On Dec 6, 6:03*pm, "js.b1" wrote:
On Dec 6, 5:34*pm, "Doctor Drivel" wrote:

One automotive engineer, not mechanic, said the best thing is use the likes
of Mobil 1 oil and a high quality oil filter that grabs particals of smaller

Actually since about 2004 Mobil 1 is no longer a true fully synthetic.
Mobil lost a test case against Castrol re Magnatec which was claimed
to be fully synthetic when it was in fact a hydrocracked Group IV
mineral oil. The use of hydrocracking paraffin etc into engine oil
makes a boost to profit from utilisation of lower grade stocks.
As a result Mobil themselves moved to it, so basically synthetic can
mean "true" polyolefin etc or blend of cracked mineral oils.

There is a true synthetic still available - Miller, however I think it
is about £65-69 for 4L. There comes a point when you are better off
changing a cheaper oil more often due to water & fuel contamination
and additive depletion. For a lot of stop-start driving your enemy is
sludge, high end oils can tolerate this - but it can be better to just
use a slightly lower oil and change often. Some cars have chronic
problems with "mayonnaise" under the oil filler cap which grows with
moisture contamination (poorly designed PCV system), others have
problems with cam profile (think one VW) in which case you should use
any particular oil they specify re additive packaged created for that
OEM.

It was a few years ago, but I did get a good semi-synthetic from
Vavolene. It was certainly better than the later Comma semi-
synthetic. Currently using Halfords synthetic (bought in advance when
on offer) but not overly impressed with its cold viscocity grading.
Seems rather heavy on warm-up.


As for fine particles, you can use micro-fine bypass oil filters. In

The Italian made basic filters P******* (I forgot) are supposedly
good. I'm not so sure, perhaps it is the filter which is causing the
loss in performance through warm-up. Come to think of it, I've not
done a hot, full throttle acceleration test with this combination.

OOp's, it's a 5W40 and I wanted a 30 . How did that happen? That's
an advantage of using synthetic, it's acceptable to use a lower
viscocity which results in higher performance usually beyond the
manufacturer's economy and speed/acceleration tests. At least in
older motors which specified inferior oils.

reality unless you are doing 35,000 miles per year the body of most
cars is likely to suffer hidden corrosion in seams (rear wheel arch,
hidden behind the front wheel arch tray) from about year 10 onwards
and some much sooner. Many cars use bonded in wheel arches, there is
no spot weld around the top part of the arch, the polyurethane bond is
about 1cm higher up on the outer face; as soon as any corrosion takes
place the lips are forced open and moisture can both penetrate and run
around (classic wheel arch at the 9-o-clock & rear of rear sill
corrosion on many cars). By 12yrs you have a real infestation and only
know when it pops through from the inside-to-outside corrosion.

I must check for this. Vehicle's over 10 years and has repaired front
nearside three years ago, so ripe for rusting, I know manufacturers
repair standards were not adhered to.

So balance maintenance with bodywork checks. If you buy new, apply
dinitrol in the seams if you plan on keeping for the long term. Once
corrosion has started little will stop it because car steel is so thin
ironically at the most vulnerable places; typically 0.7mm in wheel
arch areas and 0.8mm in bodywork, 1.0-1.2-(1.5mm) in stronger areas &
frame rails. Corrosion thus perforates through first then runs along -
hence the classic term "tin worm".

Well worth checking the various car forums for the "known faults &
problem areas"; can save a fair amount re contingency, pre-emptive &
avoidance.