[supremeBaleno]

@srikanthns, if you are straining the engine by upshifting early, you can "hear/feel" it. Just go with the feedback you get from the engine and you should be OK, because each car is different. For eg. in Chennai I normally shift to 5th gear @ 40kmph in my Baleno. But with our Swift at Kerala, to shift to 5th, I need to be atleast @ 50kmph.

[srikanthns]

Thank you. But with my kind of driving, I get too few chances to reach 50KMPH in Trivandrum

[VeluM]

Maruti recommends shifting into 5th gear at speeds equal to and for above 50kmph. I don't think shifting into 5th at 40kmph is a good idea - engine rpm will be too low, might cause knocking. Definitely not if you have the AC on.

[supremeBaleno]

I would think that this would vary from car to car (even between Maruti cars). And more than the manual, the driver is a better judge, based on engine response.

[sumeethaldankar]

Originally Posted by tj123

What I meant by “emptying” means that you should go the lowest possible safe fuel level 3-5 lits (in most cases) before refueling.

Actually the idea is to have minimum amount of stale fuel in your fuel tank to reduce gum build up in fuel tank, lines & carburetor/ fuel injection components.

Keep in mind that stale fuel rapidly catalyzes and aids rapid decomposition of the newly added fuel. Hence try to deliberately "empty" your tank at least once in a quarter.

Hello,
Some of you guys have mentioned that the fuel tank should be used up till last 4-5 litres every quarter.I have started filling up when the car reaches the half tank mark for the last few months.I do not understand how the fuel which was filled 1st will be not be used then the fuel filled up later.

Eg i fill up a full tank 1st (~ 30 litres,m800) and use up the 1st 15 litres of fuel.Now there is 15 litres at the bottom of the tank.Now if i fill the tank again with another 15 litres of fuel again, which will fill up above the existing bottom 15 litres, what prevents the car from using the bottom 15 litres 1st.Is is that the outlet of a fuel tank to the fuel pump in cars is located at the top of the tank and not at the bottom?I hope you guys understand my point.

[Gansan]

Originally Posted by sumeethaldankar

Hi guys,
i am still waiting for someone to clarify my above point.

thanks

How long does it take to reach the half tank mark? If you are adding half a tank of fresh fuel at least once month, you are fine - for MPFI models. Even later will be ok if your car is a carb version.

[sumeethaldankar]

Originally Posted by Gansan

How long does it take to reach the half tank mark? If you are adding half a tank of fresh fuel at least once month, you are fine - for MPFI models. Even later will be ok if your car is a carb version.

Hi,
half tank's done in 20 days time, though i am not sure why the no of days will matter.My car is carb model.

[Gansan]

Originally Posted by sumeethaldankar

Hi,
half tank's done in 20 days time, though i am not sure why the no of days will matter.My car is carb model.

Petrol staying in the tank unused for long periods will lose octane rating and cause deposits which may clog fuel injectors or carb jets, though injectors are more vulnerable.

[sumeethaldankar]

Originally Posted by Gansan

Petrol staying in the tank unused for long periods will lose octane rating and cause deposits which may clog fuel injectors or carb jets, though injectors are more vulnerable.

Well that probably explains why i had carb problems before and had to get the same o/h.Secondary butterfly jammed ,lots of deposits when the carb was opened.I would wonder why it would give problems even when the car was used sparingly.

[ikoneer]

The major content of this thread is for MT driving only.

I have an i10 AT. Can you also please let me know the best driving techniques for AT cars. How can i achieve maximum FE driving an AT with 100% a/c and city driving.

[Garipagol]

A few common sense tricks. Filling up at half empty will help petrol mileage. As you drive the petrol sloshes around in the tank and evaporates. To prevent the build-up of excessive pressure in the tank there is a safety valve in the cap which reduces the pressure by releasing the vapor. Typically in between a filling cycle you may lose close to .5 ltr. Filling up when half empty helps in lowering the evaporation since there is less empty space in the tank for evaporation to take place. Also, it helps to monitor consumption when you stick to filling a half tank.

Secondly newer cars have a electric fuel pump in the tank. This pump is kept cool by the fuel. If you expose the pump by going too low on fuel it may run hot. Not good.

Thirdly given the dirty fuel we use, the bottom of the tank will be have some of gooy dirt. If you suck that into your fuel system the injectors will clog. The car will suddenly lose acceleration and you can collect someone in the rear.

When approaching a stop (traffic signal/policeman, cows obstacles) which is obvious use the gears to slow down rather than pumping the gas and braking at the last moment. You will save fuel. But be careful of rejected F1 drivers who may suddenly cut into your path and stand on their brakes. This was my Honda serviceman's advice and I have followed it since with good results.

iKoneer, with AT buildup speed slowly. Essentially relax and enjoy the drive.

BTW, at night when stopping at a light etc. keep your brake pressed to keep your brake lights on till you have another car stopped behind you. Another piece of advice from the same guys as above.

[GTO]

Originally Posted by ikoneer

The major content of this thread is for MT driving only.

I have an i10 AT. Can you also please let me know the best driving techniques for AT cars. How can i achieve maximum FE driving an AT with 100% a/c and city driving.

I have just the thread for you : Discussion on i10 AT FE

Two more recommended reads:

AT versus MT

AT : Lower mileage. Why?

[jinojohnt]

1self: the hyundai manual states that if the waiting period as more that 3 minutes, the fuel consumed is equal to 1 kilometer worth of travel!! something to think about isn't it?

This sounds reasonable, here's my logic:
In my Cielo, if I put 3rd gear on a level road, the car moves at 20 km/hr smoothly and continuously, without pressing the accelerator (at engine idle speed). Going at this speed, it would cover 1 km in 3 minutes. That means I am wasting 1 kilometer worth of petrol if I idle for 3 minutes.

[jinojohnt]

The maximum mileage I've ever achieved on my Cielo when I was regularly using it for my Office commute is 14.87 km/litre of 'speed' petrol. (Single person in the car, without a/c, empty to full tank petrol filling, one third city and the rest highway driving. The drive used to be 15 km non-stop to office and 15 km non-stop back to home. The maximum stops at 4 or 5 junctions used to be 5 seconds, but traffic was not very light - you'll have only 10 meter gap between vehicles all the time.)

This is how I achieved this (these practises may be difficult, but possible):

1.Use the optimum rpm at all gears.
Check your user manual to find the most efficient rpm. Suppose it is about 1100 rpm.Now find out the car's speed at different gears in the same rpm.
Let's assume the following speeds at 1100 rpm:
2nd gear - 15 km/hr
3rd gear - 25 km/hr
4th gear - 35 km/hr
5th gear - 50 km/hr
If you are forced to go in a particular gear because of traffic, go in the optimum speed for that particular gear. Donot unnecessarily raise the rpm and tail the car in front hoping that some time you'll be able to overtake. Raise the rpm only When you are clear for over-taking, and shift to the higher gear as soon as possible.
Try to maintain the optimum rpm on 5th gear as far as possible.

2. Close all windows to reduce drag.
This may be difficult without a/c, but I felt ok with just the fan blower on.
May be because I used to drive to office at 8:00 A.M and drive back home at 8:00 P.M, when it was cold.

3. Drive in such a way that you may not need to slam the brakes often - this is really possible if you are soft on the accelerator.

4. Suitable Gear range for acceleration is different from Gear Range for decceleration.
The speed range that is mentioned in the user manual for different gears is for acceleration.
When you slow down by taking your foot off the accelerator, you'll be able to remain in that gear at a much lower speed.
For example, if the user manual recommends a speed range of 40 km/hr to 50 km/hr for 4th gear, you will be able to use 4th gear while slowing down even till 30 km/hr. (Do not down-shift the gear at the moment when the speed falls below 40 km/hr.) You need to down-shift the gear only just before you press the accelerator to move forward.
Please note this may not be suitable for drivers who race all the time, because they would need better engine braking.

I am not sure how much effect does each of the above points have on mileage, your views/comments are welcome.

[srikanthns]

Originally Posted by jinojohnt

T
May be because I used to drive to office at 8:00 A.M and drive back home at 8:00 P.M, when it was cold.

.

My commute to Office in TVM too is around 16.5KM and the starting time is also around 800AM so no hassles in the morning. But in the evening I start at 1700 or 1730hrs and I get caught in the maddening traffic. Being a newbie driver also does not help. It is a real bumper to bumper traffic for the last 3 Km. But in spite of all this I am getting around 14KMPL in my 1999 April carb ZEN. So I am not complaining