How Erratic Is Your Fuel Gauge?

[Vyker]

I decided to take some pictures of my fuel gauge to show you how strange it is, and how it seems to have its own mind.

so here we have the needle and just over half tank at 283miles.

Now at this point, other drivers and I would be thinking "fantastic, im heading toward 550miles/tank"

then all of sudden... BAM!

under 100 miles later, the light comes on, with the needle at 1/4 tank.

now half tank would be 35ltrs, light comes on at 10ltrs...

so thats ~100miles in 25ltrs :o

to add to this, my needle sometimes is spot on, and other times is soo far off, i have to guess by my trip counter when i will need to fill up!

are your needles this strange?

[Mark W]

Its all in the name - its only a "gauge" and not there to measure the exact quantity of fuel remaining.

Dont think I have ever had a car where its accurate. Every car Ive had - you get a fair few miles out of it before the guage even drops from full (Had a 2.0 vectra years ago and could get 100 miles out of it before the gauge started to move.....300 miles at 1/2 way......then BAM! - Filling up again at 400 miles because the lights on)

[Moffet]

Your car must be a lot more frugal than mine... I only get about 300 miles until the red light comes on V-Power!

Is the tank not narrower at the bottom and therefore the guage will go down faster? Sometimes when I fill it up it takes 10 minutes after I leave the garage for the guage to go up...

[Unregistered_User]

Chuff me, that comes on early!

Mine only illuminates when it heads right near the final line!

J

[Rikos]

Thats what i was thinking Jamie, mine doesnt come on until just above the bottom line.

But i do notice that i get much more mileage out of the first half of the tank than the second half.

[Moffet]

Mine only illuminates when it heads right near the final line!

Same here.

What sort of mileage do you get from a tank Jamie?

[Rikos]

I know i'm not jamie but i normally get between 400 and 440.

[Moffet]

Was asking Jamie as a fellow S/C runner... sorry I seem to be taking this Vyker!

[Rikos]

Sorry i'm not in the special group

[elexes]

i know once mine goes to half full for some reason it just starts to vaporise

[Vyker]

Your car must be a lot more frugal than mine...

Sometimes when I fill it up it takes 10 minutes after I leave the garage for the guage to go up...

I suffer from that as well, Moffet, sometimes, it takes over a day before the needle starts to rise to its place, most of the time, ive already driven 100 miles or so, so it only goes up to 3/4.

mine is not that frugal, i get on average 320miles per 60ltrs [tank with light on], shows in my signature my current MPG.

i know once mine goes to half full for some reason it just starts to vaporise

could this be a result of, as Moffet says, a narrower tank near the bottom?

if i remember rightly, the tank has two coils inside, i dont think it is measure with a float, can anyone confirm?

[Mark W]

This has shocked me.....I'm getting ~25mpg out my GS430 is I drive it reasonable, 23 if I give it the boot....

Are these typical IS mpg figures, due to mods or you all drive around with your foot flat to the floor?

Previously had an LS until it had to go to the great car graveyard and actually considered an IS to help save on the fuel bills - In the end I opted for a GS anyway - but I would have been a little disappointed if I'd have bought an IS for that reason and only got 26mpg.

(not that I consider an IS to be a disappointment to drive - I just prefer larger cars)

[johnbaby]

I decided to take some pictures of my fuel gauge to show you how strange it is, and how it seems to have its own mind.

so here we have the needle and just over half tank at 283miles.

Now at this point, other drivers and I would be thinking "fantastic, im heading toward 550miles/tank"

then all of sudden... BAM!

under 100 miles later, the light comes on, with the needle at 1/4 tank.

now half tank would be 35ltrs, light comes on at 10ltrs...

so thats ~100miles in 25ltrs :o

to add to this, my needle sometimes is spot on, and other times is soo far off, i have to guess by my trip counter when i will need to fill up!

are your needles this strange?

[johnbaby]

how old is ur is? does the fuel gauge get less accurate with time?? and using v power should i get 400 miles out of a tank 360 is most i can manage

[WylieCoyote]

Mine's always consistent I must admit. They're only an estimate anyway. I remember when I had my Renault 5, the amount of petrol entirely depended on what sort of corner I was going round. If it was just a slight bend, I may make it to the Petrol station whereas if it was a more severe curve, I may make it to Aberdeen. The only true test of how full your tank is, is when it's running, it has petrol in it, when it coughs and splutters to a stop, it doesn't. Makes sense no?

Keith :)

[Vyker]

how old is ur is? does the fuel gauge get less accurate with time?? and using v power should i get 400 miles out of a tank 360 is most i can manage

Mines on a T plate, one of the first ones so ive been told.

i dont know if they get less accurate with time, i cant see why they should :S

i dont know if v power is any different tbh, 360 is _decent_.

If im honest, i cant really moan about MPG [i dont think i do either], but if i drive with a less heavy right foot, im sure i can get the thing to churn out 450miles easily!

I enjoy the drive too much, i always i want to rev the crap out of it, and follow with a quick shift, good fun, great car to drive :D

and for that reason, i dont care what MPG i get - although id like an accurate reading ;)

[eXOBeX]

Mine goes down even when I'm running on LPG, then every so often seems to realise that I've used hardly any petrol and jumps back up again, by about a quarter!

[Unregistered_User]

Mine only illuminates when it heads right near the final line!

Same here.

What sort of mileage do you get from a tank Jamie?

I'm lucky to get around 300 - but the usual factors obviously take a stance - driving manner, weather etc etc.

But yeah, around 300ish.

J

[WylieCoyote]

Mine only illuminates when it heads right near the final line!

Same here.

What sort of mileage do you get from a tank Jamie?

I'm lucky to get around 300 - but the usual factors obviously take a stance - driving manner, weather etc etc.

But yeah, around 300ish.

J

Snap

[Unregistered_User]

And your N/A as well :o

The best MPG I've had out of the car so far was 27 I think!!!

J

[Monster-Mat]

ok.....

there was a fix for sticking fuel guages on the early cars, it was a fault in the instrument cluster, it even happened on my 2001.

however the fuel tank has 2 sender units, one with the pump, and one on the other side of the tank, it is usually the separate sender which gives the faulty reading, as the tank is a saddle tank the 2 readings are compared to give a total level.

i suggest, removing the seat base, and cleaning the contacts where the plugs go into the 2 units.

they will be found under x2 silver plates

[Vyker]

Right... love the reply.. Mat!

now, by seat base you mean the back seats?

going to search through the lexus manual cd ive got, to try and find tank diagrams... sunny outside, might get the toolbox out.

cheers for that Mat!

[Mike_B]

This has shocked me.....I'm getting ~25mpg out my GS430 is I drive it reasonable, 23 if I give it the boot....

Are these typical IS mpg figures, due to mods or you all drive around with your foot flat to the floor?

Previously had an LS until it had to go to the great car graveyard and actually considered an IS to help save on the fuel bills - In the end I opted for a GS anyway - but I would have been a little disappointed if I'd have bought an IS for that reason and only got 26mpg.

(not that I consider an IS to be a disappointment to drive - I just prefer larger cars)

I used to get about 32mpg average out of my IS200SE auto - and 25 doing the same sort of driving in my GS430SE. It's only 7 mpg - but it sounds better if you say that the IS has 28% better consumption! Wouldn't go back though, maybe I'd consider an IS300 but the GS is just in a different league to be honest. Bugger the petrol cost!

[colbecoz]

I'm averaging 29 MPG at present. Have noticed the guage does act funny every now and again, but, I don't pay much attention to fuel guage unless the light comes on. I calculate MPG from fill up and trip mileage. Anyway, didn't buy my IS200 sport for good MPG return, I bought it for comfort, fun, looks and reliability. I love my Lexy....

Col..................

[smudge]

Mine only illuminates when it heads right near the final line!

Same here.

What sort of mileage do you get from a tank Jamie?

I'm lucky to get around 300 - but the usual factors obviously take a stance - driving manner, weather etc etc.

But yeah, around 300ish.

J