Fuel Gauge Accuracy

[tweetyduck]

can anyone tell me how the fuel gauge works and if its possible to make it more accurate? Are there any after market options or more advanced systems that can be fitted.

I reckon that having a accurate gauge is pretty important for my trip so any suggestions would be welcomed.

[gazelle]

Link to how it works found using google.

To know with accuracy the amount in the tank you will need to take into consideration the shape of the tank and the position of the sensor, and if you want even more accuracy the attitude of the vehicle.

[tweetyduck]

i saw that thanks when i googled it myself. This was more of a specific question on the one in the defender.

[FridgeFreezer]

Perhaps the first question is why do you need it to be more accurate?

[reb78]

Just do some experiments with the one you have......

Start with a tank brim full, fill it again after the gauge starts to move, when it gets to a quarter gone, half gone and a quarter remaining. That way you will know how much you have in the tank at those points on your gauge.

[tweetyduck]

cos i'd like to know when my tank is empty......or full... or half full.

At the moment i have a sheet that says when its 1/2 full there is X litres left. Whan its full its X litres and when its 1/4 theres this many litres. Which works fine but i was wondering if theres a better way.

@ Reb already done that. You beat me to it.

[JeffR]

Accuracy and fuel gauges on landrovers simply do not ofetn appear in the same sentance. I know when mine is empty cos the engine stops! Don't really matter what the gauge is implying, like a politician, some times it tells the truth sometimes it don't. Personally I now run mine off the Odometer and carry a small can of petrol!!!

[Retroanaconda]

I've always found mine to be pretty reliable. You learn after a while what each point on the gauge means, my "half-full" mark happens at about 160-170 miles, which is pretty much exactly half a tank.

[tweetyduck]

my 1/2 is 275 miles and 1/4 at 410 miles

if my reserve light comes on i can get 66 litres in the tank back to brimmed. Now i'm not really sure how big my tank is, or should be. I think they are 89 litres? So my reserve is 89 - 66 = 23 litres which seems a lot.

[western]

my 1/2 is 275 miles and 1/4 at 410 miles

if my reserve light comes on i can get 66 litres in the tank back to brimmed. Now i'm not really sure how big my tank is, or should be. I think they are 89 litres? So my reserve is 89 - 66 = 23 litres which seems a lot.

Defenders don't have reserve fuel lights, it's a LOW FUEL warning should come on & stay on with 9litres remaining in the tank.

300tdi standard 110 fuel tank is 80 litres capacity.

[tweetyduck]

The reason i say 89 is thats what Rave said somewhere. I now see its 79.5 after another Google and a look at RAVE again.

So my light comes on with 14 litres to go. At least i now know that for sure. Not that i ever want to get to the couple of litres to go stage. Although that filler pipe must hold a few litres.

Thanks

[FridgeFreezer]

I'm not sure why counting litres is any more helpful - when the little needle points to the bottom bit, you need more fuel. If you're expeditioning or just travelling somewhere you don't know where the next fuel station is, then you should have a jerry can or several in reserve anyway.

[tweetyduck]

if you read the initial post i want it to be more accurate. I'm not counting litres at all. Should i just type the intial question again?

[reb78]

I havent actually found mine that innaccurate though Neill, so i'm, not really sure on the problem. Unless you are bouncing around all over the show, the gauge goes one way........steadily (and often alarmingly quickly) towards empty. If you know how far you can go on what is left then surely that will be adequate? The only real innaccuracy is the fact that the float bounces around inside the tank. Not a lot is going to improve that with the design we have.

[tweetyduck]

Thanks. I was more of a case of some after market gadget that may make it linear and accurate. Mine is not perticulary linear and it was just a thought. As i have indicated i know what distance i get to where on the dial. Having seen some of the distances i need to cover 800-1000km with no fuel inbetween i wanted to make sure i know what i have in the tank. That is to say, 1/2 is actually 1/2 and not some unknown. I know its a lot to ask but hence the reason for some miraculous after market sender, or something.

I get the feeling what i already know is all i can ask for. I'll make more records of the distances as i go and this time i'm going to use the GPS to measure as i think the speedo is 5% off and so the miles will be.

I'm still going to whip out the sender and take a look to see if its OK. I might even drain the tank and give it a clean as if i ever do get down low there might be quite a bit of carp in the bottom after 15 years.

[Retroanaconda]

Gauges are non-linear by design. People don't like seeing their newly bought fuel dropping very quickly so they move slower at first.

Td5 fuel gauges are damped by the speedo head if that is any help? Stops it waving about when driving off rough terrain.

[tweetyduck]

not really too bothered about it waving about. Not that it does much anyhow. I knew the non engineers must have had something to do with the gauge being non linear. Its a pretty square tank in a 110 so it shouldn't be hard to make it perfect by design.

Oh well. Off to make some stickers with the real readings. If i make one that says full when its in the red, do you think that may work.

[FridgeFreezer]

You can buy different styles of sender & gauge, VDO do a capacitive dip tube setup for £eek and I think there's a similar one (ATL?) which plugs into a normal gauge for £yikes, plus I've heard of ultrasonic ones for big truck/boat tanks.

The most accurate thing is the Series 1 gauge - a stick.

I still don't really understand the problem though, you have a gauge which tells you roughly the level in the tank, and you have an odometer which tells you roughly how far you've driven (and a GPS which tells you the same again with different lies), if the speedo is 5% out then it'll be 5% out every time so it doesn't matter as the answer is always the same. You know how far you can get on a tank, in distance and probably driving time, and you should have reserve fuel anyway.

I'm struggling to think of a scenario where the combination of distance travelled and needle on gauge is insufficient - or to put it another way, everyone else seems to manage

[cookie64]

my 1/2 is 275 miles and 1/4 at 410 miles

if my reserve light comes on i can get 66 litres in the tank back to brimmed. Now i'm not really sure how big my tank is, or should be. I think they are 89 litres? So my reserve is 89 - 66 = 23 litres which seems a lot.

410!!!!!!!

do you have a super fuel tank or an amazingly efficient truck.

the most i get is 300 on a good day with poncy road tyres and mines a truckcab so light too

O yeh thats 300 to stoped in the hardshoulder BTW

tom

[tweetyduck]

i know what your saying and you're correct. It was just a "could i,,, and is it possible ? " question.

I like the idea of one of those Tubular tank sensors in each tank though. Thats the idea i was looking for.

I'd obviously like it to be spot on. If thats not possible for sensible money then i can live with it. I'll start testing my mileges on every tank to build up a average picture. I also want to know how far i get once i'm in the red. not looking forward to that test. Will drain the tank first and get rid of the carp in the bottom.

I can already carry 40 litres of spare fuel in a Jerry mount on the roof. I want about another 40 to 80 litres and i think i have enough. This may be in another tank or in Jerries (low down) as i'm not yet sure what to do. Additional tanks are very expensive. I can live with 40 litres on the roof but putting nother 40 or even 80 up there is a bit bonkers so additional is going inside or undeneath. They do 125 litre rear tanks that fit in the standard space but i've not looked into it at all. I know wing tanks and side pods work but again they are very expensive.

[tweetyduck]

410!!!!!!!

do you have a super fuel tank or an amazingly efficient truck.

the most i get is 300 on a good day with poncy road tyres and mines a truckcab so light too

O yeh thats 300 to stoped in the hardshoulder BTW

tom

I get ~28MPG.

80 litres is 17.5 Gallons.

410 miles is about 14.5 Gallons of fuel. Leaving 3 gallons in the tank. So readin a 1/4 is about right.