Fuel Consumption: fuel meter gauge, fuel tank capacity

rockysham000 SG

Dear All,

I have this doubt and qns in mind for quite sometime and finally decide to post if to share with you experts for advice and opinions.

I'm driving the new mitsubishi lancer 1.6 manual. as in the specs, the fuel tank capacity is 50 litres.

My enquiry is more the fuel meter (Empty Full) which doesn't make sense at all given my fuel tank capacitiy.

Before I start giving out the details, let's put the fuel meter gauge having a fraction of 10/10.

- needle pointing to Full 10/10

- needle pointing to Half 5/10

- needle pointing to 2nd last pointer on the gauge before empty 2/10

- Empty 0/10

C when i topped up full tank, i reset my tripmeter. Then i drive all the way till the fuel meter needle point at 2/10, and my milage is only 390.

So i was thinking, at 2/10 left it run only 390km, meaning the remaining 2/10 can only run abt less than 100 than which means my full tank can only run at 400km + for a manual ????

That was my initial thought, but after i pump again to full tank from 2/10, the receipt shows number of litres pump is around 32.5 litres.

Therefore it seems like tat fuel meter gauge needle though pointing at 2/10, the number of litres still inside my tank should be (50litres - 32.5litres) which is 17.5 litres more to go !!!

but qns is, y does the needle drop too fast, 8/10 gauge it takes up 32.5 litres, at 2/10 left, practically it should still have 17.5 litres !!!

is it like that for all cars?? or is it for all cars, during the last remaining fuel meter, it will run down very slow before it'll reach empty ????

given that milage, it can also show that i travel at 390km on a 32.5 litre, which means if i were to average it out a few times, i can take it:

390 divide by 32.5 which is: 12km/litre for fuel consumption ..

but if run at 50 litres, given that fuel meter reading needle at 2/10, do u think i can drive a lot no doubt given the 17.5 litre of fuel still inside??

or most prob the fuel consumption will be only around 7-8 km/litres after considering it at a max fuel tank capacity 50litres point of view???

i would like to if possible, still keep driving and see for myself if the needle will drop slow given 17.5 litres still inside and c how many more km i can go before it reaches slightly empty for me to top up, but i'm afraid the needle will drop too fast till before i know it, till the remaining 17.5 litres can only make me run less than 30km more and i do not wish to see my car tank get totally empty before i re-filled my petrol as it will damage my car engine in the long run ... i'm really clueless on what to do to .....

Qns and doubts seems long, but i do actually have these so many doubts juz abt only single topic all the while in my mind ... hope some experienced and experts out there could clear my doubts.

Many thanks in advance ........

Warmest Regards,
Sham.

jat_pal SG

Could it be because of the shape of the tank itself. Some of the tanks are bottom-big and having a narrower top. That could be ne of the reason.

alberteinstein SG

bro, i read your title knew what your question is already. Your doubt can best be clarified by ppl who go JB to pump petrol, like me.
The straight answer to your question is that the full mark 10/10 is actually not really full. In another words, when your petrol autopump stops for the first time, normally, you(or pump attendent) will still pump a little more with a few more auto stops. THAT, IS NOT FULL!!!
So what is full? Go to a JB station and you will see sg drivers pushing and shaking their cars, like a couple making love in a car. Dun laugh at such sight, because by doing that, they can actually pump in alot more petrol in. Take me as an example. From 3/4 mark, i pump till the first auto stop and it reads like 11-12lits. So i shake the hell out of my car and continue pumping, with many autostops on the way. The REALLY FULL tank takes about 19-20 lit. I mean it is really full because i can really see the petrol in the tank not sipping down into that dark hole. That means i got another 8lit into my tank. An even when you see the petrol as in my case, it is NOT FULL because there is still top space that liquid petrol cant fill(since it will spill when you continue).
Dun worry too much abt the tank capacity. What is impt is the FC and your cal is correct and 12km/lit is reasonable. Hope i clarify your doubts.

KKK84 SG

When my altis’s need point to empty tank, does it mean it’s really empty?? Cos i heard from some forumites tat for nissan cars, the fuel tank is still 20% full when the needle points to empty.

PLC guy SG

fuel meter gague only can tell approximate fuel value, if you meter point to 2/10 and top up fuel at 390km/32.5liters, so your FC is 390/32.5=12km/L, its the normal FC of 1.6L manual car

AE86tofu SG

even so it might be true I would not want 2 take the risk as being stranded in the mid of the road W/O fuel is kinda embarassing and a waste of time

Ecxentrique SG

I drive the 1.6 lancer manual myself. and i know what u mean..

actually my observations are sort of opposite..

my belief is that the markings are not really accurate.. as in the 5/10 mark does not neccessary mean 50% fuel remaining and 0 mean your tank is totally empty.

I find that the (at least as far as my driving style is concerned) every time top up.. the needle will exceed the full tank mark and only start to dip after i exceed 70km..

the needle moves quite slowly at first.. only after the supposed "half way point" then the drop gets faster.

usually i top up when really the needle is at the zero line. at that zero line i do a top up its about 42l. meaning that still got left about 8l in the tank. usually my fc is about 13km/l. So if the fuel tank is really at 50, with the remaining 8l left at the zero line i can still go about 100km.. but usually i dun want to go to that extent of testing..

AirIntake SG

Check out here: http://auto.howstuffworks.com/fuel-gauge.htm/printable
Fuel indicators is not necessarily linear to the tank.

rockysham000 SG

Hi All,

Thanks for all your input .. very informative indeed...

but as done by one of u (nick: Ecxentrique)... u actually pump when the needle point at empty an it will pump about 42 more litres .. which means 8 more litres is already inside which could have run abt 100km more ...

having said this, initially when needle pointing at 2/10, mine can run 390km, so i were to to run till 0/0 .. roughly how many more km can i achieve roughly on top of the 390... ? any estimation ?? or any of u hav a rough idea on it?? as i really would like to know on it ...

i would like to try it out myself (drive till needed point at empty) then to average out my fuel consumption having the milage divided my litres pump (when topping up to full tank) but i'm afraid i may be caught on road with no insufficient fuel ...

so far i hav always calculated my FC when my tank still has abt 17 litres to go ... which means after using abt 33 litres .. i would then take my milage divided by 33 litres ..actually i would like to use abt 43 - 45 litres .. let about 5 litres remaining in the tank then divide the milage by the 43 - 45 litres used.. but i dunno at which point of the fuel gauge will it means i've used around 43-45 litres ... it is near empty ?? or is it when the needle point to empty ??

coz i'm afraid i might overshot and my tank is left abt only 1 litre left .. which is quite bad for my engine and unsafe during my journey where it'll stop at anytime ..

any last advices on this ???

Hope this piece of info here would also be a benefit to those other's who are also unsure and have been dying to know abt these ...

do share your kind thoughts ...

thank you ...

Cpt.ZR SG

i think right... the needle pointing to the 1/10 right until the PLS REFILL sign come out.. i think still can go for abt... 15 km ah? thats what my dad say ah... because i was having my o'level math and he drove me to school [6km] starting the journey with a PLS REFIL sign... i nearly died when i saw tt... cause i tot i will be late for the paper! hahaah and i'm afraid the car will bail out because no oil..

BTW my dad dirve camry 2.4 the 2003 one..

SEI SG

not really sure if this would help but i’ve driven my cr-v below the empty line dont really know how that works running on fumes?? hahaha

ceecookie SG

how come most of the time when ppl pump petrol untill full the fuel gauge needle go slightly above F? Rolling Eyes

fondue SG

The fuel guage is merely a device for you to GUAGE the amount of fuel in your tank. Its position relative to actual amount of fuel depends on the Calibration ... i.e. how the guage is set-up.

I believe most cars now use electronic sensors to guage the fuel. Suppose your tank capacity is 60 litres.

1. The manufacturer can set the sensor to full scale value when there is 60litres of fuel and set it at zero when there is still 20 litres of fuel in the tank. In this case, you will have approx 40 litres when the guage shows 5/10.

2. Or, they can set it at FSV at 55 litres and zero at 10 litres, and your 5/10 will actuall equates to abt 33 litres.

"Approximate" cos as someone mentioned earlier, the guage may not be linear.

The trigger for the low fuel indicator is usually set some where between 1/10 to 2/10 of the full scale value. The balance fuel in the tank when the guage is a Empty is your so call "Reserve tank".

For my car, when the LFI is triggered, I still have close to 20 litres in the tank [70l tank], so I know I can safely travel another 150km based on 9km/l.

Try going to the pump to pump full tank once your LFI is triggered and that will give you an indication of the amount of fuel in tank for the trigger. From there, you can estimate the distance you can venture when you LFI is triggered based on your ave FC (km/litre).

esdontan SG

Anyone know about the fuel consumption for MPV mazda 5?