[Jeroen]

I've participate in the past in extensive research into how engine oil affect engine life. Some basic conclusions we reached:

1 Expensive/versus cheap oil:
We found very little difference between the very expensive brands of oil and their cheaper B-brands in terms of how they affected engine wear.

2 Main contributors to engine wear:
Cooling water temperature and oil filter

A ten degree lower cooling water temperature had very noticeable (negative) impact on engine wear, notably cylinder liners and piston rings.

Improper filter technique had an even bigger impact.

The above is one of the reasons why relatively short drives are often considered 'bad' for an engine. Also, if your cooling water temperature doesn't reach its normal operating value, get the thermostat replaced asap.

Modern engine oils are extremely good and resilient to various contaminations. It's actually the oil filter that needs replacing more frequent than the oil! What we found is that the oil change frequency was actually (technically speaking) more an oil filter change as the oil always outlasted the filter by a very large margin!

On car forums the world over, there are endless debates about when oil should be changed. Car enthusiasts take it as a given that when you change the oil you change the oil filter as well.

Empirical research shows that the filter needs replacing long before the oil does! Also, the quality and filtration efficiency of various oil filters manufacturers differs greatly. Whereas the differences between the various oil manufacturers is minute (except price).

So my advise is to always get the best oil filter money. Figuring out what's a good oil filter is a whole lot easier actually than figuring out what's good engine oil. Just a visual inspection of the filter and its inner bits can be very telling.

Don't know what sort of filters we have here in India. But just to illustrate my point a little video on a comparison between two filters. There's a zillion of these "oil filters" video on you tube.

http://www.youtube.com/watch?v=Q_KXyyxWgPw

The problem with the engine oil is that unless you actually test it, you simply don't know what the quality is. In places like the US you can get your engine oil tested for around $30-40. About the price of an oil change!

So the old better safe than sorry seems a good advise here as well.

if you search the web on this particular topic you will find two things:
- Other research will find huge differences between different oil brands
- Everybody will agree on the huge differences in filters
- You will find surprising little information on how often you really need to
replace filters (i.e. everybody does it default as part of the oil change)

Here's another thought/experience; more than ten years ago my Audi diesels were running on long life oils and the official recommendation was even then somewhere in the 25-30.000 kilometers. Later models got fitted with automatic service interval detection. And I used to get more than 30.000 kilometers.

Now this service interval detections doesn't actually measure the "quality" of the oil as such. What happens is that the car manufacturer, e.g. Audi or BMW has done a lot of research in finding correlations between what we can measure in a car and the quality of the oil. So they basicly have talbles and algorithm on RPM, number of start cycles, various temperatures, driving behavior etc. etc. and they can through a computer compute the oil quality. So it's an indirect measurement if you like, but one the Car Manufacturers trust will live up to in case of warranty claims.

I've seen some papers on the correlation from BMW and interestingly enough the main criteria to which they link the oil quality is fuel usage. There is also a time component in there. (i.e. more fuel in a shorter time frame has a larger detrimental affect on oil quality).

I don't know if the Audi, BMW, VWs etc that get sold in India have these service interval indicator and if so, are they any different from their European/USA equivalents in terms of the tables/correlations. Will Indian dealers tell you to just use them?

My thought/advise;
I think by and large we change our oil to often/early. Never the less,
stick to the interval as stipulated in the official owner manual.

If it has a service interval indicator and the manual says you should use that, use it.

Jeroen

[honeybee]

Wow, that throws this thread right out of the window!

I haven't heward of automatic service interval detection in India, more like a reminder when next service is due. But then to introduce this feature in India these manufacturers will also need to compile data over several years in the Indian conditions.

[greenhorn]

I used to change my oil every 6 months/ 5k kms for the first 3 years. It would feel good immediately after an oil change, but didnt notice any difference in the long term. During 2010 to 2012, I drove only 6K Kms, and being a cheapskate student, I changed the oil only in 2012. And still didnt notice a difference.
Decided to try 1 year/10K Kms. While I had my oil and diesel filters swapped at 5K kms, my engine had become noticeably rough with a drop in pick up after 8 months and some 6K kms. The engine oil was rather sticky and sooty. My car is over 6 years old now though. Thinking of going back to the 5k/6 month change.

[Jeroen]

Originally Posted by honeybee

Wow, that throws this thread right out of the window!

I haven't heward of automatic service interval detection in India, more like a reminder when next service is due. But then to introduce this feature in India these manufacturers will also need to compile data over several years in the Indian conditions.

Well, it might actually be the same. In most of these cars you will get a notice on how many more miles or kilometers to the next service. It sort of does a countdown from about 500 - 800 kilometers to go. But in cars like BMW, Audi, VW etc it gets triggered based on the mechanism as I described before.

To the driver it will materialize as when the next service is due.

So you might well have it here in India. I just wonder if the underlying logic would be that different for India then for the rest of the world. There's plenty of dusty, potholed roads in Europe and the USA as well. Or Australia for that matter.

The real question is, what is materially different in India to the rest of the world, when it comes to engine oil degradation. It's one of those thing you can hypothesize about, but whithout real statistical significant data you can't reach a conclusion.

I was very surprised with the BMW findings, where they essentially corollate to fuel used.

Jeroen

[FlatOut]

Originally Posted by honeybee

Here again the manufacturer usually specifies at each interval what parts or liquids should be replaced and what parts should inspected and 'changed or repaired if necessary'. Why is this not sufficient? As a consumer I expect the service centre to follow the inspection religiously, but not at half the prescribed intervals.

Manufacturers seem to be moving over to a computer-recommended schedule for oil changes, which makes a lot of sense since a car which lives on the motorway all day at part throttle wears its lubricants much less than one which does lots of short, stop-start journeys with a heavy load in the back.

The idea of manufacturers being more concerned with cost of servicing for the first five years of ownership than longevity of engines has been dealt with above quite well, so I'm not going over it yet again. This thread http://www.e90post.com/forums/showthread.php?t=7252 makes for interesting reading.

[tsk1979]

Originally Posted by Jeroen

I've participate in the past in extensive research into how engine oil affect engine life. Some basic conclusions we reached:

1 Expensive/versus cheap oil:
We found very little difference between the very expensive brands of oil and their cheaper B-brands in terms of how they affected engine wear.

2 Main contributors to engine wear:
Cooling water temperature and oil filter

Jeroen

Thanks Jeroen. That was a very informative post.
I have a couple of questions for you
1. Some engine oils, esp for Diesel engines are advertised as "Long Drain engine oils". Are these any different than normal engine oils? Can you really use them for long drain?
2. When you say cooling water temperature, will it help if for a car that does short distances only its best to use a thinner oil. For example 0W30 instead of 15W40 if your vehicle is going to run only about 5kms max on a run?
3. My manual says 15000kms for oil change. I guess if I change oil filter every 7500, it will benefit engine more. Oil change can be done every 15000kms, right? In India you get limited set of oil filters. Normally, for a particular brand of vehicle, there are just 2 brands. Eg Delphi and Elofic.

[honeybee]

I have actually only seen one brand:Purolator.

[Grr7]

Originally Posted by Jeroen

contaminations. It's actually the oil filter that needs replacing more frequent than the oil! What we found is that the oil change frequency was actually (technically speaking) more an oil filter change as the oil always outlasted the filter by a very large margin!

So my advise is to always get the best oil filter money. Figuring out what's a good oil filter is a whole lot easier actually than figuring out what's good engine oil. Just a visual inspection of the filter and its inner bits can be very telling.

Jeroen

Thanks for the revealing informtation Jeroen, quite a mind opener. Tsk1979 have very well postulated the queries that should pretty much answer the question arising in inquisitive minds.

Adding to the query, I wish to know if it is wiser to change oil filter (and not engine oil) every 5000 km when the service interval for my car is 10000 km. That effectively means two changes of oil filter for every engine oil change. Thus I stick to the manufacturer recommended oil change interval, but as an added precautionary measure, change the oil filter one extra time at 5000 km interval.

Regards

[akshay4587]

Fiat India recommends 15K interval between services,and they recommend Semi Synthetic Selenia for their MJD engines.I have heard various complaints from Average joe's(Who never look as to what is going on under the bonnet,read no oil level/coolant checks ever),that oil does not last 15K,even the coolant disappears mysteriously,and due to this i have seen quite a few engines getting rebuilt at 1L or even less no of kms on odo.

[FlatOut]

Originally Posted by Jeroen

I've participate in the past in extensive research into how engine oil affect engine life. Some basic conclusions we reached:

1 Expensive/versus cheap oil:
We found very little difference between the very expensive brands of oil and their cheaper B-brands in terms of how they affected engine wear.

2 Main contributors to engine wear:
Cooling water temperature and oil filter

A ten degree lower cooling water temperature had very noticeable (negative) impact on engine wear, notably cylinder liners and piston rings.

Improper filter technique had an even bigger impact.

So my advise is to always get the best oil filter money. Figuring out what's a good oil filter is a whole lot easier actually than figuring out what's good engine oil. Just a visual inspection of the filter and its inner bits can be very telling.

So the old better safe than sorry seems a good advise here as well.

if you search the web on this particular topic you will find two things:
- Other research will find huge differences between different oil brands
- Everybody will agree on the huge differences in filters
- You will find surprising little information on how often you really need to
replace filters (i.e. everybody does it default as part of the oil change)


My thought/advise;
I think by and large we change our oil to often/early. Never the less,
stick to the interval as stipulated in the official owner manual.

Jeroen

That's very interesting, filtration is a science in itself even if you simply regard the element, let alone the way it is pleated or the internal oil flow of a throw-away filter. I agree with the 'buy a good filter' advice. You don't mention size of filtration element - for example VW engines often have much larger oil filters than other makes. Should people be looking to fit larger oil filters where there is room? Surely size makes a positive difference?

The temperature-wear story brings up an interesting point. If it is the coolant temperature which affects wear, then since many modern engines have a coolant/oil heat exchanger to bring engine oil up to temperature more quickly (and provide a larger heat sink for the coolant), is the slower coolant warm-up at all detrimental to engine life?

As for leaving oil in engines for more than 30,000km, I would never do this. Manufacturers are only concerned with the first six or seven years of their products' reliablity. What happens after that is of little concern to them.

Everything here is assuming an engine in tip-top order - which many are not as the km and years pile on. Not everybody is fortunate to be able to afford a newish Audi or has a company car. As an engine begins to wear, there are more combustion by-products which contaminate the oil which a conventional filter does not remove. Leaving these circulating the engine for so long cannot be a good idea, in my opinion.

There is one man in Britain who is seen as a guru for motorists - for years he has been handing out superb advice in a newspaper and has spent all his life dealing with motor cars. Here are a couple of interesting pages.
http://www.telegraph.co.uk/motoring/...ny-column.html
http://www.honestjohn.co.uk/forum/po...ex.htm?t=17800

From my experience of my own engines, good quality oil is worth it. I use a premium mineral oil rather than anything labelled 'semi-synthetic'.

PS Jeroen, I forgot to ask up to what mileage you took an engine in the research?

[Jeroen]

Originally Posted by tsk1979

Thanks Jeroen. That was a very informative post.
I have a couple of questions for you
1. Some engine oils, esp for Diesel engines are advertised as "Long Drain engine oils". Are these any different than normal engine oils? Can you really use them for long drain?
2. When you say cooling water temperature, will it help if for a car that does short distances only its best to use a thinner oil. For example 0W30 instead of 15W40 if your vehicle is going to run only about 5kms max on a run?
3. My manual says 15000kms for oil change. I guess if I change oil filter every 7500, it will benefit engine more. Oil change can be done every 15000kms, right? In India you get limited set of oil filters. Normally, for a particular brand of vehicle, there are just 2 brands. Eg Delphi and Elofic.

Diesel oils are very different from Petrol oils, there is a specific thread out on the forum on this very topic with lots of very good information. I'm not familiar with the term "long drain", but I assume its similar to long life. If you take the VW/Audi TDi diesel for example, they use a very specific "diesel" long life oil. All of these cars have service interval indicators and they'll easily get you 25-30.000 km between oil changes.

On some cars (like for instance my Jaguar), Alfa and Mercedes) the manufacturer recommends different oils for winter/summer. I would stick to the manufacturer recommendation no matter how many opinions are vented on this or any other forum on the internet. I know a bit of a contradiciton in terms, but I'm sure you get my drift.

On the oil change. Our research showed that if your car manufacturer advised for instance to change the oil at 7500 km, really the oil filter needed changing, not the oil. So, to put it boldy, its not about changing your oil filter more frequently, but about changing your filter at the recommended oil change interval and leave the oil to the next interval.

One additional thing; make sure your air filter is the best money can buy as well! And change it regularly, especially here in Indai. Dust and particles have a very detrimental effect on engine oil and engine wear.

Originally Posted by honeybee

I have actually only seen one brand:Purolator.

Do a search for Purolator on youtube! Lots of video's of enthusiasist cutting them open and exposing their inner parts! Actually, by and large not a bad filter apparently

Originally Posted by Grr7

Thanks for the revealing informtation Jeroen, quite a mind opener. Tsk1979 have very well postulated the queries that should pretty much answer the question arising in inquisitive minds.

Adding to the query, I wish to know if it is wiser to change oil filter (and not engine oil) every 5000 km when the service interval for my car is 10000 km. That effectively means two changes of oil filter for every engine oil change. Thus I stick to the manufacturer recommended oil change interval, but as an added precautionary measure, change the oil filter one extra time at 5000 km interval.

Regards

See my answer above. Don't increase the filter intervals! Increase the oil change intervals. Better yet, stick to the Manufacturer recommedation. As you will find in this answer; don't believe anything or anybody's opinion on the internet. Very few, if any, have any statistical significant experience to make any suggestion whatsoever. They are just filling forum space with meaningless text, no evidence, that is significant or can be extrapolated for use at large whatsoever. Stick to the manufacturer recommendation or be more prudent and go with the better safe than sorry theory.

Originally Posted by akshay4587

Fiat India recommends 15K interval between services,and they recommend Semi Synthetic Selenia for their MJD engines.I have heard various complaints from Average joe's(Who never look as to what is going on under the bonnet,read no oil level/coolant checks ever),that oil does not last 15K,even the coolant disappears mysteriously,and due to this i have seen quite a few engines getting rebuilt at 1L or even less no of kms on odo.

Well, what do you want me to say? If you're stupid or ignorant or don't care about your engine that's your problem never mine and it can not be reflected in normal maintenance practises. My dad was like that. One night he comes home and tells me the car doesn't drive well and there is a funny red light. He'd been driving 245 km with the hand brake on. A few week laters he comes home and tells me its the same problem. Car doesn't drive well and now it also makes a funny noise and it has a little red light on. Turns out the oil pressure was low and he just pressed on. No amount of preventive maintenance, syntheitic oil or whatever is going to help these poor sods out!

Originally Posted by FlatOut

That's very interesting, filtration is a science in itself even if you simply regard the element, let alone the way it is pleated or the internal oil flow of a throw-away filter. I agree with the 'buy a good filter' advice. You don't mention size of filtration element - for example VW engines often have much larger oil filters than other makes. Should people be looking to fit larger oil filters where there is room? Surely size makes a positive difference?

The temperature-wear story brings up an interesting point. If it is the coolant temperature which affects wear, then since many modern engines have a coolant/oil heat exchanger to bring engine oil up to temperature more quickly (and provide a larger heat sink for the coolant), is the slower coolant warm-up at all detrimental to engine life?

As for leaving oil in engines for more than 30,000km, I would never do this. Manufacturers are only concerned with the first six or seven years of their products' reliablity. What happens after that is of little concern to them.

Everything here is assuming an engine in tip-top order - which many are not as the km and years pile on. Not everybody is fortunate to be able to afford a newish Audi or has a company car. As an engine begins to wear, there are more combustion by-products which contaminate the oil which a conventional filter does not remove. Leaving these circulating the engine for so long cannot be a good idea, in my opinion.

There is one man in Britain who is seen as a guru for motorists - for years he has been handing out superb advice in a newspaper and has spent all his life dealing with motor cars. Here are a couple of interesting pages.
http://www.telegraph.co.uk/motoring/...ny-column.html
http://www.honestjohn.co.uk/forum/po...ex.htm?t=17800

From my experience of my own engines, good quality oil is worth it. I use a premium mineral oil rather than anything labelled 'semi-synthetic'.

PS Jeroen, I forgot to ask up to what mileage you took an engine in the research?

As usual, it's not just about size. Its about a combination of different factors. What is really important is to what size does the filter, actually filter out contemanitions? If you google this you will get several zillions hits, so the jury is still out on that. At least on all the car forums in the world. Again, stick to the car manufacturers specifications. And be weary of cheap filters. Its cheap for a reason.

The engine temperature is indeed a big factor in engine wear. I remember as much as 10 years ago on my VW/Audi TDi Diesels during winter time; these engines are incredibly efficient and just idling them would, during winter, not warm them up at all. When it's like minus 10-20 degrees you really had to drive them for 15-20 minutes before they would reach normal operating temperatures. Some modern (diesel) engines have heaters, for quicker warm up. Also, in Scandanivian countries, and manufactures like Volve and Saab (before they went bust), had special options with electrical heaters. You would plug in your car into an electric socket on the road side and the heater would keep the engine, oil and cooling water at a reasonable temperature. So in the morning your heater would work immediately and your engine would warm up quickly as well. Get yourself to Stockholm and you will see these sockets in front of many houses/apartments!

I agree that manufacturers design their cars for anywhere between to 5-10 years. And maintenance schedules might reflect this. Although I have yet to see evidence of that. I've only seen lots of opinions. Having said that, if you do buy new cars regularly you really don't have to worry about oil changes at all. The real problems won't occur before the car gets to be 15-25 year old and or has done well over 200K km. Assuming it more or less gets its recommended maintenance during that period.

So, for all those new car owners, all your preventive maintenance and the associated cost you're committing to is very much appreciated by the likes of me who would never ever buy a new car privately, but will only buy second hand 5-10 years old, at least 100-150K on the clock, thank you very much!

I don't know how you quantify you're own experience as being worth it? I would say when it comes to oil, personal experience is really a none issue, because there is simply no statistical relevance whatsover. Still, it fills this any many other car forums with lots of text and so called experiences. To me, it just illustrates a total lack of understanding of the topic at hand.

Unfortunately, the truth is that you, or any private owner and most garages and dealers experiences simply put, have no relevance. When it comes to this topic you need to take a holistic view and have a real significant set of at least empirical data. To suggest that any of us, based on our own experience with our own cars and oil, has any relevance shows a total lack of understanding of the topic at hand. It is just way to limited to be significant for this very complex phenoma that occurs over a very long period of time and or miles/kilometres.

I said it before; A man needs to understand it's limitations. (See also ClintE)

You are correct in saying that filters are not a cure for contamination due to combustion by products. But oils and in particular modern synthetic oils are extremely good at that. Other than lubrication and cooling, that's what they are designed to do; keep the contamination at bay! They are designed in such a way they will actually 'encapsulate' these sort of contaminations so they have no negative effect on engine wear. Obviously, there is a limit to how much they can absorb. But it's much more then we tend to believe or tend to read on the internet. But again, the old "better safe than sorry" does hold true here as well.

The "research" is a little bit more elobarate than just take one engine apart after a certain mileage. In fact, this particular research was a combination of new engines that were put through long duraction simulation. (we're talking several weeks of 24/7 simulations) as well as looking at several dozens of engines with different mileage. This research took place over approx 14 months, and several European countries. Again, as pointed out earlier, you need a lot of data to make any statistical significant conclussions.

I was part of the research and program on the marine diesels. Although we more or less designed the program ourselves we engaged the support of a well knonw and very reputable European Research fascility. They helped us validate the testing methods and results. They were at the same time conducting the test on car engines, so we did compare a lot of notes so to speak. And we actually adjusted some of testing vice versa to validat some of the results. So I got a bit of insight in car engines as well.

Mind you, all of this took place some time ago. Since then a lot of progress has been made with respect to lub oil and engine production. New production techniques have led to far more precise and smaller tolerances in components and subsequently lubracting has improved considerably.

We think of lub oil in terms of 'preventing wear and tear 'of the engine. Which of course is true. Even so, lub oil and lubrication and all of its properties is just one of the many parameters in engine wear.

We had a case of several of our Werkspoor TM410 Diesel engines suffering from badly damaged bearings. These are medium speed, four stroke, in our case 6-8 cilinder diesel producing 4000 -5500 HP. Initial thoughts were all to do with lubrication, untill we found out it was actually a balancing problem and how the engines got used. Mainly extensive periods of relatively high rpm at low loading which led to problems in the bearings and actually tore some of the engine base plates apart as well. So when people want to discuss the beauty of the perfect balanced engine, say a boxer or "flat engine" or so it just makes me crinch.

It really shows a complete lack of in depth understanding of what makes an engine work well and reliable for years, and or thousands of hours on many thousand of miles. These engines never vibrated, untill they actually threw their bearings and we had to face repairs of literally million of dollars per engine. On top of that these anchor handling tugs were out of commission for several weeks too.

Just because an engine is theoretically well balanced and runs on the best oil money can buy doesn't guarantee it will last for ever. Or is a superb design for that matter.

Based on my own experience with these hugely costly repairs I hate to rev engines unloaded. No matter what. I'm always very surprised to see the engineers in F1 reving these very high performance engines right up to the red lines. So, much to learn and to understand. I would love to spend some time with some F1 engine specialists on getting their thoughts on lub oils, balancing and engine wear and performance. Let it be understood, I have no experience whatsoever on F1 engine design whatsover, It's just a gut feeling. Real or not, I don't know.

So, again; don't take any notice of anything on the internet when it comes to oil changes, other than the above. Trust me!
The essence is: Stick to the manufacturers recommendations, or if you want to be bold, be safe and do it more often.

Here's how I do the oil and oil filter changes:

I more or less stick to the manufacturers recommendations. But I do round it up, upwards. So I don't get uptight if the schedule says every 5000 km and for practical reasons I can't do it untill 6000 km. Or even 7000 km. I do buy the best oil filter I can get. I buy cheap lub oil, but with the correct specification in accordance with the manufactures requirements. I also install the best air filters I can get. Usually K&N. The ones that you can clean and not the throw away ones.

Enjoy that car, don't worry to much about the lub oil. If you sell your cars on, you're only worrying about something that might, and I really mean might, be of relevance of future owners!


Jeroen

[FlatOut]

I think that what Jeroen is suggesting is that lab research is what he uses as his template for how he treats his cars and their running gear.

I read new research and take it onboard, quite often it reflects what people have learnt for themselves in the real world. Anyone I know who understands engines knows the last thing you should ever do is rev your average car engine at steady high revs for prolonged periods under low load. (If fitted with an automatic gearbox, it could destroy this within a few minutes.) In some this is intuitive, they would just know it would be bound to cause problems! You can teach most people to play a musical instrument to a high standard, but only a smallish percentage may have a natural musical ability and will make it 'sing'. Same for many other talents in life - some are naturals, others succeed by persistance and force.

Having digested what people in laboratories have found, I translate this for the real world which is so very different from a lab. Jeroen's point about air filtration is a very good one - some of the smallest, sharpest particles reach the cylinders before oil has chance to capture them. The same goes for fuel. It is sub-micron particles which are the hardest, sharpest and most abrasive. These are also generated by combustion and accumulate with use in the oil.

Many of the cars I have owned and used hard down the years have covered over 200,000km and the engines still work well. Their servicing has usually been to manufacturers' recommendations. Of course, if an engine had previously worn it would have been replaced/repaired or the car scrapped. Well-designed and correctly serviced engines should easily last beyond 200,000km.

In my experience, an engine is more likely to fail or wear prematurely when used with oil which is well past its best. How do you know this? Some can make a rough judgement by feeling and smelling the oil and by engine performance, most cannot. Without having oil samples tested, you have no idea if at 25,000km your oil is still doing its job correctly. Oil does a lot more than lubricate and combat acidic combustion by-products. It cools an engine too, to a far greater extent than many people are aware. Extended use of old oil may be fine in a newish, low mileage engine, but as age and miles increase it places more stress on aspects of an engine which aren't just lubrication-related. The older/higher mileage an engine and the harder an engine works in adverse conditions, the more frequently servicing may be required for continued operation without unnecessary wear. Just as there is less chance of a 20 year old's body being damaged in intensive hard exercise than a 60 year old's, even if both are in good health with high levels of fitness. Many prefer not to take a chance and recognize that oil and filters are a lot cheaper than an engine, its components and repair.

Sometimes manufacturers make mistakes. In the 1990s, PSA (whose diesel engines are used by Jaguar Land Rover) stretched their oil change intervals for their diesel engines to keep up with the competition (regarding lack of servicing) and conrods started to punch through blocks as mileages grew. Those who changed their oil at the old limits didn't suffer any failure. They upgraded bearings to cope, if I remember rightly.

Questions which remain unanswered - is slower coolant temperature rise detrimental even when the oil temperature rises more quickly (as with engines with oil-coolant heat exchangers) or is rapid coolant temperature rise and slower lubrication oil temperature rise (as happens without these HEs) preferable? It sounded as if the latter might be better for wear, from what Jeroen was saying.

Is a large filter better than a small one of the same quality? I've wondered why VW/Audi/Skoda engines often have relatively very large oil filters fitted, compared with similar engines.

[Jeroen]

Originally Posted by FlatOut

I think that what Jeroen is suggesting is that lab research is what he uses as his template for how he treats his cars and their running gear.

Many of the cars I have owned and used hard down the years have covered over 200,000km and the engines still work well. Their servicing has usually been to manufacturers' recommendations. Of course, if an engine had previously worn it would have been replaced/repaired or the car scrapped. Well-designed and correctly serviced engines should easily last beyond 200,000km.

Questions which remain unanswered - is slower coolant temperature rise detrimental even when the oil temperature rises more quickly (as with engines with oil-coolant heat exchangers) or is rapid coolant temperature rise and slower lubrication oil temperature rise (as happens without these HEs) preferable? It sounded as if the latter might be better for wear, from what Jeroen was saying.

Is a large filter better than a small one of the same quality? I've wondered why VW/Audi/Skoda engines often have relatively very large oil filters fitted, compared with similar engines.

Just to clarify: it wasnt really lab research. The marine diesel test program was carried out over a period of more than a year on our fleet of ocean going and anchor handling tugs. The condition under which those engines and oils were used were very carefully monitored and in some cases controlled. E.g run at lower coolant temperature, change the way we filtered etc. we just took these engines apart a lot to take the various measurements of wear and tear.

The car research did involve running some test bed simulation, including tests/verification with data on engines used in real life.

Id say that the slow rising cooling water temperature is the main factor. Even if the oil is warm, if the engine block and more importantly the cylinder liners are not yet at the correct temperature, the lub oil will simply work suboptimal. In order to provide the designed lubrication characteristics it needs to be applied to a surface with the correct temperature.

Large isn't the criteria perse. AFilter needs to comply with at least three criteria:
It needs to filter to a certain specified size of particles. It also needs to be able to accommodate a certain oil flow. And it needs to last a certain time. That is a question of volume. Once a filter is correctly specified making it larger might make it last longer perhaps at least in theory.

The outside dimensions are rarely a good indicator of the actual filter size. Check out those youtube videos again of the filters that get cut open! Its one way of producing a filter cheaply. Have less filter material inside.

The problem with the bearings was partly a design and partly an operational problem. These tugs have variable pitch propellors and in combination with the way they are operated will by sheer definition require extensive periods of idling at relative high RPMs.

Jeroen

[HillMan]

IMO a larger filter should not make a difference to the engine oil performance. The engine manufacturers spend lot of time and money in research. That shows on the reliability of their machines based on the number of miles they make before end of life.

Larger filter or smaller, it has to be changed during oil change. If it can last a year or manufacturer recommended miles, that good enough. Filters can only capture solid particles floating in the oil, which is generally caused by friction of metals.

Over time additives in the oil like detergents, dispersants, rust-fighters and friction reducers will wear out, so the oil won't lubricate as well as it should. This has direct affect on the performance of the oil as time progresses.

We do not know the engine better than its manufacturer. Like people, every engine has its personality and so oil change intervals cannot be generalized. Some manufacturers have come up with logic to find the oil change interval and put up service warnings. Nissan has mechanism to check quality of expensive gear oil in its CVT so they dont have to change often. But for others without concrete data and testing tools, it is better to stick with manufacturer guidelines. At least technology has improved the shelf life of oil which used to expire in a year earlier if left alone in the engine and needed annual change.

If you plan to keep engine oil for longer duration, check the oil manufacturer recommendations for the pack. For me, I'd stick to the service catalog from manufacturer.

VW spec oils must still meet the spec after 5 years in a sealed container or 3 years after opening - whichever comes first.

Life of engine oil:
Unopened in factory sealed container stored indoors = 60 months
Unopened in factory sealed container stored subjected to freezing = 24 months
Once opened and air introduced = 12 months.

Source:
http://www.bobistheoilguy.com/forums...Number=1703349
http://www.briskoda.net/forums/topic...ts-shelf-life/

[Sutripta]

@Jeroen,
Any views/ opinions on using TAN/ TBN as a guide to oil changes for medium size (20000cc - 40000 cc) diesels?

The controlled tests: Any of these engines without a roller cam follower? All crosshead piston designs?

Would be interested in knowing how the source of the bearing failure was arrived at. Forensic examination of bearing (fatigue failure?)/ correlating with major operating mode => leading to reexamination of all design calculations?
These were tugs, or off shore/ oil platform supply and support vessels? Who bore the cost? Of actual repairs. Of loss of profits.

Regarding balance and forces, I was just thinking that we are lucky that in India we don't have mainstream engines with balance shafts (except for a few motorcycle engines). So thankfully no balance shaft discussions here. (Going by what I see written about balance shafts in a few foreign forums, these discussions would have driven you up the wall!)

Regards
Sutripta