[sidcruise79]

Originally Posted by kannan666

If you are not all that worried by the accuracy, you can also check it this way - On stable ground, when your fuel guage indicates quarter tank, note down the reading. Then, fill up, say 10 litres of fuel, drive around and note down the reading when your fuel guage reaches the same quarter tank mark on stable ground again. The difference in the readings will give you the consumption for the 10lts you filled. Although this is not a very accurate method, it is indicative and in the long run, if you continue this log for a month or two, it will give you a more accurate figure !

That'll give a very rough figure. I do the half to full tank measurement.

[misquitas]

Originally Posted by gpa

As tsk1979 pointed out and in my own experience, rolling up the windows once you have crossed 70 km/hr and then switching on the a/c will ensure that you derive the best FE from the Alto.

In the city, I usually do not cross 65 km/hr and so both the front windows are down a few inches that allows a steady stream of cool air to rush into the vehicle. When on the highways however, I usually roll up the windows entirely once I cross 65 km/hr and then switch on the a/c.

Thanks, GPA, I'll note your advice and try it out.

[Gansan]

Originally Posted by gpa

As tsk1979 pointed out and in my own experience, rolling up the windows once you have crossed 70 km/hr and then switching on the a/c will ensure that you derive the best FE from the Alto.

In the city, I usually do not cross 65 km/hr and so both the front windows are down a few inches that allows a steady stream of cool air to rush into the vehicle. When on the highways however, I usually roll up the windows entirely once I cross 65 km/hr and then switch on the a/c.

This will not work in a climate like that of Chennai (heat+humidity). I wait till the engine reaches normal operating temp and switch on the A/C. It has to remain on at all speeds. Late evenings are the only time you can switch off A/C and open the windows.

I normally maintain a full tank of fuel to minimize evaporation loss, a practice carried over from bike usage. Recently the Service Adviser at MSM noticed this and remarked about the low reading on the odo. He said we should just keep enough petrol we can use up in a week, and re-fill accordingly. His reason was the petrol may reach the bunk after a few weeks of storage, where again it may remain in the sump for a while. He said if apart from this time lag, it remains in our fuel tank also for a period of time (due to low usage) the fuel may start to degenerate and cause injector problems as the car grows old.

I was surprised - because I refill as soon as the fuel gauge goes down below the half level mark. This usually takes 15 - 20 days for me. I follow the same system for my bike, refill as soon as it hits reserve, which is about once a month. I always thought fuel breakdown can occur if it remains in the tank for a very long time. Would like some insights from our members about this aspect.

[9216]

Hello,

I find from the posts here that there are no good methods for measuring FE for a trip. I would like to present a meter for recording fuel consumption. I have been testing this in my Alto

for some time and I am very happy with its performance. Attached is an image of the same.



It indicates:

1. fuel consumed in litres since last reset

2. Distance covered since last reset.

3. The mileage in Km/L

4. Mileage under the current running condition. Does't mean much unless the speed is steady and road is level.

5. True speed. Not much useful. (http://www.team-bhp.com/forum/technical-stuff/58385-how-accurate- speedometers.html)

6. There are two independent data sets and each can be reset independently. (I named them master and minor for identification)

7. Indicates the current consumption rate of fuel on a relative scale of 0-100( this was meant for testing purposes, but found it instructive and fun).

(some data in the image are displayed as blank because the photo was taken while stationary)

Tests have shown it to be accurate to about 2-2.5%, but may depend on driving style.

I understand that some expensive cars have similar facility, but don't know much about it.

Kindly give comments.

Prasad.

[tj123]

If Petrol is left for a period of time, gums and varnishes may build up and precipitate in the , causing "stale fuel". This will cause gums to build up in the fuel tank, lines, and carburetor or fuel injection components making it harder to start the engine.
Normal Petrol may be stored up to 60 days in an approved container (Air tight).

The stale fuel can be used by blending with twice the volume of new petrol, but the blended fuel should be used immediately, otherwise the old fuel will catalyse rapid decomposition of the new, resulting in even larger quantities of stale fuel.

Hence if your car is sitting idle and not logging miles then it is a good practice is to use up and empty your fuel tank before refilling at least once in a quarter.

[Roy.S]

Originally Posted by 9216

I would like to present a meter for recording fuel consumption. I have been testing this in my Alto.....

Looks interesting. Where is this available? 2.5% error is acceptable. I would want one of these just to get a basic idea of the FE. A real-time FE readout would probably help fine tune my city driving.
Highway driving is usually pedal to metal and 'to hell with FE' in my case, but the car always returns 16 kmpl.
EDIT: The device itself looks a little badly put together esp with the exposed wire. Can the display screen be mounted in the dash. In my swift, I'd prefer to put it below the HU.

[gpa]

Originally Posted by Roy.S

Looks interesting. Where is this available?

Seems like an intriguing device. Am keen to know where I can get this.

Kindly shed some light on the same.

Thanks in advance,
gpa

[9216]

Originally Posted by gpa

Seems like an intriguing device. Am keen to know where I can get this.

Originally Posted by Roy.S

....Where is this available?. I would want one of these just to get a basic idea of the FE. A real-time FE readout would probably help fine tune my city driving.

Highway driving is usually pedal to metal and 'to hell with FE' in my case, but the car always returns 16 kmpl.
EDIT: The device itself looks a little badly put together esp with the exposed wire. Can the display screen be mounted in the dash. In my swift, I'd prefer to put it below the HU.

This is a not a commercial product, but a gadget designed and built by myself. And at present, is only a prototype still under test. I can't say that I have sorted out all hardware and software bugs. It definitely lacks the refinement of a commercial product. And I have not calibrated it 'properly'. I just wanted to know how our friends in this forum feel about this effort.

The mileage as shown in the photo is what i get for city driving (mostly 3rd gear, rarely 4th and almost never 5th). The best I get is a little over 24 for a run of about 25km, no a/c, best road, little traffic, around 70km/h.

prasad

[9216]

Originally Posted by Roy.S

A real-time FE readout would probably help fine tune my city driving.

if you mean current FE indication, it fluctuates with every little change in pedal pressure and road conditions. As programmed now, this is displayed only if the speed is more than 30km/h and foot is not removed from accelerator for atleast 10 sec. As such it may not help you for the above. However it will definitely be useful if you are interested in FE for a trip of atleast a few kilometers.

prasad

[Roy.S]

Originally Posted by Roy.S

The device itself looks a little badly put together esp with the exposed wire.....

Originally Posted by 9216

This is a not a commercial product, but a gadget designed and built by myself.....

My apologies. I thought it was a commercially available product.
I am very interested in knowing how you have worked this out. Could you give us some details?
In case you are looking for Beta testers, I volunteer. If a DIY device works with an error of just 2.5%, it certainly has my .

[Gansan]

That is a very nice gadget. I would like to have one.

[gpa]

Originally Posted by 9216

This is a not a commercial product, but a gadget designed and built by myself.

Prasad,

You have come up with a good device.

I too volunteer in case you need a beta tester. What are the bugs you are facing in terms of the software? Is this something your planning on ironing out soon?

Do keep up updated

Cheers,
gpa

[Gansan]

Originally Posted by tj123

If Petrol is left for a period of time, gums and varnishes may build up and precipitate in the , causing "stale fuel". This will cause gums to build up in the fuel tank, lines, and carburetor or fuel injection components making it harder to start the engine.
Normal Petrol may be stored up to 60 days in an approved container (Air tight).

The stale fuel can be used by blending with twice the volume of new petrol, but the blended fuel should be used immediately, otherwise the old fuel will catalyse rapid decomposition of the new, resulting in even larger quantities of stale fuel.

Hence if your car is sitting idle and not logging miles then it is a good practice is to use up and empty your fuel tank before refilling at least once in a quarter.

How can this be accomplished? There always will be some fuel in the tank.

Will it be a good idea to maintain the tank half full, and top up as soon as it reaches this mark? For me this will be about once a month. Can this cause any issues?

[mobike008]

Originally Posted by Gansan

How can this be accomplished? There always will be some fuel in the tank.

Will it be a good idea to maintain the tank half full, and top up as soon as it reaches this mark? For me this will be about once a month. Can this cause any issues?

I dont think there will be any issues as long as you top up from a reputed fuel station. Also, it is not required to top up at half tank.

Thumb rule is do not let it go below 5 litres or whatever reserve is of your car.

[Raccoon]

Originally Posted by Gansan

How can this be accomplished? There always will be some fuel in the tank.

Will it be a good idea to maintain the tank half full, and top up as soon as it reaches this mark? For me this will be about once a month. Can this cause any issues?

As already mentioned by someone above, its a good idea to let the fuel reach the minimum level once every quarter or so and then tank up. This way, most of the fuel in the tank will be new. Its not a good idea nor practical to use the car until the tank is totally empty - you gotta leave about 4-5 liters for the health of the car and the catcon.

I have always followed this practice. Its v important for cars which see low usage.