Comparisons between HGVs, vans and cars are not really viable.
My lad drives fuel tankers and they work 24/7 and the engine and oil never get cold.
In comparison my wife potters about town and often a week will go by without it ever getting anywhere near operating temperature.
Why are car makers continually extending the mileage. Is it a marketing ploy or has there been great moves forward in engine or oil technology?.
Its not that long ago that Vauxhall stipulated 4500 oil change intervals so what has happened for them now to be saying 20000.
Personally I believe its a bit of both and probably its OK for a rep or similar who is clocking up big mileages but not for the ordinary man driving a few miles into work every day.
I still change the oil every 5000 miles and as its such a cheap part of motoring costs will continue to do so.
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I've raised this a number of times. My query was why some manufacturers dictate a completely different oil change regime in the US as compared to the UK for the same car. Volkswagen and GM are some examples. They do not offer the long-life regimes in the US. A 2006 Passat requires a change at 5k, 10k and then every 10k. If you take a look at some of the US forums, there is an almost manic desire to change the oil at 3000 miles or less and many send a sample off for analysis before then. 5000 miles is regarded as reckless on the vwvortex forum. The usual answer I get when I ask about the difference is that there are cultural differences. Not sure that answers it for me. I suspect that the true reason is that manufacturers do what they can get away with in different markets. The UK market is driven by company/lease cars and long service intervals are attractive to them.
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Also, the US fuel has only recently begun the change to ULSD, which may well explain why VWoA is reluctant to sanction extended oil change intervals. but, more likely, it inhibits dealer cash flow. And given the US propensity to experiment, they ignore VW oil recommendations and substitute an unknown quantity, available more readily.
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> I still change the oil every 5000 miles and as its such a cheap part of motoring costs will continue to do so.
Tend to agree with this. When an oil change costs as much as around 200 miles' worth of petrol, every 5000 miles doesn't seem excessive.
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"The UK market is driven by company/lease cars and long service intervals are attractive to them."
I suspect that the engine can go to hell in a handcart after the typical lease period is up, as far as Manufacturers are concerned.
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I do agree that it would be interesting to see some research about component wear for modern engines and lubricants. I've always done it 6-monthly (5000 miles) using synth or semi-synth oil out of habit but could be persuaded otherwise with some decent evidence. I wonder what proportion of engines ever get to 150k or 200k. I guess that it's only then that the damage caused by long-life servicing becomes evident.
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"And given the US propensity to experiment, they ignore VW oil recommendations and substitute an unknown quantity, available more readily."
Yes, thats been evident on the TDI forum, quite amazing that people would use their favourite oil that did not meet VW`s spec for the unit injector engines. Also there is a tendency to `mix weights` ( their term) .....
Re longlife servicing, It would be so easy to check it out by popping a few cam covers..... IMHO its not going to happen though, I suspect we have entered an era where only a few of us care and `Joe Public` hasn`t a clue about oil and the engine, let alone concerns over extended oil changes.
Regards
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"I've always done it 6-monthly (5000 miles) using synth or semi-synth oil out of habit but could be persuaded otherwise with some decent evidence."
Me too, What makes it so frustrating is that the *evidence is already there* under the cam covers and in the service books. IMHO it just needs
a largish sample of cars to rule out the odd rogue result, cam lobe wear and cambox cleanliness giving a representation of wear in the engine under extended and normal oil change intervals.
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I'm not sure that cam wear is enough evidence for me. I've got a 1.8t Passat. What about the bottom end, the cylinders, the valve guides, the timing chain, the turbo bearings.....
I've seen examples of motorbike engines stripped down by magazines in the past. I thought that was a good idea.
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I admit to being concerned by these long service intervals. I have recently bought a BMW 330Ci 'vert and as such the service intervals are governed by the obc which I understand monitors driving style and also the quality of the oil. BMW recommend Castol SLX fully synthetic & I read somewhere in all the blurp that if you top up with say a mineral oil then the sensors will detect this & shorten the service interval.
BMW state that 15k intervals are about average although this may shorten or lengthen depending on driving style.
The time limit for low mileage is every 2 years --- this is stated in the service schedule,
Whilst I still feel uneasy about this, there are loads of high mileage BMW's on ebay (100k +) that have BMW FSH at intervals of approx 20k.
My dilemma is - Do I accept BMW's schedule which is all I need to do to keep the warranty in place or do I have more frequent oil changes and pay through the nose for this security, which may be unecessary anyway.
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Have a look through the technical matters forum.
There's a vary large number of cars that have been on long life service intervals now on the roads, many still doing serious milage.
I can't remember the last thread I've seen about cam lobe wear, big end bearing changes or any other issue that would have been caused by insufficient oil changes.
Its MAFF or Lambda sensors, fuel pumps and common rail issues, brake and suspension issues but NO wear due to oil issues.
That's sufficient evidence for me that long life oil changes aren't going to stop the engines outlasting the rest of the car.
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I read often, only post occasionally
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>>My father used to change his cars' oil and filter every 3,000 miles, so just be thankful.
STUARTLI.......Did he by any chance have a black Rover three litre at the time?
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"I'm not sure that cam wear is enough evidence for me. I've got a 1.8t Passat. What about the bottom end, the cylinders, the valve guides, the timing chain, the turbo bearings....."
Sure, I take your point on that, but I thought cam lobe wear and cleanliness in that area was easy to do, no stripdowns.
Also that cam lobes were the first to suffer re oil related engine wear.
If its a full strip down (IMHO) its not going to happen in numbers, while a mech could examine the cam area on several cars in one day, at relatively low cost for the organisation paying for it.
For example, Which gives more confidence, Mobil`s million mile test on two cars under track conditions and a full stripdown, Or 100 cars in normal use having their cam lobes measured along with evidence of sludging in the cambox?
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As someone says more than once in this thread, unless some proper research is undertaken then we'll never know.
To me, the single biggest factor in engine wear must be how you use the car. A multitude of cold starts, short journeys and plenty of damp air and condensation ain't gonna be much good, whereas a regional sales rep driving hundreds of motorway miles in one go or several times a week will be putting less strain on the oil.
As cars age I think we worry too much about oil quality. Surely we should be more fearful of the auxillaries packing up on us overnight: alternators, batteries, pumps, belts, hoses,...? Sludgy oil is unlikely to leave us stranded at the side of the road is it?!
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"To me, the single biggest factor in engine wear must be how you use the car"
I agree, Look at Mobil`s million mile test of Mobil 1, ideal steady running conditions on a track. Even then, they did 7,500 and 15,000 oil changes, not 20,000 as is typical with (for example) Vauxhall cars under `road` conditions..
Given that road conditions are more severe on an oil than constant track cruising,
I wonder why they did not up the oil change interval and why they seemed to hedge their bets with one of their cars running only 7,500 intervals?
I wonder if in regular stop start, cold running road use that 7,500 figure translates to 5,000 changes?
Sure, speculation on my part, but where does that leave us with 20,000 2 year oil changes?
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spikeyhead - I agree with your post entirely - but most peoples heads are in the sand on this issue. If long-life servicing were as bad as people claimed every other post on technical matters would be about repairing engines damaged by lubrication failure - when, as you say, these types of posts are quite rare. This is exactly the evidence that people on this thread have been asking for, and there's no need to even take of cam covers to see it.
Of course, regular oil changes are a good thing, but I wouldnt be put off a second hand car that had been long-life serviced, as long as there was evidence that the servicing had been done when required, and using the correct oil.
I would suggest that those intending to get the best life out of their car would be better off asking about how best to rust-proof the known weak spots on their cars' bodywork, and how to get the best life out of the transmission and electrical parts.
Number_Cruncher
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I would suggest that those intending to get the best life out of their car would be better off asking about how best to rust-proof the known weak spots on their cars' bodywork, and how to get the best life out of the transmission and electrical parts.
You've prompted me to ask a question I've been meaning to for ages. On cars with known electrical foibles (Peugeot, Alfa, etc) a lot of reviews on the net always say 'Just make sure you get it serviced and it will be OK' and things along those lines.
I just cannot think of what a service would do to help prolong the life of the electrical system, besides fixing any faults that have already occured, or maybe replacing a dodpy looking multiplug if they happen to spot.
I can't think of any way that the electrcial system could be 'serviced' per se.
Am I right?! Also, is there a way to prolong the life of the electrics? I can only think not leaving the heated rear window/other high current devices on all the time. Other than that...
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"but most peoples heads are in the sand on this issue. If long-life servicing were as bad as people claimed every other post on technical matters would be about repairing engines damaged by lubrication failure - when, as you say, these types of posts are quite rare. This is exactly the evidence that people on this thread have been asking for, and there's no need to even take of cam covers to see it."
Writing as the OP for this thread,
I don`t know about "heads in the sand" it seemed a reasonable topic for debate, I have not said long life servicing is bad, but rather enquired into it,
only attempting a discussion.......................
But what you describe is not `evidence` , you need a micrometer and a direct examination for that. There `may` be many slightly sludged engines with wear caused by extended service intervals that no one is aware of.
I am quite confident that the manufacturers have done their sums to the extent that there will not be major failures due to extended oil changes but what are the wear levels, at say 150.000 miles?
Regards
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Extended service interrvals (imo) are very bad not just for the engine.
I firmly believe that they are specified for fleet managers etc and to promote lower servicing costs for ordinary buyers too. Very unlikely an engine will fail before its warranty expires if servicved to high mileage schedules. But that is not the same as wanting long life fromn the engine, which will affect the buyers via 2nd hand values dropping because of poor or "perceived" poor servicing.
But the high mileage only affects other parts of the car too, brakes, suspension, steering, cooling, leaks etc. I personally would prefer cars to be serviced/inspected more often not less but I do look at a lot of cars and see the average condition; not just that of a well cared for one !
But I agree some "proof" would be better for all to see/read etc. And what a relevant, easy, simple topic it would be for a decent motoring magazine. And most wear will show at the top end before problems happen at the bottom end ! So I agrree with the simple idea of cam cover inspections !
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Surely service schedules would require inspections of other components like brake pads more often that every 20,000 miles? Otherwise the owner will end up paying for changing part-worn pads. The garage will know they'll not see the car for another 20k miles so the pads would be changed as a matter of course. Or do they rely on warning lights etc to tell you your pads are worn?
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>>There `may` be many slightly sludged engines with wear caused by extended service intervals that no one is aware of.
If no-one is aware of it, then, it **isn't** a problem. If it isn't a problem, then, IMO, it isn't something to worry about.
By talking about heads in the sand, I'm on about the sort who automatically thinks longer service intervals are bad for the engine. They aren't prepared to accpt that engine oils and engine materials are better than they used to be.
I wasn't attacking your starting this thread in any way - actually I think it's a very good question, but probably, for different reasons. IMO, the real value of the service isn't the oil & filter change, but, the time spent by a skilled person checking over the rest of the car - for many cars, it's probably the only time outside the MOT station where lights, tyres, wipers, horn, and brakes are properly checked, and I find the logic for extending these inspection intervals (especially if a 2 year MOT were introduced) quite dubious, and potentially unsafe.
Number_Cruncher
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"If no-one is aware of it, then, it **isn't** a problem"
Really? Do you know the state of your coronary arteries?
Oil doesn't just prevent wear, it disperses heat and contaminents, which is why sludge is a problem. Worn cam lobes are more often the result of a blocked oilway than direct wear because the oil was 'worn out'. Frequent oil changes are a cheap and simple prophylactic measure, so why not? I seem to recall that the guy with the 2-million mile Volvo P1800 changed his every 3k...
FWIW, I do accept that oils and metallurgy are better than they were - just not that much better!
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>>Do you know the state of your coronary arteries?
Given their service history, I can guess that they might not be tip-top!
However, we are talking about engines. If engines were failing and giving people big bills, there would be post after post in technical matters. When I catch up with old colleagues and ask if they have been doing any interesting work - they say not, no engine jobs or anything meaty, just lots of servicing, brakes, suspension, and electrical jobs. Until you are firmly into banger territory, lubrication based engine failure is rare - IMO, there are more pressing things to worry about.
Number_Cruncher
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-FWIW, I do accept that oils and metallurgy are better than they were - just not that much better!-
Also build tolerances have improved,a better fit at the start of the engine's life must add to longevity.I have some early fifties editions of Autocar magazine,back then rebuilding an engine at 30000 was taken for granted apparently.
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>>I have some early fifties editions of Autocar magazine,back then rebuilding an engine at 30000 was taken for granted apparently.
Rebuilding a Cortina engine in the 60s/70s at around 50,000 was pretty much accepted as well.
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But what you describe is not `evidence` , you need a micrometer and a direct examination for that. There `may` be many slightly sludged engines with wear caused by extended service intervals that no one is aware of. I am quite confident that the manufacturers have done their sums to the extent that there will not be major failures due to extended oil changes but what are the wear levels, at say 150.000 miles? Regards
Of course it is evidence. If someone hears a lot of gunshots and finds a body full of holes then that's evidence that the body's been shot. It not conclusive proof though.
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I read often, only post occasionally
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>>You've prompted me to ask a question...
Of the top of my head, I suppose I was thinking of things like, repairing oil leaks, where the oil is flooding the alternator - changing brushes before they begin to arc, meaning you save the cost of a new starter or alternator - changing brake fluid to prevent costly ABS valve block problems - repairing known water leak problems where the water ends up soaking the ECU - dealing with known troublesome ignition coils which can damage the ECU via electrical interference.
Number_Cruncher
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Of the top of my head... Number_Cruncher
Good answer!
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"or do I have more frequent oil changes and pay through the nose for this security"
You only have to pay through the nose if your dealer does it. Why not have the extra changes done by, say, National Tyres, for £20-25?
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">work 24/7 and the engine and oil never get cold.<"
That's the important bit, cold starts and short trips cut oil life and engine life. Mundane cars can reach monster mileages as shared cabs,
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In the USA, there have been many claims against VW of America and Audi, for sludged-up 1.8T engines fitted to Audi TTs, Passats etc... These have had oil in the sump turn to thick black sludge and engines and turbochargers fail catastrophically.
I have not heard of this here, so maybe we just shut up and put up, or we use better oil, or our operating mode is more sympathetic?
"I've seen a few cases," he said. "It seems to happen mostly when we can't verify oil change history, when people don't do them for 20,000 miles. I think that this is a problem that is pretty broad in the industry right now..."
www.autosafety.org/article.php?did=963&scid=122
"It was only a question of time, right? A national class action case has now been filed against VW for the massive turbo sludge failures in its 1998-2004 longitudinal mount 1.8T....."
www.passatworld.com/forums/showthread.php?t=225417...e
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Rule number 1 with any performance turbo engine: give it a good thrashing, trolling along at 55, 65 or 75 will cause problems.
Rule number 2 with any performance turbo engine: it's wasted on the average lard-backsided Yank. And the obese Brits.
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Ashok, you've picked up on a thread I raised a while ago but which didn't get much interest. Oil sludging does seem to be a big issue in the US for many manufacturers (including VW, BMW & Toyota) but I was unaware of much evidence of it over here. The vwvortex forum is full of posts about sludging and oil recommendations.
What perplexed me was that oil sludging is happening to such an extent despite the conservative oil changing regime in the US. The VW USA servicing schedule has been about 1/2 (i.e twice as frequent) of the European one for many years. I find it difficult to believe that our operating mode is more sympathetic. Oil quality was raised as a possibility but I wonder why US drivers would be more concerned about frequency of oil changes than the quality of the oil used. Fuel quality is another possibility as US fuel has high levels of sulphur. I remain perplexed (with many things...........).
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The US had problems with the oils routinely used over there, with low resistance to heat and thus oxidation. Many dealers reportedly used oil suitable for low stress usage, i.e. the old large capacity V8s with little power ouput per litre, ignoring VW advice. Low cost bulk oil unable to resist higher stress. Whether OCI at 3000 or even 1000 miles would make little difference.
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Every vehicle manufacturer wants their products to have as good a reputation as possible. If they specify 20,000 mile oil changes then they'll have carried out enough durability tests to give them confidence in this.
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L\'escargot.
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L'escargot, I admire your confidence but, contrary to your logic, why did Daimler Benz throw away their reputation for quality product a few years ago? Many industries seem to follow very short-termist strategies these days. I fear that headline cost-cutting comes at the expense of long-term strategy. I blame the management consultants....... and the marketing consultants......and the accountants...........
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L'escargot, I admire your confidence .........
It's based on the experiences of a working lifetime in automotive R and D.
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L\'escargot.
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Interesting how much information is around on this subject but very little from actual inspections inside engines.
From my experience of looking at engines its a relatively cheap way to ensure good life from your engine, ie regular oil and filter changes. The warranty and lifetime required by the vehicle assembler is not necessarily the same expected from the owner of the car. If you are buying brand new and selling at 2 or 3 years old then all this oil talk is irrelevant but if you are keeping the car for up to 10 years or more it becomes more important.
There is no reason why most modern engines will not cover 250,000 miles plus quite easily. But very few make it there. Tell me why if you want, I have my own opinion b ased on experience of servicing, repairing, dealing with cars at the sharp end.
This year alone (2007) I have personally seen 5 engines at the end of their premature life so oil problems (quality, cleanliness, lack of oil etc ) do exist ! Not a lot in the amount of cars I have seen I agree, but for each owner its a big problem !
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There is no reason why most modern engines will not cover 250,000 miles plus quite easily. But very few make it there.
I firmly believe that a lot of the reason "Premium" brand cars are accepted to be better at high mileages than say a Ford or Vauxhall is because the higher values of the premium cars mean owners are more likely to keep up proper maintenance. A typical 5 year old petrol Ford Mondeo with 100+k on the clock will be worth about £2k. A similar BMW 3 series may still be worth £8k+. Which car is likely to benefit from more consciencious maintenance?
I proved very early on in my driving career that a Ford Pinto engine can cover 185k on its original camshaft without even a hint of surface scoring on the lobes, when many experts said the cams in these engines tended to be shot by 100k. The answer I suspect is maintenance. Mine had oil changes every 3-4k religiously and on it plodded, yet many others were clattering and smoking with half this mileage. Yet in my late teens, I didn't understand the term "gentle driving" so this particular engine certainly worked for a living.
It's when an engine ages that regular servicing becomes even more critical, yet values mean it's usually the complete opposite. I wonder how many of these knackered engines you talk about were running sweetly when they came off a fleet only to be dead within a few short years, and a fraction of the overall mileage covered?
Cheers
DP
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It's a matter of faith, not evidence. Some people pray in the belief that they will go to heaven. But no one knows whether they really do - everyone else seems to too, or at least they go somewhere.
I change my oil frequently because I like the feeling of security it gives me in a bad world, surrounded by lots of things I can't change. No one has yet said it does any harm, and it is cheap.
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The fact that older cars suffer from neglected maintenance makes a mockery of those claims that big 4x4s are greener because they last 20-30 years....
madf
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A colleagues Nissan Pathfinder is on fixed 18,000 mile oil changes. Seems a long interval for something used for private short journeys. He had the oil changed early, still in warranty, at a Nissan dealer and was charged over £100.
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I wasna fu but just had plenty.
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If the internet has been invented would we have had this discussion when intervals went from 3,000 to 10,000? It's called progress.
If you know you are keeping the car for decades change the oil every week if you want. My car goes after three years max - if I only need one or two services in that time I'm very happy.
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If the internet has been invented would we have had this discussion when intervals went from 3,000 to 10,000? It's called progress.
My thoughts exactly.
In the past I've certainly had cars which had a recommended oil change interval of 3000 miles. 30 nipples were scheduled to be greased every three months, and plugs and points scheduled to be adjusted every couple of thousand miles. Plugs lasted 5000 miles at the most. The recommended interval for changing the plugs on my current car is 30000 miles, with no checks/adjustments scheduled at all! My car gets what the handbook says, and no more. I've better things to do than tinkering with cars unnecessarily.
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L\'escargot.
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The recommended interval for changing the plugs on my current car is 30000 miles, with no checks/adjustments scheduled at all!
I beg your pardon, it's actually every 37,500 miles!
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L\'escargot.
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The recommended interval for changing the plugs on my current car is 30000 miles, with no checks/adjustments scheduled at all!
The difference between oil and plugs is that plugs don't need topping up! The manufacturers are assuming (or have at least covered their legal backsides by recommending) that owners will keep an eye on their dipsticks. In practice, the sort of people whose only interest in maintenance is to take their car to the dealer at the specified interval may well be turning up with half-empty sumps...
Forgive the cynicism, but IMO the manufacturers are only interested in satisfying the original purchaser/warranty holder, and have presumably made a calculated judgement that 20,000 miles is do-able. It looks good in the brochure too, and marketing men are very rarely engineers. After all, their primary objective is selling new cars!
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"Interesting how much information is around on this subject but very little from actual inspections inside engines."
Well said Yorkie, lets have evidence of a standard that would stand up in court :)
So who`s going to crack open a cam cover on a 100,000+ long service interval, ex fleet car and post a link to some photo`s?
Regards
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>>If they specify 20,000 mile oil changes then they'll have carried out enough durability tests to give them confidence in this.<<
I do not actually believe this - I think it is true up to about 3 years and 60K miles - after that, like it is said above the manufacturer does not care.
As an example - take Honda - probably the best engine manufacturers in the business and they still quote 9 or 12.5K max between oil changes. They also state interim oil changes for regular short journeys.
IMO they put longevity and engineering reputation 1st knowing it gives them loyal customers rather than damage their reputation with engine failures as a result of a variable service regime.
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But Honda do not specify the same spec oils as VW, Mercedes et al. High mileage users like taxi drivers could knock up 60,000 in a year, so I really doubt that manufacturers have a low mileage life designed in: aand there is no evidence of a problem with the VW engines if the correct oils are used.
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... rather than damage their reputation with engine failures as a result of a variable service regime.
q? - so how many manufacturers have damaged their reputations as a result of variable service regime?
answer - none, not a single one.
i really don''t know why anyone who want to change their oil at 3,000 or 5,000 or 10,000 or 20,000 or 30,000 miles, or whatever interval takes their fancy, should really care at all about what other people are doing to their engines.
if you are really bothered, change your oil frequently - why not after every trip if you wish? as "the growler" used to say, why are some motoring folk so anally retentive about oil quality and oil changes?
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why are some motoring folk so anally retentive about oil quality and oil changes?
Probably the same reason why some people such as yourself feel the need to be retentive enough to respond in a such a way.
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>>answer - none, not a single one.<<
Unfortunately VAG suffered bad oil/engine problems in the US where warranties were longer than that in the UK.
VAG oil changes in the US are 10K max - same engines as in the UK so why the difference ?
IMO it's because the US is not dominated by company cars and they have not got fleet managers to please but do have to please Joe Public who probably keeps his car longer than the fleets in theUK.
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Sorry my mistake - oil changes for VAG cars in the US are 5K miles - not 10K using castrol Syntec.
So if the engines (as sold in the UK) are durable enough to go 20K plus - why does VW not steal a march on the competition and offer this huge competitive advantage ?
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As has been said already, the main reason for these long intervals is cost -- the cars with the cheapest servicing will be chosen by fleet managers.
Well that's fine, but used car buyers should also consider cost, and perhaps buy those cars which have been serviced at more regular intervals, if they feel strongly enough about it.
If enough people refused to buy a car with a 2-year/20K servicing interval, the residual value of these cars would suffer and it would force fleet managers to think again.
I wouldn't buy a 3 year old car that'd only had one service in its lifetime, even if it ran well. Too risky for me I'm afraid. Others may disagree, in which case feel free to take the gamble.
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I agree exactly - you pays your money and you takes your choice.
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As has been said already, the main reason for these long intervals is cost -- the cars with the cheapest servicing will be chosen by fleet managers. Well that's fine, but used car buyers should also consider cost, and perhaps buy those cars which have been serviced at more regular intervals, if they feel strongly enough about it.
The lines have blurred slightly in recent years since Uncle Gordon decided to add company car drivers to his growing list of cash cows. Many company car drivers now opt out and take allowances, and now many "private buyers" are factoring in those same service costs alongside the finance or leasing costs when they are choosing their cars.
This has put the mainstream brands under a lot of pressure. Few fleets offer BMW's, Mercs and Audis even for more senior staff these days, so faced with a free choice, many people opting out will stretch their allowance to get into a basic 3 series or C-Class. The effect this has on the Fords, Vauxhalls and Peugeots of this world is plain to see. Extended servicing seems to be one way the mainstream companies are looking to tempt these user choosers back into the fold. Now they can't dump hundreds of their cars onto fleets to be given to people who don't have a choice, and faced with a level of consumer badge snobbery that seems almost unique to the UK, they have to do something. Especially when thanks to lower depreciation you can lease an entry level BMW 3 series for the same monthly payment as a mid spec Peugeot 407.
I tend to agree that there are factors other than sound engineering principles at work here.
Cheers
DP
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>>If they specify 20,000 mile oil changes then they'll have carried out enough durability tests to give them confidence in this.<< I do not actually believe this - I think it is true up to about 3 years and 60K miles
Manufacturers carry out extended durability testing on engine test beds. From the point of view of engine durability testing the relevant parameters are the load cycle and the test period. Car age doesn't come into it.
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L\'escargot.
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........ the relevant parameters are the load cycle and the test period.
Perhaps "duration" would have been a better word than "period".
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L\'escargot.
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