[Jeroen]

Originally Posted by asingh1977

Could you elaborate a bit more on starting the car with the clutch pressed in, and being in N. How is this easier on the battery and starter armature. My wife always starts the vehicle in this method, I do not. Is it different for petrol vs. diesel induced..?

No difference between petrol and diesel. Actually the biggest advantage is safety rather then anything else. If your routine is to always press the clutch upon starting you can never accidentally start whilst in gear.

Jeroen

[studentonwheels]

Hello BHPians
I've been hearing a lot from either side of the argument, but should you idle your car before driving in winter? When I say winter, I mean subfreezing temperatures. Would love to get a technical answer here, because it seems to me that modern cars do not need to be warmed up due to fuel injection technology, but I've noticed a significant difference in the way my car drives on a cold morning with temperatures well below freezing when I don't warm it up beforehand, and I can't get around the fact that putting extra load on a cold engine by driving it immediately will add to wear and tear in the long run.
Your opinions?

[ashis89]

Originally Posted by studentonwheels

Hello BHPians
....but I've noticed a significant difference in the way my car drives on a cold morning with temperatures well below freezing when I don't warm it up beforehand, and I can't get around the fact that putting extra load on a cold engine by driving it immediately will add to wear and tear in the long run.
Your opinions?

You are right. When we start an engine after a long gap (more than an hour or so) in any weather, it lacks lubrication in different parts of the engine. Oil takes a couple of minutes to circulate throughout the engine. Ideally, 30-60 secs is enough for the circulation. Next comes the engine reaching optimum temperature. Since the engine is designed to operate efficiently at the optimum operating temperature, it's performance will be slightly lower when it is cold. Depending on the ambient temperature depending on the season (in India, we don't have freezing temperatures in most cities), you could drive the car/bike very sedately for a few kms till it reaches the optimum temperature before you start pushing it.

[Jeroen]

Originally Posted by studentonwheels

Hello BHPians
and I can't get around the fact that putting extra load on a cold engine by driving it immediately will add to wear and tear in the long run.
Your opinions?

I have tried to explain this already earlier on in this thread. The problem is that a cold engine at idle hardly warms up at all. The most relevant wear your (cold) engine will incur is wear of the cilinder liners / piston rings as the lub oil will not provide good adhesion and therefor lubrication. So the solution is to start and more or less drive off straight away but very sedately.

Feel free to consult your owners manual and you are very likely to see something along similar lines.

Originally Posted by ashis89

. Oil takes a couple of minutes to circulate throughout the engine. Ideally, 30-60 secs is enough for the circulation. .

No it doesn’t. Believe me, if a car engine would run with no oil circulation for a minute you would definitely see some damage to bearings and such.

Once a engine is shut down there is still oil left everywhere, noticeably between bearing. That will take care of the initial lubrication at start. Within seconds of your engine having started, oil will have circulated all over the engine.

The problem is not so much the circulation, but the temperature of the oil and as I explained earlier the fact that the engine parts themselves, are cold. Which means the lubrication is suboptimal for various reasons, too high viscosity, not adhering to parts etc.

Only when it gets exceptionally cold, say well below -25-30oC, , you might see some problems with oil circulation. But you would change to very different lub oils in those circumstance. Although I have driven classic Alfa Spider successfully to the North Pole in the winter at -27oC with no problems whatsoever. (top down obviously!)

All of the above is also true for other lubricants in your car, i.e. transmission oil in your gearbox/differential. They don’t warm up at all with the engine idling away. So again, just drive off sedately.

Good luck and remember, don’t idle. Bad for your engine and bad for the environment as well!


Jeroen

[studentonwheels]

Originally Posted by Jeroen

Only when it gets exceptionally cold, say well below -25-30oC, , you might see some problems with oil circulation. But you would change to very different lub oils in those circumstance. Although I have driven classic Alfa Spider successfully to the North Pole in the winter at -27oC with no problems whatsoever. (top down obviously!)

All of the above is also true for other lubricants in your car, i.e. transmission oil in your gearbox/differential. They don’t warm up at all with the engine idling away. So again, just drive off sedately.

Good luck and remember, don’t idle. Bad for your engine and bad for the environment as well!


Jeroen

Thanks for the info. Actually it does get really cold in Iowa (-35C last week). And you mentioned an interesting point about the type of oil. Ideally, should someone living in a place with cold winters change to an oil with a higher W rating? And should I do oil changes before winter to a higher W rated oil?

[Jeroen]

Originally Posted by studentonwheels

Thanks for the info. Actually it does get really cold in Iowa (-35C last week). And you mentioned an interesting point about the type of oil. Ideally, should someone living in a place with cold winters change to an oil with a higher W rating? And should I do oil changes before winter to a higher W rated oil?

I think you need to stick religiously to what the manufacturer recommends. So check your owner manual, it will have a section on oil.

The internet has an awful lot of opinions when it comes to lub oil. Very few have the means to actually make any claims as to what to do or not to do. E.g. With this oil my engine revs better, with this oil it runs smoother etc.

There are perfectly good reasons why those statements are being made. But rarely have they to do with facts, more about perception and or wish full thinking. Certainly very few have done any measurements to substantiate such claims. But again that is just my opinion on Internet wisdom on lub oil advise.

So stick with the car manufacturers recommendations. I have a few cars for which different oils are recommended for extreme winter conditions.


Jeroen

[sudeep11787]

Hi All,

I tried to find an answer to my query everywhere, but couldn't.
I just got a ciaz vdi SHVS. Now everytime i come to a halt, engine immediately stops, doesnt even take a second. Looking at all these posts, i am sure it's not following the idle before shutting down recommendation. Do you think it's safe to assume that maruti must have made necessary arrangements to keep turbo good in the SHVS models with an auto stop start function? Also, for engine life, is lugging worse than driving at around 2-2.5K rpm, when turbo is working well?

Thanks!

[ptaneja]

Originally Posted by sudeep11787

Hi All,

I tried to find an answer to my query everywhere, but couldn't.
I just got a ciaz vdi SHVS. Now everytime i come to a halt, engine immediately stops, doesnt even take a second. Looking at all these posts, i am sure it's not following the idle before shutting down recommendation. Do you think it's safe to assume that maruti must have made necessary arrangements to keep turbo good in the SHVS models with an auto stop start function? Also, for engine life, is lugging worse than driving at around 2-2.5K rpm, when turbo is working well?

Thanks!

I am in the same boat as you are.
To make matters simple, I do not worry too much about idle'ing. All I follow is a simple rule - keep RPM below 2K for the last half a km or so. I do not idle the car before killing it, people standing next to it dont like the diesel odor. As far as engine life, or battery life is concerned, I am assuming Maruti must have done some testing/QA - and only time will tell. For now, its about 18 months with Ciaz - all good so far.

[IN-RJ]

Originally Posted by sudeep11787

Hi All,

I tried to find an answer to my query everywhere, but couldn't..when turbo is working well?

Originally Posted by ptaneja

I am in the same boat as you are.

This question is also bothering me since Mahindra has launched ‘Micro-hybrid’ technology and now it is maruti.

It is clearly mentioned in owner’s manual (SHVS model) to idle the engine before final turn off.


My humble question to owners/ experts.. can we turn off the ‘ENGINE A-OFF’ system while running (I am asking only for the situation of complete halt; otherwise Engine power assistant system will not work in case of CIAZ)?

If this can be done, then we can prevent the harm to turbo after a high speed run and not need to get drive slow/ keeping the rpm low for some time before coming to halt.

‘ENGINE A-OFF’ or ‘Micro-hybrid’ systems are to save fuel in B to B type traffic situations. It is of no use when vehicle is on a highway/ open road run.
if it is not possible to turn it off, can the trick marked with green line can be used?

[shashanka]

Originally Posted by Jeroen

No difference between petrol and diesel. Actually the biggest advantage is safety rather then anything else. If your routine is to always press the clutch upon starting you can never accidentally start whilst in gear.
Jeroen

Succinctly & neatly put - in fact there are a few mfrs (& their models - the Hyundai Getz, eg) who incorporate the system as a built-in precaution (for duffers like me). The car wont start unless the clutch is depressed - regardless of whether it is in gear or in neutral.

Originally Posted by sgiitk

One think which is bothering me. Some of the 'soft hybrids' whatever they mean, switch off the engine after a few seconds. They restart it when you press the throttle. What happens to the gentle cooling off period?

I assume you are referring to normal urban / b-to-b traffic conditions, where one is unlikely to race the engine to lunatic rpms. Under such conditions (frequent stop /start) the t/c bearings on cars (which are journal/bush type bearings & not low friction ball/roller types as fitted to some larger engines) will retain sufficient oil film on the surfaces to prevent boundary lubrication conditions on restart. And boundary lubrication (where the oil film has broken down or drained-off & metal-to-metal contact is established) is the condition which mfrs are at pains to avoid. Thus the 1 minute rule before moving off & before stopping, specially under hooligan, boy-racer conditions.

[KkVaidya]

Originally Posted by shashanka

Succinctly & neatly put - in fact there are a few mfrs (& their models - the Hyundai Getz, eg) who incorporate the system as a built-in precaution (for duffers like me). The car wont start unless the clutch is depressed - regardless of whether it is in gear or in neutral.

Another more important reason for depressing the clutch while starting is to relieve the load on the engine while starting. This is essential for bigger engines.

[Jeroen]

Originally Posted by KkVaidya

Another more important reason for depressing the clutch while starting is to relieve the load on the engine while starting. This is essential for bigger engines.

Not really, all that turns is a shaft in some oil. So as long as it is not very very very cold this really doesn't matter. Try for yourself: with the engine on and gear in neutral. Depress the clutch, does your engine speed up, do you hear the engine sounding different with the clutch in or out?

So yes in theory, but in practice it doesn't really matter much unless very very cold.
Jeroen

[KkVaidya]

Originally Posted by Jeroen

Not really, all that turns is a shaft in some oil. So as long as it is not very very very cold this really doesn't matter. Try for yourself: with the engine on and gear in neutral. Depress the clutch, does your engine speed up, do you hear the engine sounding different with the clutch in or out?
Jeroen

Yes I do hear the idle sound change in my 2.5ltr CRDe Thar when the clutch is depressed, the engine sounds like it is more free even though rpm change would be very slight that cannot be noticed on tachometer guage.

[feluda86]

Originally Posted by GTO

Switch the engine off only if your turbo has had sufficient time to cool down. And don't revv the minute you start her up again! I personally wouldn't switch a turbo-engine off at traffic lights.

I have meticulously been following the idling rule for my 2 years old i-Dtec. However, I have a confusion. Honda states excessive idling as "harsh/severe" driving condition and recommends more frequent engine oil change. My question in this regard is the following: Is there an optimum idling time (especially in traffic signals)? Does idling in signals for more than 1-2 minutes cause any damage to engine/turbo or does it just reduce the lifespan of the engine oil?

Thanks!

[sgiitk]

One thing which foxes me. Many cars (Diesels are almost invariably Turbocharged) come with start-stop technology. Now the engines shut down at the drop of a hat. So how does the slow shut down strategy work in those.