On 28/3/21 11:13 am, mike wrote:
On 27-03-2021 21:14 Scott Dorsey wrote:
Yes, that's why you test it.
Of course.
Under the logic of most people here they should replace the oil daily.
That's because it breaks down daily.
Oil in the engine is undergoing a continuous breakdown process.
Actually, if the truth be known, it is the additives in the oil which
are breaking down. So, when dealing with oil change intervals, two
factors need to be considered; additive depletion and oil contamination.
These are like the proverbial piece of string - there is no hard and
fast rule on when additives are sufficiently depleted or the oil
sufficiently contaminated to warrant an oil change. Ditto for the oil
filter.
When I was an apprentice, and later, a rule of thumb, backed by the
vehicle owner manuals, was an oil change every 5,000 km (3,000 mi) with
a filter change every 10,000 km (6,000 mi). This was the norm for the
average 6 cylinder vehicles (GM, Ford, Chrysler) of the day, 4 cylinder
vehicles had more frequent oil changes.
What has happened since then? Oils (and their additives) have improved
out of sight. Also, engine ventilation systems (PCV) have improved
vastly. This has extended the oil change intervals. My car, a Toyota,
has the oil *and* filter change interval *recommended* by the
manufacturer at 10,000 km (6,000 mi). So, the oil change interval has
been doubled but the oil filter change interval seems to have remained
static.
What seems to have been forgotten here is that the recommended oil
change interval will depend on the use made of the vehicle. If you do a
lot of short runs where the engine never warms up sufficiently, you will
experience greater wear factors and increased oil contamination
requiring shorter than recommended oil change interval. Will that impact
the filter change interval? Maybe. It really depends on the filter
capacity - the point at which the filter will block up and commence
bypass. A large filter of, say, 1 litre (1 quart) capacity might not
need to be changed more frequently. On the other hand, a small filter
with half or a quarter of the capacity might need to have a more
frequent change interval.
My Toyota, at 5 years of age and with over 100,000 km clocked up, has
servicing at factory recommended intervals. My wife's car, on the other
hand, has only done 40,000 km in the same time interval. It gets its
servicing, including oil and filter changes, done by *time*. In other
words, it gets an oil change and filter every 6 months *regardless* of
what's on the odometer.
The filter too.
Every day you replace the oil & filter and they won't break down too much.
But that's not the way the world works.
Instead you follow whatever specs your manufacturer recommends you follow.
That's why specifications matter. That's why the specs that matter are
usually printed on the oil container.
Manufacturer's specs are a *guide* only. Servicing intervals are
dictated by many variables - there is no hard and fast service interval.
It's not a matter of price or convenience which most others claimed it was.
It's a matter of knowledge and understanding of meaningful specifications.
Alls these other people know are dollar bills.
They make all their decisions based only on money.
That's fine.
It works for them.
But I like to make my decisions based on an understanding of the product.
And specs are part of that understanding of the product (for synthetic
oil).
For most laypeople, the specs on, say, the oil, are totally meaningless.
I don't get anal about oil specs. If the oil I buy meets the *minimum*
spec recommended by the car manufacturer, then that's what I go with. No
point in going with a more expensive or more highly speced oil if your
engine cannot benefit from the increased capability.
I am wide open about not knowing how to compare two different synthetics.
At least not yet.
I don't see anyone else here who knows anything about synthetic oil though.
Everything almost everyone else said they pulled out of their own assholes.
Especially the ones who claimed it was all about money and not about specs.
They can't understand what the product is as they only understand money.
Everyone understands money (even me) so it's easy (for them) to decide.
But I like to make my decisions based on meaningfully relevent
specifications which I openly admit I don't know what they are just yet.
I make my decisions based on the car manufacturer's requirements. I
figure they would have a clue about what works in engines they manufacture.
But neither does anyone else (at least not those who have responded).
So I guess I'm on my own.
It's been forty years since I took tribo class,
but at the time there was a standard measurement with a rotating drum
inside
a stationary drum that creates high shear on the test sample.Â* You
measure
viscosity regularly and plot it against time.
Isn't all that supposed to be encompassed meaningfully within the oil spec?
Why do you get so anal about oil specs? Pick an oil that matches your
vehicle manufacturer's minimum spec and you're good to go.
Clean linear paraffin oils did well on the test, oils with a lot of
crosslinking or rings did poorly.
You'd think a "synthetic oil" base would be pure linear paraffin
chains with a
very narrow range of molecular weights and you might be right or you
might
be terribly wrong, depending.Â* Also, of course, the VI breaks down,
not just
the base oil.
I tried calling both Chevron & Warren Distribution but I'll have to wait
till Monday to get their technical people on the line.
Sometimes they tell us a lot and sometimes they just spit out the
advertising so it's a crap shoot whether or not that call will bear fruit.
I think the best test so far of the Kirkland synthetic oil was this one.
https://www.youtube.com/watch?v=l9il_piyuT8
And I think the best single description of the (euro) specs is this one.
https://addinol.de/en/products/lubri...pecifications/
If you have something better by all means please let me and all know.
--
Xeno
Nothing astonishes Noddy so much as common sense and plain dealing.
(with apologies to Ralph Waldo Emerson)