[gshanky]

Originally Posted by swiftnfurious

Be it any company, not only TATA, the FE marathon stuff is CRAP ! Why would you "fool" customers showing unreal FE. On another note, its the obsession of the people to the FE that inspires these manufactures to go for these stupid gimmicks. It would be great if they do better things like Mahindra Great Escape / Fortuner 4WD Boot camps or something on those lines which will show the actual strengths of a car - may be intra city / state runs etc!

I agree with the spirit. In the same vein every advertisement is a way to fool customers - either it be emotional appeal or convenient data based facts, the idea is to lure customers. I am not sure why mileage marathon is bad.

If X no. of customers claim they get 25 kmpl, then more people will obviously follow - at least thats the idea. In fact I would say TATA needs more such advertisements.

[AVR]

Originally Posted by aniketi

Poor Tata. Whatever they do, people will get behind them. All knows that all companies do these type of marketing gimmicks, then why be so harsh on Tata only?

Very true aniketi. Was about to post the same before I saw you had already said it! I increasingly find opinions about Tata being rather dismissive for whatever they do. They are honestly trying to do the right things (improved fit-n-finish in Aria/Manza, arguably more reliable vehicles with every evolution and focusing on mileage as in case of this thread's subject. Eventually, only results will matter but we have to give it to Tata for showing the "intent" to improve/enhance/explore customer choices.

Coming back to the thread, the mileage numbers are pretty impressive and its good that people actually get such numbers with a normal four-wheeler. I somehow can never relate to such numbers thanks to the kind of vehicles I own/owned (Safari/Jeep/Bullet)

[honeybee]

Slightly off topic, but I think the majority opinion says if the car is driven within the 60-80kmph band (in the highest possible gear) you should achieve the best FE figures. My guess is this has to do with the engine RPMs.

If that's true, and if it's also true that you cannot "drive like a moped" on highways, where your average speeds are going to be in excess of 80kmph, why are the manufacturers not providing overdrives and maybe six or seven gears, so that even at three-digit speeds the engine RPMs are respectably lower?

[nukeblitz]

I think it has to do a lot to do with engine rpms, gear and throttle. If i'm not mistaken, atleast on gasoline engines, the ecu feeds fuel in depending on the position of the throttle. This is to ensure complete combustion as the air/fuel mixture has to have perfect proportions. So, depending on the hear ratios, cruising along in 5th gear at 80kmph with 20% throttle will give more fe than cruising along in 4th hear at 60kmph with 20% as the fuel consumption with time should be approximately equal but the car's covering a higher distance in 5th in the same time.

Further, ecus have a but off mode when you step of the throttle. No fuel is injected and the wheels turn the engine. Carbs don't. That's why is better to coast in gear with a new car. This is something hypermilers use - called blip and coast, i think.

I tried to use some of these principles when driving and my fe went up from 11.5 to 14.5 in vista tdi

[nomadabhi]

That is correctly said. Indian Road conditions are far from being Ideal.

With my regular drive Old Gen Estilo returns me 11kmpl-13kmpl whereas If I am able to control my loose foot, It has returned me 18kmpl wherein officially its 12.6kmpl

Why dont you guess check the fuel efficiency on Vashi-Mahape-Kalyan route... (consider your vehicle to be pathfinder on lunar surface)

[Suess]

Originally Posted by swiftnfurious

Highly unlikely that this was done inside City. City traffic will definitely not allow anyone to drive at a constant speed of 60 kmph or so in top gear to ensure such a high mileage, even on a Sunday. So ideally this is taken at straight roads with very minimal traffic and as you said which enables smooth acceleration & deceleration which are must for attaining such heavy FE figures.

And what you said it right. Improving roads will definitely improve mileage for those who drive with in the right way & minimize the maintenance on a car. And reduce accidents too in my opinion.

I think you don't have to be in highest gear at 60kmph to achieve best mileage. upto 3rd gear(depending on the cars, it could be a different gear), you can drive at minimum speed for that gear without using accelarator(in so called crawling speed). in that case your car is running at lowest possible RPM for that gear(mostly less than 800-900rpm) and in 3rd gear you will get about 17-18kmph(varies car to car). so, that is most fuel effeceint way of driving the car. when you go in higher gear try to keep rpm as low as possible with the help of accelerator. speed is not of any significance in getting better mileage.

ya, better infrastructure can do wonders to economy and all. for that, i think we have to wait for long, giving the conditions of our governance.

[Latheesh]

It is possible to achieve higher mileage if you drive carefully

I got ~ 25 KMPL (10 % with AC ) during my last drive to hometown. 350 KM drive; mixture of very good road to very bad roads.

Otherwise my mileage figure stands 12-15 in the city and 17-19 highway.

[trakesht]

Originally Posted by Suess

you can drive at minimum speed for that gear without using accelarator(in so called crawling speed). in that case your car is running at lowest possible RPM for that gear(mostly less than 800-900rpm) and in 3rd gear you will get about 17-18kmph(varies car to car). so, that is most fuel effeceint way of driving the car. when you go in higher gear try to keep rpm as low as possible with the help of accelerator. speed is not of any significance in getting better mileage.

Unfortunately, this is incorrect. Fuel efficiency of most IC engines wrt RPM is like an inverted parabola- low at low rpms, rising with increasing rpm till a particular rpm, then dropping down with increasing rpm. The highest FE will be available in a band- roughly around halfway between idle and red-line.
I am fairly sure that FE vs throttle position has a similar profile- ie low at idle and fully open and the highest at somewhere in between. Have to check my old text books, but I believe has to do with the engine running on lean/rich ratios than ideal combustion.