.... is a term sometimes used in ads for secondhand cars to indicate that the engine's not knackered. But with service intervals of 10,000 miles or more these days surely the oil cannot possibly retain anything like as much of the protective qualities needed from service to service.
I prefer an engine to use some oil and require several top ups between services. Then I know that at least some of the lubricant will be 'fresh'. Discuss...
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Mine doesn't use any oil so I do my own intermediate oil/filter change at 7.5k, the service interval being 15k. Personally I'd prefer a used car that uses no oil over one that does.
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I have had three petrol-engined VWs in the past 12 years, two Jettas and a Bora.
The first Jetta, a 1.3, had covered 66,500 miles when I got it; the second, a 1.6 TX, 52,400 miles when I purchased it and the Bora, a 1.6, 46,500 miles when it came into my possesion 18 months ago.
None of them have used any oil between oil and filter changes and I have never had one leak even the slightest drop of oil onto my light grey coloured flagstones front garden area.
Ironically, the Bora manual states that up to a litre of oil may be used every 1,000 miles depending on type of use.
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What's for you won't pass you by
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It's a few years since I owned a car that needed oil between changes. My present 306 HDi gets oil (semi-syn) and filter every 6K miles, and the level drops about 1mm at most during that time.
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My Alfa quite happily goes along not using an extra oil. I do have it changed every 6 months as advocated by HJ but this is the only oil I purchase.
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Acceptable oil consumption these days seems to vary widely, from nil to the quoted 1 litre per 1000 miles. That to me is an incredible rate of use, reminiscent of my first old banger which left a smoke screen behind it as it pulled away. How do cars now manage to burn so much oil without making clouds of smoke, or poisoning the catalytic converter?
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The quote was "up to.." and not one litre per 1,000 miles..:-)
VW engines, providing they are properly run-in from new and regularly serviced, will last for incredible mileages.
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Ok - but are you all content to have the same old oil circulating for thousands of miles and eventually resembling watery gravy laden with the debris of combustion products and metal particles long before it's replaced?
Also, topping up from time to time must be a lot cheaper than replacing the entire sump full of oil and the filter mid way between recommended services - even if this is good practice.
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Have any of us actually stated that we are "...content to have the same old oil circulating for thousands of miles and eventually resembling watery gravy laden with the debris of combustion products and metal particles long before it's replaced?"
It's a somewhat arrogant assumption in my case for a start - I have the oil and filter changed every 6,000 miles at maximum....
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Ah but it is not just the old oil in the sump that leaks or is consumed but some of the new you have just topped up with. So your top up, which is a smallish proportion of a sump full anyhow, is not doing very much to replenish the lubricant qualities of your oil.
Much better to replace the whole lot more frequently.
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Surely all engines must use *some* oil? What about the very thin coating left on the cylinder walls which is then burnt? If this weren't there, there would be metal / metal contact. Maybe this doesn't use enough to be noticeable?
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The infamous 3 VW's mentioned again!
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"I prefer an engine to use some oil and require several top ups between services"
In favour of degrading the environment?
Oil burning cars do nothing for air quality
madf
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You could equally say the same of the thread...:-))
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Maybe this doesn't use enough to be noticeable?
I would agree with that. My 93 Polo (103500miles) still doesn't consume measurable amounts of oil and it hasn't had the easiest of lives!
Nowadays, engine manufacturing quality, lubrication and 'carburetion' systems have evolved enough to allow negligible oil consumption without any detriment to engine life.
Good quality oil has the right mix of detergents (which minimise the damaging effects of combustion deposits) and additive packages which allow the lubrication qualities to remain good for longer. So as long as you have the right oil changed at the correct interval, regardless of the oil consumption, what harm can you do?
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Adding oil to replenish additives seems to be quite effective: see neptune.spacebears.com/cars/stories/oil-life.html especially the Mobil1 extended test (18000 miles) at the foot of the web-page.
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- Yes, but what is the "correct interval" to change the oil/filter and prolong an engine's life?
VW's service intervals amaze/scare me. I bought a brand new Polo 1.9SDI last year and ran it for 8 months & 24k miles on its original factory fill of oil! I only had to add 1 litre during this time, and the service indicator was still saying I'd got another 1000 miles to go before the first service was due!
Surely this ain't good for the engine? Burning oil or not, would you want to run this engine in 3-4 year's time?!
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I would have reservations about running it that far. But, VAG would have studied these service intervals indepth (or at least I hope so!) so they must have thaught that 25K was OK. But doesn't it take into consideration how the car is driven (number of cold starts etc)
Looking back, many people must have had the same feeling when 10000 mile changes became the norm, after years of changing the oil at 3-5k. In fact BL introduced 12K changes in the early 1980s when alost of cars could still only must 5k.
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Ok - but are you all content to have the same old oil circulating for thousands of miles and eventually resembling watery gravy laden with the debris of combustion products and metal particles long before it's replaced?
Hopefully the harmful sized debris will have been caught by the oil filter.
In my pampered, V6 Mondeo, I change my oil and filter every 6 months, regardless of mileage, fitting a Ford oil filter and Texaco Havoline Fully synthetic 5W/40 oil. i only actually do about 8,000 miles per annum so it gets changed every 4,000 miles and the oil is still fairly clean at that.
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When I bought my Passat 130 hdi in july the dealer said it won't need an oil change until the car tells you it needs one. No 1500 mile check up, no 12000 service just a lifelong service programme and according to my driving style it could be up to 30 months before I need a service and oil change. I've done 10K miles in 4 months and drive fast when possible but still average 49 mpg and the car doesn't seem to want any oil or a service. I've filled up the washer bottle 5 times however!
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>>I prefer an engine to use some oil and require several top ups between services. Then I know that at least some of the lubricant will be 'fresh'.
Daft question. what makes you think an oil burner replenishes oil during top up..it wont work that way.once you have topped up say a cup full.. small amount compared to amount of oil in the sump..and hardly likely to prevent serious probs..Man dont state a given oil change for the sake of it..assumming you stick to oil recommended.No reason to think they are wrong
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Steve
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All irrelevant on a VW as they always last to incredible mileages and the build quality is so utterly, utterly amazing.
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Everything's relative, I know, but oil is still cheap by any standards, which is one of the several reasons I change it every six months, come hell or high water. It seems to me to be a false economy to scrimp on it. Thus, Mobil 1 (from Kwik-Fit) costs me less than six pints of beer per month for two modern cars and Castrol Magnatec about two pints per month for the Capri. That's peanuts for the psychological comfort it gives me and the physical comfort it gives the cars.
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If a car uses NO oil, what's left in there at the end of the service interval is what was in there at the beginning. (OK so oil changes composition over time, but you get the idea.)
If a car burns SOME oil, I would suggest it's likely to burn the lighter fractions first, leaving more of the heavier fractions. This will mean that at the end of the interval you're not using what the manufacturer intended. Maybe it would even burn off the detergents etc - I don't know.
Also, I don't think topping up the oil won't remove the debris. The debris won't be burnt with the oil. The oil will get more concentrated with debris as more oil burns off. Top it up and you dilute the debris again.
Anyway I think the filter will catch most of the debris. The problem is the stuff (nasty gasses etc.) disolved in the oil. However I guess these _would_ be burnt off with the oil.
Personally I'd rather have a car that burns no oil. It's cheaper on oil top-ups.
By the way, hands up who's had a car built after, say, 1995, which has died of oil-change-related things - excessive smoking etc.
-Mark
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I've never had any car die from any engine problem, and that includes a range of vehicles going back to 1947. In my experience car engines last forever if given basic attention to tune and oil change. It is rust that kills cars in the end.
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Ah yes but in the years after 1947 it was common to rebuild engines. Many a memory of father, uncles, grandparents etc having the engine out of the various bangers that were being run.
Things like rebores, oversize rings, crankshafts out for regrinds, new shells, camshafts, many many de-cokes, etc etc.
Any of that happen these days?
Much more was done in those days to give tired old lumps a new lease of life.
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I'm not disagreeing, I just think the year 1995 is a bit recent. I think the trend for engines to last pretty well indefinitely without major attention began quite some time before that.
My Triumph engine has run sweetly and with minimal oil consumption almost every day since 1964. The anciliaries are as original too - same starter motor, generator, water pump. I have had to replace the heater hoses and a small clip on the accelerator linkage.
The bodywork however is a bit shabby, and will probably need attention in a few years time.
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This thread shows that it is quite possible to build engines which 'use/burn' about a litre of oil every 50K miles (mine does). Therefore any loss must be down mostly to the control rings and bores (i.e.the running-in it has had) unless oil escapes from seals or gaskets.
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Uses no oil. What does that mean?
Does it mean, uses quite a lot of oil, actually. But there's a bit of a leak on the HG. Also the engine is inclined to flood & surplus petrol of course drains into the sump. And then the engine is used a lot on very short runs (out of the garage onto the drive) so water vapour condenses in the cylinders which also drains into the sump.
Therefore the 'pure' oil is in fact more like a water & petrol mixture with no lubricating properties whatsoever.
I've done about 6.5k since September, and the oil isn't as yellow as it was, and it's approaching the bottom of the marker again, so time to change it. (2 pints every ~3k miles, which is quite a bit but scarcely outrageous - & well within the rather ridiculous spec of the engine.) 5w40 (bit kinder on an old engine) fully synth (#15 for 5 litres) & a Halfords filter (#3.50) and 20 minutes. I'll spend more than that on a bottle of wine in a winebar. Quicker to DIY than to go as far as my nearest Kwik Fit, too.
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This may be of some interest.
My sister and I own scooters with 125cc capacity. They are both 4 strokes, and rev at 10,000 rpm. Despite this, I can ride from Brighton to Glasgow at 65mph (revving max) and they use NO oil at all.
Now, if a little engine revving this high uses no oil with 20,000 miles on the clock, then cars with 1600cc engines revving at 4000 rpm certainly shouldn't.
Of course, I never thrash the motor (even though they thrash themselves), and servicing is done on time. But in any case, it shows that if a tiny engine can use no oil, a car should not use any oil either.
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How much oil do they contain? How far does it have to travel around a 125cc engine?
Strikes me that in a tiny engine losses could well be less. And a smaller proportionate loss from a smaller amount might be negligible.
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IMO, mapmaker's analysis of the 'use' of oil really being the replacement of burnt oil by other impurities is absolutely spot on.
If the rate at which impurities get into your sump approaches the rate at which the contents of the sump are removed, perhaps being burnt off, then the dipstick level will appear not to change. This is not the same thing as burning no oil. AFAIK, an engine which burns *no* oil has not yet been built.
Practically, again, IMO, whether a car requires the oil level to be topped up between services or not doesn't change the appropriate service interval.
number_cruncher
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Number_ - I am prepared to accept that a few cars might do as you suggest, but surely if this process was common there would be some which appeared to create oil? The oil in a diesel which does almost exclusively long trips will degrade slowly, but I suggest that if the level stays constant it is not because of some strange mixture of processes which are mysteriously in balance.
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Andrew,
I think that if you have an engine which is worn to the extent where a large volume of products of combustion are adding to the sump volume, then you will also have an engine which tends to burn more oil. Perhaps it is possibly to acheive this mysterious balance?
number_cruncher
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Discuss...
Positive Spin: Uses no oil...
Negative Spin: Because for the last few years it has sat in the garage immobile, slowly rotting away.
I can see why they prefer to say the former.
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Its a load of rubbish.Piston rings need oil to seal..oil is trapped on bores..minute amounts are burnt at every stroke..though not enough to cause any damage to cat.or prevent engine from starting..No such thing as engine wont burn oil..they all do but in varing degrees....It is true that 10k is a long time for oil change..But if man/says its ok I see know reason to argue.?
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Steve
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