Dont understand the sludge because of low capapcity bit.
All cars can suffer from it for various reasons but the most popular is leaving the oil in too long before changing it.!
Personally on the mileage covered I'd agree with oldman and go for 15/40.
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Why recommend going for a 15w/40 instead of 10w/40? Question for clarification - I don't see any advantage but I may be missing something.
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As your Audi has hydraulic tappets, I'd avoid 15W40, as you might notice more rattle on start up.
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I would heed HJ's advice and change every 5000 or every six months, whichever arrives first. No harm in doing it more frequently either, especially given your short trips (that's "severe usage" in terms of engine health, in the same category as towing, habitual high revs, or constant use in hilly environments). It's a cheap way to keep your engine happy and prolong its active life.
Reflecting on all the megabytes of advice and opinion I've seen on oil, with your car at this stage in its life I would stick to 10W-40. As I understand it, 15W becomes relevant in hotter climates.
For more than you will ever want to know about oil, albeit clearly explained:
www.carbibles.com/engineoil_bible.html
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No need to read loads on this. As some have said above a branded 10-40 semi-syn is the oil for this situation. Locally there is AC-Delco in that grade for under a tenner and Vauxhall own brand (excellent oil) for just over the tenner. Great value for decent quality. 5000 or 6000 mile intervals ideal.
The less oil capacity in a car the harder it has to work and the smaller volume of it to carry the "dirt" in suspension. Hence it drops out and clings to the engine parts.
DW
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Absolutely. Increasing the 'cold' viscosity has no benefit and simply increases the wear when cold as the oil takes longer to circulate.
JS
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i wasnt going to bother but have seen too many posts now not to
the recommended oil for this engine is indeed 15w/40
an alternative is 10/40
the cars 14 years old
its done 130,000 miles
theres got to be wear in it
the 15/40 will fill the wear holes better
it may well have hydraulic tappets but it is not a zetec so is of no consequence for this equation
i gave my reasons for the age reason plus mileage and only one person agreed with me,whats the betting he has been out and under some automotive vehicle today just like me?
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Sorry oldman, but a 15/40 won't 'fill the holes better'. It will be the same as a 10/40 when it's hot, which is most of the time, and when it's cold it will be slower to circulate. Don't forget the all oils are much more viscous cold than hot, so a higher cold viscosity simply slows down the cold circulation. Oh, and I'm a qualified mechaical engineer, and have been one for 30+ years.
JS
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"Saw that high mileage stuff too, thats just cheaper oil in fancy packaging isnt it?"
Well err no.
I was sceptical BUT put some in son's Mark 3 Fiesta (1.1 efi) last but one oil change. It contains additives to swell oil seals and as a result oil consumption fell from around 300 miles /half litre to 500 miles/ per half litre. presume the oil seals are shot.
Quieter as well.
Used it again this change.. Can recommend for older engines . And not much more expensive around £16.50 per pack...
madf
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OP says this engine is quiet and only using 3/4pt of oil between changes. It could well be good for another 100,000mls.
Zetec or not a good 10/40 semi-syn will help the hyd lifters... it is just so much nicer than 15/40 mineral.
My own vehicles at 13yrs/150k, 13yrs 145K, 8yrs/100K, 20yrs/4400hrs all look to their dose of 10/40 s.syn for a long future... and they do not need their "wear holes" filling in!
DW
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Oh and 10 mile weekday runs are short trips so the faster cold circulation and better initial performance from the 10-40 s.syn is of huge benefit
DW
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All ois are a compromise
Thinner oils are promoted heavily for fuel economy not engine lifespan.
Oil specified by engine assembler is for a new engine with no wear. Ask an engine specialist or a oil specialist for a high mileage oil and he wont say the same as the engine assembler does.
15/40 imo (and other mechancics not librarians) is far bettetr for the engine in it present condition.
10/40 imo will alow more wear.
A good example of my opinion is demonstrated by the old fiesta engine. Originally from the factory it was specified as a 20/50 requiring engine. The same engine is now recommended to have 10/40 in it. The engine hasnt changed design its the mpg figures that have ! I wouldnt use 10/40 in 1 if you paid me too. I have refused to put it for customers before now because of the excessive wear it allows and not to mention noise etc.
But im only a mechanic!
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How exactly would a 10W40 allow more wear??? Its 'hot' viscosity figure is 40 as is the 15W40, but would not be so gloopy (or viscous if you prefer!) when starting the engine, thus quicker circulation etc (when most damage occurs).
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very difficult to give a consise technical answer too !
All multigrade oils use chemicals to stretch the differences, the bigger the difference the more chemical (and less oil) . 10/40 to 15/40 is obviously more stretched.
As an engine wears the gap between metal surfaces increases and needs more oil to fill it. If it doesnt it will allow wear. It is the thickness of the oil that helps fill theses gaps until the oil flow becomes quick enough to allow the thinner oil to work properly (hot multigrade oil).
Thinner at cold oils will drain away from bearing surfaces especially at top of engine such as camshaft and followers etc. This is where most wear is likely to be (noisy followers etc) and although a thinner oil will be assumed to get there quicker (very marginally and actual speed of oil is the same) the thicker oil flowing will result in less wear.
It will obviosuly cause more drag, hence the lower mpg and also make components like starter motors which have been made lighter duty too you may noticed, have to work harder.
When you have the physical chance to have similar engines run on different oils you will see the differences.
No body has recommended using thicker oil than specified by the manufacturer you may notice; just the best choice for the higher mileage.
Every vehicle operates different to another, town work, stop starts, motorways, garaged, left outside etc etc etc. No 1 oil can be the best for every engine, even the same engines. Ideally every engine should have the oil chosen for it depending on its use and driver style; but thats not easy to do. But ask an experienced mechanic or oil speicalist and he will listen to the needs of the engine not the marketing department of the new car sales departments.
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Disclaimer: I am not a mechanic and I am no oil expert.
On the Web, I've read a lot about oil. One consistent theme running through almost all of those sources is that 80% of damage is done when an engine is cold and the best thing you can do with a cold engine is lubricate it with an oil whose viscosity is relatively low when cold (think in terms of olive oil rather than grease). I may have it wrong, but I also thought that oil fiters -- at least in some cars -- have a contribution to make on cold start-up by releasing the oil retained in them to get quickly to the upper parts of the engine.
One query: given that the pour point of a 10W is lower than a 15W, at low temperatures how can the 15W reach a position at the same speed as a 10W?
But I'm in no position to be more assertive about this. I shall continue to use 0W-40 Mobil 1 in my high-mileage MB 300E twin turbo, specifically on the emphatic recommendation of the turbo manufacturers and fitters, and I offer the following as other sources of opinion:
members.aol.com/c1j1miller/oil.html
www.bobistheoilguy.com/
extension.usu.edu/files/agpubs/fm19.pdf
63.240.161.99/motoroil/
www.informationsavvy.com/motor-oil/
www.lnengineering.com/oil.html
www.carbibles.com/engineoil_bible.html
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Thin synthetic oils were designed for and are ideal for turbo engined cars !
Would still recommend slightlyu thicker oil in higher mileage engines
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Oil at ambient temperature takes time to flow around the engine. Its this aspect that causes most engine wear, some claim.
From A.E. Hass, a writer on fast cars, and contributor to Bob is the Oil Guy forum: 63.240.161.99/motoroil/101.html ?the greatest confusion is because of the way motor oils are labeled. It is an old system and is confusing to many people. I know the person is confused when they say that a 0W-30 oil is too thin for their engine because the old manual says to use 10W-30. This is wrong.
More confusion occurs because people think in terms of the oil thinning when it gets hot. They think this thinning with heat is the problem with motor oil. It would be more correct to think that oil thickens when it cools to room temperature and THIS is the problem. In fact this is the problem. It is said that 90 percent of engine wear occurs at startup. If we are interested in engine longevity then we should concentrate our attention at reducing engine wear at startup.
Oils are chosen by the manufacturer to give the right thickness at the normal operating temperature of the engine.?
There is much more in the link!
Re synthetics: they were first used for cars in about 1972, by a French oil company, well before the advent of turbos. As for viscosity, they are exactly the same at operating temperature as corresponding mineral oils, but can be significantly less viscous when cold.
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Couple of incorrect bits in there but pretty good guide.
However, no mention is made of oil spec for older higher mileage engines compared to newer ! It cannot be correct to assume that a new engine and an old engine will want the same oil !
Synthetic oil 10/40 is the same viscosity as mineral 10/40.
Synthetic oils are designed for turbo applications, regardless of the info you have found. You may wish to discuss with oil specialists for more info too.
For your information, I have been to several oil companies information seminars (via the trade) and do not expect to be able to discuss the complex subject of oil in detail on a page or 2 in here. But my advice stands.
The oil specified for the car mentioned, in this country, for this time of year is 15/40. Synthetic or semi synthetic is not mentioned but can be used. IMO 15/40 will offer more protection at start up in this case than 10/40 will.
But im only a mechanic, not a fitter !
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Roger
Most oil pumps are positive desplacement and flow same volume of oil be it thick or thin. With higher pressure more oil will bypass via relief valve. A 0W oil allows "Artic" starts and improves mpg during warm up.
Ali Haas tends to use Redline 5W20 oil which has basically same "viscosity as M1 OW40 at 150c so not all synthetics are created equal.
Yorkiebar
Interested in your views if you could expand on a complex subject.
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How many days have you got?
easier to respond to questions or give advice than try and lecture !
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Yorkiebar: you stated in an earlier post that synthetic oils were designed for turbos. Hogwash. They are often used in turbos but not exclusively. Suggest you do some more homework.
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Yorkiebar
Happy with lecture, although prefer discussion. As oil discussions are a little off topic, please feel free to discuss, if you have time, on the NORIA forum which is exclusively oil and free to join.
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Thank you for your informed knowledge and contribution.
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last comment was intended as a reply to nortones in case of doubt !
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Hogwash. Suggest you do some more homework.
Nortones, may I suggest you reply in a more polite manner if you disagree with someones opinion.
DD.
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DD: it was rather rude, so apologies to yorkiebar.
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Apology accepted, thank you !
Feel free to disagree, oil is such a complex subject even qualified experts disagree over certain statements.
Just disagree nicely !
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Have you changed the oil yet. What did you choose. I would have gone foe a 10/40 semi synth and 6K changes and filter. Regards Peter
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Yorkiebar
One key factor is that, at the time the Fiesta engine was designed (and it was a development of the 1959 105E Anglia engine) a mineral 20W/50 was a cutting edge oil. Since then oils have improved enormously, and viscosity isn't the only criterion. Buying a 20W/50 these days gets a very 'old' mineral oil, well below modern performance standards for friction reduction, wear prevention, sludging, service life etc. That '50' will quickly be a distant memory when used in a modern engine. What happened at Ford, was, I suspect, a recognition that the hot wear requirements were more than satisfied by a modern 40 oil with its improved performance and the lower hot viscosity gave economy benefits. The oil stays in grade longer, and the potentially higher flow rate due to the lower viscosity helps engine cooling. The lower 10W 'cold' viscosity gives benefits in cold starting and reduced cold start wear. Hence the revised oil specification. The engine may also have changed its design, in terms of the actual materials for key components such as piston rings, bearings, camshafts and followers. I'd have no qualms in using a modern semi-synthetic 10/40.
JS
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I don't want to get any more involved on this thread really, I think the op has more than enough opinions to make his choice of oil. indeed he may have done it already.
But, and its my last comment on this thread; please s tart this as a seperate thread if you want more involved discussions on the fiesta subject.
1 You have obviously not had much experience of using 10/40 of any type, in this type of engine, especially a higher mileage older fiesta as i chose as the example, if you believe your own answer !
2 You have chosen a new fiesta and say that i may have newer material internals ( I dont think so ). But I state that a fiesta 1100 of around 1980 was speicified as 20/50 but now is specified as 10/40. The enginein that car has not changed but the oil spec has. the mpg figures for it have also changed from figures published at the time.
3 I suspect that what happened at Ford was a realisation that the engines would last well out of their warranty on thinner oils so they could promote this higher mpg; regardless of the wear it will allow and inevitably shorten the life of such engine !
4 No way will i use a 10/40 in this type of engine. If a customer wants that they must take it elsewhere. I will specify 15/40 or 15/50 after a discussion on the type of use it gets. On a a very old worn engine then I would recommend 20/50 !
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i couldnt have written better myself yorkiebar your explanation is exactly right and your reasons for anybody that takes the time to read it are spot on
cylinder done on the old mk4 (you cant beat a likkle ratchet spanner :-) )
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Wasn't there an old saying that if an engine was using oil to "stick some Duckhams in it"?
Reason being that Duckhams oil was once rumoured to resemble treacle. ie, thicker oil meant there was less chance the engine would consume it.
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Yorkiebar
You should perhaps try this import from Oz
tinyurl.com/yyfq3a {Link shortened to a pdf file on the Castrol website as previously screwed up the page width of the site - DD}
Duckhams developed the 20W50 for the Mini although the polymers sheared in no time at all.
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There are some good 20/50's around, but shame the castrol 1 isnt.
Know a few applications where it would be useful.
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Yorkiebar
What do you recommend for a 20W50. Many years ago I used to use the valvoline race oils with higher ZDDP.
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Well thanks for all replies. I have decided to use the 10/40 part syth suggestion and use DD's tip for 6 monthly change intervals
Thanks
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and use DD's tip for 6 monthly change intervals
I think you'll find it was Roger Jones, via HJ's suggestion actually ;o)
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