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Should I change my oil? - duncansand
I just topped up the oil in my new car (done less than 5000 miles). The first service isn't due until 12500 miles, but I notice the oil looks very black. It's a diesel (my first) - should I expect 'blacker' oil than with a petrol, or is it best to get an oil change done before the manufacturers recommendation?
Should I change my oil? - mss1tw
Both - the oil will be filthy within a couple of hundred miles (This worried me first time, too), but I service mine every 6000 miles rather than 12,000.
Should I change my oil? - MW
Run it in for the first 12,500 miles then have it serviced. Then change the oil and filter every 6,000 miles.
Should I change my oil? - Roger Jones
I think that oil in a diesel engine goes black almost instantly and it's nothing to worry about. HJ doesn't say anything about oil changes here

Otherwise, the advice above looks good.

I do believe I have seen advice somewhere against topping up frequently, based on the fact that it is not necessary as long as the level is between the min and max marks on the dipstick. And, of course, it should never be higher than the max mark.
Should I change my oil? - L'escargot
Stick with the manufacturer's recommendations. I'm sure they know best.
Should I change my oil? - Manatee
It must be a fair assumption that the manufacturer is competent in this but there are some trade--offs here. Longer service intervals appeal to customers, and thinner oils improve economy, but thin oil and changing every 20,000 miles is probably not the best way to mimimise wear even with synthetics. I am happy to change my oil and filter every 5,000 rather than 10,000 to reduce wear - I can't see any downside to this except the cost.

Reagrding the first oil change, HJ IIRC does not recommend early replacement of a factory fill of mineral oil with a synthetic, on the basis that this might inhibit proper running in. I am not knowledgable enough to question this, but I have just changed the oil in my Honda 2.2 i-ctdi at 5,000 miles anyway, on the basis that the oil spec is 0w30/0w40 synthetic and presumably that's what is in it from new (the dealer could not enlighten me but thought changing could only be good).
Should I change my oil? - Editor
yes, diesel oil goes black very fast. No need to worry. A lot of people who really care about their cars, & I'm including afficionadoes of the mad power modding fraternity here as well, change oil at about 5-6k even fully synth. Then again some don't! Which doesn't help you. I think if I ever had a car from new I'd have a really good look into what the 1st oil fill is composed of & judge accordingly. Think I'd have dropped the oil out by 5k though. FWIW my (new) bike had it's 1st oil change at 1000, standard service interval 4000. Honda.

Should I change my oil? - Lud
Diesels dirty their oil much quicker than petrol engines. HJ's advice, cited here already, is to leave the original oil in for at least 10,000 miles, why not 12,500, to 'promote some wear', and after that change oil and filters religiously every 5,000 or so.

'Promoting wear' doesn't seem intuitively the right thing to do to someone who wants to protect his car, but that is exactly what running in is. Properly run-in cars are sweeter, freer revving, more economical, more powerful and longer lasting. However you can't have everything and nothing lasts for ever.
Should I change my oil? - kithmo
And if you don't run them in, the bores glaze up and the oil control piston rings don't seal and you end up with an engine that uses as much (if not more) oil as a worn out one.
Should I change my oil? - MW
You have to run it in a bit, or it may be an oil burner for a long time, and it never will seem right. After that good high quality oil, every 6K.
Should I change my oil? - L'escargot
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."

Should I change my oil? - J Bonington Jagworth
"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.
Should I change my oil? - seeds
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.
Should I change my oil? - L'escargot
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.
Should I change my oil? - L'escargot
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!
Should I change my oil? - J Bonington Jagworth
"I'm not sure which gets pampered the most!"

The mower, by an order of magnitude, I would guess! (Based on likely running hours.)
Should I change my oil? - nortones2
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:
Should I change my oil? - quizman
>>>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.

Should I change my oil? - quizman
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


In fact have a look at this.
Should I change my oil? - L'escargot
Oil performs several functions ....

What else does it do, other than lubricate? (I'm talking about oil in a manual gearbox car, nothing fancy.)

Should I change my oil? - Collos25
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.
Should I change my oil? - madf
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.

Should I change my oil? - J Bonington Jagworth
"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!)
Should I change my oil? - seeds
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.
Should I change my oil? - quizman
Which error?

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