[kavensri]

I always had this question in my mind. I searched the internet to find the answer and I am somehow not convinced with the answers provided there.
So, I thought of asking the same here.
From what I understand, detecting the 'remaining fuel quantity' data could be much more complex. But is it that complex to implement with the latest technology/sensors?

[KarthikK]

Range left in kilometres is a direct derivative of fuel left in the tank, and most modern vehicles have the distance to empty or range number built into the console options nowadays.

Litres left in the tank is not a direct indicator of how important the number is to the driver/rider, range is a more usable number in my opinion. 5 litres left in a 250cc bike tank can mean 150km range, same 5 litres left in a petrol luxury sedan will mean 20km left .

P.S - some vehicles have an option of showing fuel consumed in litres for a tripmeter distance. So the data is there from the sensors, it is probably just about manufacturers showing usable and easily understandable parts of that data

[ashis89]

Originally Posted by kavensri

I always had this question in my mind. I searched the internet to find the answer and I am somehow not convinced with the answers provided there.
So, I thought of asking the same here.
From what I understand, detecting the 'remaining fuel quantity' data could be much more complex. But is it that complex to implement with the latest technology/sensors?

The location of the float and the comparing it with total volume of the fuel tank should give the fuel remaining. But when the vehicle is tilted or moving on uneven ground, the float won’t receive the correct measure.

(Fuel input - Fuel output/consumed) seems the most accurate method but I am not confident how advanced/accurate a sensor can be to measure fuel input. Input would depend on fuel nozzle size and the speed of delivery. Need to account for evaporation and leakage. Doable but is it worth the effort?

I find DTE meters to be inaccurate.

[Rehaan]

Related thread : link (Distance to Empty (DTE): How exactly is it calculated?)

[Sedate driver]

In my Hector, the fuel available is displayed as a percentage in the MG App. This is fairly accurate also. The DTE or the range varies as per the road, traffic and driving conditions but the displayed percentage of fuel left in tank seems to be correct with an acceptable tolerance of +/- 1L.

[kavensri]

Originally Posted by Sedate driver

In my Hector, the fuel available is displayed as a percentage in the MG App. This is fairly accurate also. The DTE or the range varies as per the road, traffic and driving conditions but the displayed percentage of fuel left in tank seems to be correct with an acceptable tolerance of +/- 1L.

This is what exactly I was looking for. I was not aware that Hector displays such information in their app.
I know others may have different opinion, but for me, I would be more comfortable if I get to know the 'remaining fuel quantity' data rather than DTE data.

[Turbanator]

Originally Posted by kavensri

This is what exactly I was looking for.
I know others may have different opinion, but for me, I would be more comfortable if I get to know the 'remaining fuel quantity' data rather than DTE data.

I will agree, based on the car Say I am driving my sports car the way it is supposed to, and the range shows 90Km, and I know the next fuel pump that has XP-100 is at least 130Km away, so if I know I still have 20 Ltrs left, instead of DTE, I can drive the car more sedately without worrying too much. Of course, currently, the DTE changes in real-time on most premium cars, but the value of actual fuel can be more comforting.

So why are the gauges not available to show this is probably because most people will be keen to know how far they can reach and not necessarily do the calculation of fuel left x average mileage they are getting, and knowing the actual mileage in the last few km will be pretty tricky.

On a regular car where the average mileage does not deviate that much, one is better off with DTE, hope this helps.

[MT_Hyderabad]

The reason is simple..

If you know you have 3 litre remaining, you will try to delay the refill. However, your fuel pump will die when there is 3 litre remaining in the tank.

[Rodie09]

I think inaccuracy in fuel remaining can be challenged by someone legally as misinformation. While inaccuracy in range is kind of acceptable and difficult to challenge in court of law.

So, it's a safer option for manufacturer.

[Jeroen]

Originally Posted by MT_Hyderabad

The reason is simple..

If you know you have 3 litre remaining, you will try to delay the refill. However, your fuel pump will die when there is 3 litre remaining in the tank.

It should not! You should be able to get almost the last drop out of the tank. The suction inlet pipe in the tank is usually set in a little recess in the fuel tank. So you can literally suck the tank just about dry.

You should not let your tank be pumped dry. For several reasons. Most of the reasons mentioned on the internet are simply not relevant or even true. The idea that you will get a lot of debris with the last bit of fuel is bogus. Debris by its very nature will settle in the lowest point of your tank. No matter what., which means directly below the inlet suction pipe. If you have debris in the fuel its going to get sucked up, irrespective of the level of your tank.

That is why many in-situ tank fuel pump have strainer!

The other non reason often mentioned is the fuel pump heating up when the fuel runs low. This is simply not relevant and not happening.

The real reason you don't want to run your tank empty is two potential issues, all to do with fuel injection. The high pressure fuel pumps will quickly get damaged when run dry. The other reason, mostly on diesels, if you run the tank dry you might have to bleed the fuel system. Older systems often came with a little manual prime pump.

Jeroen

[ex-innova-guy]

Toyota is generally known to be reliable, but my Innova once left me stranded due to the DTE figure shown. I have a habit of refuelling whenever it drops below 90 km. One day I didn't follow that and was going to refuel around the 50 km mark. Car died on me when it had 60 km of DTE left. Just a minute before, I could feel the throttle response lagging, and the next minute, the car died on me. I had to call my dad, who was 10 minutes away, and soon called the SA. He advised checking the fuel pump condition, and he diagnosed that I had essentially run out of fuel! After getting an earful from dad, I went on to the nearest fuel bunk and refuel it. After refuel, had to keep pumping the fuel motor to start the car. A good lesson to never rely too much on the sensors!

[MT_Hyderabad]

Originally Posted by Jeroen

It should not! You should be able to get almost the last drop out of the tank. The suction inlet pipe in the tank is usually set in a little recess in the fuel tank. So you can literally suck the tank just about dry.

I have read in the thread on Tata Safari Issues that rpm needle started fluctuating when the car was run low on fuel and it went away after fuel pump replacement. This is where my knowledge on fuel pump failure is coming from. I haven't experienced it myself.

I think that a car sees many inclines and declines and running low on fuel may keep the fuel pump occasionally less submerged or even allow air to get sucked in, which will cause the damage. It could be a wrong understanding.

A small 12 litre fuel tank motorcycle manufacturer recommends that you should keep at least three liters in the tank. A 60 L tank car recommends that you should keep 10 L always in the tank. Both the references are attached. The tank listed capacities may be slightly different, I didn't search for them.

This is where my recommendation of not listing actual fuel volume is coming from. If one knows that there is 3L remaining, he will try to delay the refill. In commonly used motorcycles, 3 L means 10 days of 10 km/day ride.
In cars, going to three liters will cause some damage somewhere, which forces companies like Mahindra to recommend 10 L. They don't know that many cars in India haven't seen the tank getting filled by more than 10 L throughout there life.

Ironically, I have not received any vehicle with more than 10% fuel in the tank. You are usually compelled to drive directly to the nearest fuel pump after taking your vehicle's delivery.

[ObsessedByFIAT]

In contrast to showing the amount of fuel remaining, it's much easier to show the amount of fuel consumed. A simple math will tell how much fuel is remaining.
Renault Kwid and Triber both have this feature. They display fairly accurate amount of fuel consumed in litres. Haven't explored if Kiger too has this feature.

Link to thread with pics of Triber's console. Image credits to the original source.

https://www.team-bhp.com/forum/techn...ml#post5641154 (FE Measurement - Clinical method and Practical Method)

[Redex]

Simple, distance to empty. Refill when you have at least 100km range left, unless you know your next filling station is further than 100km.
Other data i.e. litres left, fuel consumption rate ec etc are all pointless. All you need to know is how far can I go.
Why take the risk of running out keep the tank at least 1/4 full. You never know if your next fuel station is open or has run out of fuel. In that case you still need enough fuel to reach the second fuel station. Can't do that if you only have 3 litres left !!!

You never know if you might need to make an emergency trip to take a family member to hospital. Oh dear got to stop and fill up with fuel because I only have 3 litres left.

In my car a 1/4 tank full is good for nearly 150kms. I just won't take the risk.

[Tony2298]

Don’t know about any mass market cars which show actual volume of fuel left, I guess most of them show Distance to Empty(DTE) or Range which would be more helpful to the driver in planning his course of journey and fuel stops to be taken.

However I’ve observed Volvo Buses do show actual volume of fuel left as well as Distance to Empty, I do wish our cars also had a similar system just for the sake of information for those of us who like to crunch numbers