[Latheesh]

It is very difficult to achieve the same on AVI-CBE route. Awaiting details!

Best I could manage in my Spark was around 24-25 KMPL during one of my relaxed driving from BLR to KNR ( ~ 340 KM). Mix of highway+bad road + 2 lane ghat road+ city road.

[GTO]

Such news has ZERO relevance to the real world and real car owners. So, a Manza gave 46 kpl under "ideal test conditions" and a Fiesta did "3x kpl". So what? These driving conditions are impossible to replicate in the real world. And even if you do, it will be outright dangerous!! Such stunts serve little other purpose than feeding the ever-hungry PR machinery.

Plus, these figures are useless unless there is some degree of relativity (as in the ARAI figures).

Originally Posted by Klub Class

We've managed to achieve a mileage of 47.4 km/l using our Fiat GP. But, no prizes for guessing the fact that we're going downhill in the ghat section and letting the car roll on, without providing any throttle or clutch inputs!!

Klub Klass, that was really dangerous. Please don't repeat; your life is more valuable than some more kpl. Remember, using engine braking is mandatory on downhill drives. Don't let the car just roll on without touching the clutch!

Originally Posted by sam_sant2005

Two reasons for me to believe it is fake :-
1) My friends have Manza Qjt and it gives 13-14 in city and gives a max 16-18 in highway mileage.

And that is exactly what most Manza owners should expect in the real world.

[Klub Class]

Please excuse me for this post!

Originally Posted by GTO

Klub Klass, that was really dangerous. Please don't repeat; your life is more valuable than some more kpl. Remember, using engine braking is mandatory on downhill drives. Don't let the car just roll on without touching the clutch!

Well. Now, I realized that it's my bad that I didn't provide the reason why we chose to do that.

The more faster we negotiate the ghat section, quicker my younger brother,aged 6, throw up. Thus, my dad let the car roll on, in the lower gears, say 2nd & 3rd gears(ie, we're not letting the car roll on, in neutral gear). The use of engine braking ensured that we braked and changed the gears only when the situation demanded. We're not focusing on achieving phenomenal mileage while negotiating the ghat section. In fact, we had reset the MID dada while filling fuel to brim before we went downhill and we noticed the mileage figure only when we stopped the car for my brother to throw up!

But, I do agree with you, especially on the 'life is more important than kmpl' part.

PS: Stangely, I used the word 'clutch' instead of 'brake' in my last post. Again, the blame goes to the stupid me.

[vikram_d]

I really wonder where you got your facts from. Even when your foot is off the accelerator the car will stills consume some amount of fuel. If there was no fuel going in, then the engine would stall. The same applies to you point about the ECU cutting off fuel. When coasting downhill with you foot off the accelerator the ECU will not cut off the fuel supply it will only reduce the amount of fuel that is being burnt by the engine by altering the fuel injection cycle. No fuel = stalled engine. Period.

Originally Posted by lucifer1881

If it is downhill for most of the journey, then all he had to do was slot it in gear and take his foot off the clutch. As long as his foot was off the accelerator, the car will not use any fuel. Instead of the engine turning the wheels, the wheels run the engine. This is what gives you engine braking. In non-ECU cars, the engine uses idling worth of fuel. In modern cars, the ECU shuts off fuel supply when it detects engine braking. If it is not downhill, then I am very curious to know how such a feat was achieved.

[PAVAN KADAM]

This report is all over the Media.

What is the actual Truth content in all this.......Anyone?

Tata Manza Clocks An Incredible Mileage Of 46.33 Km Per Litre To Join Limca Book Of Records - Yahoo! Lifestyle India

Limca Book of Records sees Tata Manza Quadrajet Aura ABS go 46.33 kmpl | Rush Lane

Tata Manza clocks mileage of 46 km a litre, enters Limca Book of Records - www.daily.bhaskar.com

Tata Manza Records Incredible Mileage Of 46.33 KMPL | Autoplugged.com

[cruiser@0523]

I doubt the practicality of such claims, indeed they are possible but not in real life, remember a few years back some mag had done a test by running a logan for straight 24 hours ? it had returned an FE of 35kmpl, also the similar test was done back in the day with a daewoo matiz, which did 35 something kmpl.

[Geo_Ipe]

Well, if you notice, the wordings in all the media reports are nearly the same. Nowhere does it mention how the figure was measured eactly. Looks more like a press release than a piece of news. Looks a little hoax-ish to me! But its sure to catch the common man's eye. Guess TATA's pulled this one off with ease.

[DRIV3R]

1) The pic shown is not taken between Coimbatore-Avinashi
2) Coimbatore-Avinashi route has some 10 ~ 15 'Take Diversions' (due to road widening), where the car should have been in 2nd or 3rd gear max.
3) The report is not factual, no details about how the FE was measured, what speeds were maintained, usage of AC etc.

So, please take this with bucket-loads of salt, and don't spread the word, being a BHPian. Useless PR stunt, this.

[Johnny_]

Originally Posted by lucifer1881

If it is downhill for most of the journey, then all he had to do was slot it in gear and take his foot off the clutch. As long as his foot was off the accelerator, the car will not use any fuel. Instead of the engine turning the wheels, the wheels run the engine. This is what gives you engine braking. In non-ECU cars, the engine uses idling worth of fuel. In modern cars, the ECU shuts off fuel supply when it detects engine braking. If it is not downhill, then I am very curious to know how such a feat was achieved.

You are spot on about the engine braking thing, it's called regenerative braking and is usually found in Hybrid cars. It couldn't work in Manza because it's not a hybrid.

Originally Posted by rajeev k

Boss, wheels driving the engine is not engine braking.
Engine braking is where the retarding forces within an engine are used to slow a vehicle down, as opposed to using an external braking mechanism.

Agree with you, it was wrongly put. Engine braking and Regenerative Braking are two different things. Though Engine braking is capitalized in the form of Regenerative Braking in Hybrid cars, but in non-hybrids, these are two different things.

Originally Posted by Klub Class

Mr. Narayana R Menon really deserve a standing ovation! If he reveal his driving pratices, I would be super duper happy!

Slightly OT : We've managed to achieve a mileage of 47.4 km/l using our Fiat GP. But, no prizes for guessing the fact that we're going downhill in the ghat section and letting the car roll on, without providing any throttle or clutch inputs!!



Ain't this feat achieved in the presence of Limca Book of Records authorities? If yes, then I wonder how you call this a false claim by the TATA motors!

That would have required you to switch off your engine. Would the power steering function when the engine is switched off? I have seen the hydraulic ones don't function when the engine is switched off. Besides its risky too.

Originally Posted by GSM

Have they launched any new PS Games such as "Need for Kilometres" or something? Practically impossible, as far as I could see. But I also remember a case on Bajaj Boxer Mileage Champion at Chennai. A Father and Son Duo (both are Bullet Mechanics), clocking, hold your breath, 191 Kmpl and 187 kmpl respectively.

Looking at all these numbers, and my own mileage of approx 8 or 8.5 kmpl, I feel inferior. Any company?

191 and 187 kmpl from a Bajaj Boxer?
Sounds insanely high for a 100 cc bike. Nevertheless, I too should look for Bullet Mechanics and coax them to do a similar trick on my bike too.
Thanks for sharing the info with us.

[typeOnegative]

Originally Posted by lucifer1881

... As long as his foot was off the accelerator, the car will not use any fuel. ...

Whattttt???

You mean to say that the engine does not consume fuel even while idling?

[lucifer1881]

Okay let me try to explain.

Originally Posted by Johnny_

You are spot on about the engine braking thing, it's called regenerative braking and is usually found in Hybrid cars. It couldn't work in Manza because it's not a hybrid.

Originally Posted by Johnny_

Agree with you, it was wrongly put. Engine braking and Regenerative Braking are two different things. Though Engine braking is capitalized in the form of Regenerative Braking in Hybrid cars, but in non-hybrids, these are two different things.

I am not talking of regenerative braking. I do not understand how hybrid cars work. I am talking of engine braking. What gives you engine braking?

You are driving downhill in, say, second gear. Your foot is off the clutch, which means the driveshaft is coupled with the powertrain. The accelerator pedal is _not_ pressed. The engine revs build up despite your foot off the gas. Why does that happen? It happens because your driveshaft which is being rotated by your drive wheels exerts a force on the powertrain. The powertrain resists that force. This resistance is what gives you engine braking.

Suppose instead of second, you were in third gear. The speed will build up to the recommended speed in third gear. All other things are constant - no riding clutch, foot off the accelerator. This speed is also driven by the driveshaft and not the engine.

In both cases above, the driveshaft is driving the powertrain. The powertrain is not driving the driveshaft. In modern cars with ECUs, once the ECU detects that the powertrain is not doing any useful work (i.e. driving the wheels), it realises that engine braking is in progress. The ECU shuts off fuel supply. The pistons in the engine move not because of combustion. They move because the driveshaft moves the transmission which is attached to the engine flywheel which is attached to the crankshaft which are attached to the pistons.

In other words, the wheels move the piston.

In non-ECU cars, the engine will continue using 'idling' worth of fuel since the fuel supply is not cut off. In this case too, the drive wheels moving the powertrain create the resistance which give you engine braking.

Originally Posted by typeOnegative

Whattttt???

You mean to say that the engine does not consume fuel even while idling?

Please refer above.

Please read this from wikipedia: "Additionally, most modern engines don't use any fuel while engine braking which helps reduce fuel consumption."
URL: http://en.wikipedia.org/wiki/Engine_braking

[typeOnegative]

@lucifer: That is interesting. However, what keeps the other systems of the car going i.e. hydraulic and electrical / electronic system. I can understand lower than idling quantity of fuel being used while coasting downhill, but not the 'no fuel' part.

[lucifer1881]

Originally Posted by typeOnegative

@lucifer: That is interesting. However, what keeps the other systems of the car going i.e. hydraulic and electrical / electronic system. I can understand lower than idling quantity of fuel being used while coasting downhill, but not the 'no fuel' part.

The engine is still running. It does not matter whether it is combustion running it or the drive wheels. As long as the engine runs, the fan belt runs, the alternator runs, the hydraulic system runs, the brake vacuum is maintained, etc.

[ACM]

I believe the report is genuine and also purely a PR excercise. In the real world one cannot expect these kind of numbers, neither with the Manza, or the Fiesta or the Octavia for that matter. (All three of these are really fuel effecient vehicles).

On a slightl OT

During the last few outstation trips with that I have made with the Laura and the Aria, have figured out ways of getting more than 20kmpl just for the heck of it. But you sure are going to get tired with the effort and revert to normal (read safer) driving.

Wipers, Headlights, Fog lights, music system, AC blower level and temperature levels do contribute a lot to the fuel effeciency or the absence of it. Just head lights and fogs together can cause you to lose between 1-2 kmpl depending on the type of lights. Wipers too drain fuel (but would you drive without using wipers in the Rain?)

Of course filling in higher levels of air pressure in the tyres can save fuel big time, but it is really unsafe. Here the saving is only interms of the load in the hydraulic power steering.

What I am getting at is that the values being touted for records are possible, but real life values will necessarily be less than even the ARAI values.

It is one thing to do this for PR and to make records but definately not something we guys need get hyper about especially while comparing vehicles, if another car manufacturer got down to it, they may be able to closely replicate the values in similar conditions with a similar expertise level driver.

[Johnny_]

Originally Posted by lucifer1881

Okay let me try to explain.



I am not talking of regenerative braking. I do not understand how hybrid cars work. I am talking of engine braking. What gives you engine braking?

You are driving downhill in, say, second gear. Your foot is off the clutch, which means the driveshaft is coupled with the powertrain. The accelerator pedal is _not_ pressed. The engine revs build up despite your foot off the gas. Why does that happen? It happens because your driveshaft which is being rotated by your drive wheels exerts a force on the powertrain. The powertrain resists that force. This resistance is what gives you engine braking.

Suppose instead of second, you were in third gear. The speed will build up to the recommended speed in third gear. All other things are constant - no riding clutch, foot off the accelerator. This speed is also driven by the driveshaft and not the engine.

In both cases above, the driveshaft is driving the powertrain. The powertrain is not driving the driveshaft. In modern cars with ECUs, once the ECU detects that the powertrain is not doing any useful work (i.e. driving the wheels), it realises that engine braking is in progress. The ECU shuts off fuel supply. The pistons in the engine move not because of combustion. They move because the driveshaft moves the transmission which is attached to the engine flywheel which is attached to the crankshaft which are attached to the pistons.

In other words, the wheels move the piston.

In non-ECU cars, the engine will continue using 'idling' worth of fuel since the fuel supply is not cut off. In this case too, the drive wheels moving the powertrain create the resistance which give you engine braking.


Please refer above.

Please read this from wikipedia: "Additionally, most modern engines don't use any fuel while engine braking which helps reduce fuel consumption."
URL: Engine braking - Wikipedia, the free encyclopedia

I got your point Lucifer, and am aware how engine braking works. It helps one save fuel by letting the car stop by itself due to the friction and rolling resistance instead of applying the brakes. Thanks for restating it in detail. It will enlighten the novices.
And in technical terms, it is described as work being done on the system (i.e. mechanical power is given back to engine) instead of work being done by the system (i.e. mechanical power from engine to the wheels).
This is leveraged in the form of Regenerative Braking in Hybrids. Explained it again as you said you weren't aware of it.