i dont really plan to let the fuel gauge ever come that low that the light will come on. (diesel cars, i like to keep a bit of fuel in the tank). but which one to i believe if i ever have to rely on one or the other?

Thanks.

The fuel gauge shows the total fuel remaining in the tank. The range indicator shows the remaining distance to the reserve fuel. The range is calculated based on remaining fuel and past consumption as it is impossible to know future consumption.

The range will vary with driving habits and road and traffic conditions and is updated every mile or Km. Waiting at traffic lights or jams will affect the actual range. It is good practice, as previously stated to fiil up when quarter full.

Fitter

Correct!

Pete.

[Aamir2892]

I did once. Computer said 0miles and fuel gauge was so low it looked like it was in the off position when the ignition is off. Also to ask does the fuel gauge on your cars make a noise when they move up and down. I'm mean if you have half a tank you turn the key to ON the fuel gauge rises and makes a buzz sound while it moves???