These days engines last well beyond my expectations and requirements so I think that trying to increase the life by changing the oil more often then the manufacturer's recommendations is like gilding refined gold or painting the lily.
"From Shakespeare's King John.
SALISBURY: Therefore, to be possess'd with double pomp,
To guard a title that was rich before,
To gild refined gold, to paint the lily,
To throw a perfume on the violet,
To smooth the ice, or add another hue
Unto the rainbow, or with taper-light
To seek the beauteous eye of heaven to garnish,
Is wasteful and ridiculous excess."
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L\'escargot.
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"trying to increase the life"
But we're not just talking about wear. Oil performs several functions and the manufacturers cannot know what duty cycle every car will endure. They extend intervals because they can, and because it looks good in the brochure. Unfortunately, the very people who take them at their word are also often the type who wouldn't know a dipstick from their elbow, and who might well allow the level to drop excessively.
Why not change it every 5 or 6k? It's cheap insurance.
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What is important with oil is the A or B rating.
A for petrol engines,B for deisels.
This is followed by a number,starting with one.
Currently we seem to have got to A3 and B3/4.
The number relates to the wear protection,A2 is twice as good as A1,A3 is twice as good as A2,and so on.
And you need fully synthetic,nothing else.
You can buy it cheaply in french supermarkets,shop around for the best deal,it was Super-U last time I stocked up,but it won't be now.You can also get 5 litres of Mobil 1 for twenty five quid in some of them,if you see it,buy it,its probably the best there is that you can easily find.
If you have a new deisel it will never properly run in unless you use the fairly ordinarily basic dealer bulk oil (Sometimes only A1)for the first 50000 miles or so.I have an Hdi engine here that has spent its life chipped out of its brains and driven by a mad Blonde,at 70000 miles its just stopped needing its oil topped up between services.
Fully synthetic degrades with heat and oxidation phenomenally slowly,for turbo engines,with oil cooled turbos this is a feature you need.
I even run my mowers on mobil 1,changed annually,and nobody would accuse me of being anything but a mean and miserly old git!
Cheap oil is like cheap shoes,you have to be very wealthy indeed before you can afford them.
Robin
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at 70000 miles its just stopped needing its oil topped up between services.
I seem to recall that the Hillman Imp handbook said that some oil consumption is necessary to ensure good lubrication. I assume the hypothesis was, for example, that oil needs to go down the valve guides to keep the valve stems lubricated and that this ends up being burnt. Also, as I recall, it said that 700 miles per pint (younger Backroomers can convert this into any newfangled metric units they like!) was normal. Whether this was an excuse for an inherently high oil consumption on that engine, I don't know.
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L\'escargot.
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I even run my mowers on mobil 1,changed annually ......
I put Castrol GTX Magnatec 5W-30, changed annually, in my mowers, and my dealer puts Total Quartz Future 9000 5W-30 fully synthetic (annually) in my car. I'm not sure which gets pampered the most!
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L\'escargot.
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"I'm not sure which gets pampered the most!"
The mower, by an order of magnitude, I would guess! (Based on likely running hours.)
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Although no expert I think this "The number relates to the wear protection, A2 is twice as good as A1,A3 is twice as good as A2,and so on." is a bit off the mark! The wear requirements in testing by ACEA are very similar, but the categories A1/B1 to A5/B5 and the new C categories are more related to visosity, oil change interval etc than quality per se. There is an explanation here: www.infineum.com/information/consumer.html
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>>>The number relates to the wear protection,A2 is twice as good as A1,A3 is twice as good as A2,and so on.
A1 is better than A2. Have a look at the oil thread on the top of the technical section, this tells you the correct information, and will stop people giving the wrong ideas.
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A1 Fuel economy petrol
A2 Standard performance level
A3 High performance and/or extended drain
A4 Reserved for future use in certain direct injection engines
A5 Combines A1 fuel economy with A3 performance
B1 Fuel economy diesel
B2 Standard performance level
B3 High performance and/or extended drain
B4 For direct injection car diesel engines
B5 Combines B1 fuel economy with B3/B4 performance
E1 Non-turbocharged light duty diesel engines
E2 Standard performance level
E3 High performance and extended drain
E4 Higher performance and longer extended drain
E5 High performance and long drain plus API performances
Cheers
Simon
In fact have a look at this.
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Oil performs several functions ....
What else does it do, other than lubricate? (I'm talking about oil in a manual gearbox car, nothing fancy.)
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L\'escargot.
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THe oil does not lubricate its the polymers suspended in it that do that ,it also has a detergent for cleaning and a sealing additive there may be more bits to it I am sure some chemist will give us the definitive answer.I remember going to a demonstration by one of the major oil companies where this chemist had suspended the additives in a variety of liquids milk being one I think the others were nut oil,water,washing up liquid and some more.They all worked reasonable well he concluded by saying that oil was an easy, cheap and accesible substance to suspend the additives but almost any liquid could be used at a pinch.
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I run my mowers on whatever engine oil (Usualy Comma 10-40 semi synthetic) comes to hand. The last cylinder Qualcast failed due to general wear of everything (including broken handles etc) after 20 years of mowing 0.5 acres of grass. The engine had a decoke and was starting to burn oil a little.
madf
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"What else does it do?"
Cools and cleans, although the latter requires an unclogged filter, otherwise the oil bypasses it (on the grounds that even unfiltered oil is better than none). Since these work like a hoover bag and are rendered less efficient by the debris they trap, I would worry that they might not cope with extended intervala. Modern ones don't seem to be any bigger...
(The old Simca 1100 had a centrifugal filter, thus being a Dyson by comparison!)
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I'm glad to see that quizman corrected his own error!
Ford took to using A/B1 in its engines because it gave a marginal improvement in economy.
Ihave some 5w30 B3/4 here,so it can't be related to viscosity,or at least not directly.
Viscosity itself is not a quality issue,for an engine made to close tolerances a lower vicosity may be better.Similarly aluminium engines,which expand more than pigiron ones,may need a higher vicosity.
I've always wondered why the aftermarket boys don't offer big low resistance filters.
Robin
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