[dadu]

Then someone will want to see a Mumbai data or a delhi data, Believe it or Not OR test it yourself.

Global data is available, India specific, i am not aware. Although the report link in the first post is a result of an Indian study only.

Even if your Exide was required to be changed at 24 months due to frequent starts and you saved 10% on fuel at 10k running a year, you would have saved much more in the fuel savings than the battery replacement cost.

Originally Posted by hrag

I will not comment on the FE saving until I see some Indian data.

So what does the temperature gauge show? When I idle at a traffic light, my temp. gauge needle should drop? Drastically? Because it is idling and not operating at peak temperature?

Gentlemen, all I'm saying is - If you have tried it yourself and then show data, things become easier to believe.

Edit: with not switching off at every signal, my OEM Exide battery was replaced at ~39 months / 60,000 km. The battery died because a regulator failure was not looked into in time. The replacement Amaron (with the same idling habit) has been with me for ~26 months / 30,000 km. My starter motor has never given me trouble. I don't know how green the grass is on the other side.

[bblost]

I usually switch off at two signals.
Cyber Towers and Banajara HIlls Rd12.
They both have wait times in excess of 100 seconds.

When the car is OFF, its completly OFF. No Ice, AC or lights.

[hrag]

Fair enough, I don't believe it.

[hillram]

I had a strange experiance once when i turned off my Engine in Corsa..the central locking opened and and young lad tried opening my rear door and run away with my laptop bag(with my laptop in it)..I was saved,but too a decision never to switch off engine at red lights.

[bblost]

Originally Posted by hillram

I had a strange experiance once when i turned off my Engine in Corsa..the central locking opened and and young lad tried opening my rear door and run away with my laptop bag(with my laptop in it)..I was saved,but too a decision never to switch off engine at red lights.

Pass the laptop strap thru a locked seat belt to keep it secure.

btw where was this?

[ph03n!x]

I have noticed my puny Kinetic Honda's 100cc engine save 3 KM per Litre of fuel after I started switching off - my last mileage was 35.5+ KMPL, and I used to get under 33 KMPL when I used to not switch off.

I refuel at the same pump, drive in the same roads and nothing else, not even a service has been done to alter the driving conditions.

Though I *can* give a real-life experience that goes like "my ODO at the last filling reads xyz. I have filled 6.56 L of petrol, and I have run 240 KM in the ODO... - this is with switch-off at signals. The values for not switching off...", I do not want to do it because I have been there and done that.

I replaced my battery last in 2006 March, and top it with distilled water about 4 or 5 times a year. The scooter goes for service hardly twice a year. The starter motor has never been touched in 12+ years since I bought this scooter.

I know that Cars and Scooters are apples and oranges, but both are fruits (engines), and drink the same water (Petrol!) - i dare not do such a experiment in any car of mine (or yours!!) because the impact will only be higher!

[HappyWheels]

I switch off engine if the waiting time is more than or close to 60 sec. Anything less, I dont!

During night times, I also switch off the headlight, when in the signal. This is not for saving the bulb(!), but to avoid the glaring effect it might have on others due to vehicle parked in front.

[teknophobia]

Let's see, manufacturer recommended Idle times for my TCIC... 1 min so that makes it 2 mins of minimum idle for start/stop, consequently for a 15 second stop I would have to wait 2 mins, maybe get lynched by the drivers of the vehicles stuck behind me, or run over by an impatient driver of a 30 ton trailer truck, I am reasonably sure that my life is worth more than 3,100 a month, not to mention that diesels tend to be amazingly efficient at idle, so the savings would be closer to 31 bucks a month.

[dadu]

The manufacturers recommend this for cold starts generically as they cannot define or enforce you to drive slow after cold start and cannot judge your good/bad driving habits. There are technicalities behind this. Why do they recommend this....read on

Originally Posted by teknophobia

Let's see, manufacturer recommended Idle times for my TCIC... 1 min so that makes it 2 mins of minimum idle for start/stop, consequently for a 15 second stop I would have to wait 2 mins, maybe get lynched by the drivers of the vehicles stuck behind me, or run over by an impatient driver of a 30 ton trailer truck, I am reasonably sure that my life is worth more than 3,100 a month, not to mention that diesels tend to be amazingly efficient at idle, so the savings would be closer to 31 bucks a month.

[amitk26]

Dadu,

I read the other thread so in simple words does it mean that if a turbo charged diesel operating under optimal conditions and running below the limits when turbo kicks off is switched off for a couple of minutes it does not need idling before switching off as Turbo was getting lubricated when the engine was running ?
So how this is different then case of idling before parking ?

Secondly what about restarting the engine with out idling after couple of mins, for practical scenarious what is the time gap in start - stop cycle which needs idling to lubricate turbo pump.

Regards
Amit

Originally Posted by dadu

The manufacturers recommend this for cold starts generically as they cannot define or enforce you to drive slow after cold start and cannot judge your good/bad driving habits. There are technicalities behind this. Why do they recommend this....read on

[IndigoXLGrandDi]

The Turbocharged Engines Need to Idle for minimum 30 seconds After Starting and Before Stopping the Engine.

Tata Motors Limited has Recommended that the Engine should be idled for 30 seconds Irrespective of the
1. Engine Temperature and
2. Time Interval between the Stopping the Engine and Again Starting the Engine.
This means even if shut off the Engine for 5-10 minutes, you should idle for 30 seconds after starting the Engine.

So Switching off the Engine at traffic signals makes no sense.

[mayuresh]

I usually tend to switch off car engine if a stop at a signal is going to last at least 30 seconds. Fortunately most signals have timers or you otherwise can judge the duration at signals that you regularly pass by.

What is a good thumb rule for this, considering technical factors and FE?

Also does the optimum duration depend on engine and fuel type?

This may be purely psychological, but with the noise the engine shows when starting and stopping for petrol and diesel is quite different. I do somehow tend to avoid stopping and restarting a diesel engine at signals while tend to quickly switch off petrol engine at signals.

[tbppjpr]

I used to switch off my M800 petrol car's engine at signal if it was showing more than 30-40 seconds wait. But now after buying a turbo diesel car I never shut off engine. Its becasue of lot of readings about turbo diesel engine that it takes long time to warm-up, turbo unit needs some oil circulation before shutting off etc. etc.

[shibujp]

I own a Swift diesel. I usually switch off the engine if the wait is more than 10 secs - easier when the signal has a countdown - at those that don't I switch off the engine if the light turns red as I pull up.

I need to start up a few seconds before the light changes as the diesel doesn't start up as fast as a petrol and it is usually practice to start it after the service light goes off.

Drive on,
Shibu

[suhaas307]

This was discussed at the Ford safety-drive workshop that I'd attended last year.

If the traffic-signal has a timer and you'd have to wait for over a minute, it's advised that you switch off the engine. Avoid idling for over a minute. It's not good for the FE figures in the long run.

Also remember that when you start a car, it consumes more fuel than usual. So switch it off only when the traffic-signal requires you to wait for 60 seconds or more.

Oh and there is one thing I'd like to say.

If you approach a signal that requires you to wait for over a minute and you turn the engine off, I request everyone to have the presence of mind to lock all the doors at all times! If it has the auto-lock/unlock function, remember to lock the doors again, once it unlocks.

I will stress on this, because there have been numerous instances where hoodlums take this opportunity to get into your car. They will attempt to get in, either to steal something valuable that's in sight, or just to mug you.

If I recall correctly, something like this happened on a rainy day, at the traffic-signal right in front of Oasis Mall on the Intermediate Ring Road, Bangalore. Imagine the scene!

Think about it. You've had a hard day at work and you need to cool off. You're stressed, and a traffic signal is a blessing in disguise as it gives you the opportunity to turn up the volume and sit back for a minute or so. Generally, one tends to be a little less attentive while waiting at a traffic signal. And these hooligans know this. This is when the 'blessing in disguise' turns into a horror story waiting to happen.

So I strongly advise all viewers to keep a look out and be generally as attentive as possible, even when you aren't actually driving. Because this is when people take it easy and relax, and it's the perfect time for an imbecile to take advantage of the situation.

Drive safe!