GTcarz - Automotive forums for cars & trucks.

shortspark wrote:
> Jim, I double checked the Virgin Oil analysis reports at BITOG site and
> the 5w20 and the new 5w30 are indeed both synthetic blends. I don't
> think this was always the case however and the 5w30 you had such bad
> results from may have been the older, straight dino stock - it all
> depends when you bought it. Here is a quote from BITOG and the source
> is probably Ford but I'm not sure about that:

mine was definitely "synthetic blend". i still have a bottle i'm going
to throw into recycling.

>
> "This new oil (5w20) has been designed to provide the durability,
> cleanliness, and fuel economy expected of a Motorcraft product. Tests
> show it outperforms our own SAE 5w30 Super Premium Motor Oil. This oil
> has been thoroughly evaluated by Ford. It has performed flawlessly in
> over 300 dynamometer durability tests and has undergone vehicle testing,
> reaching as high as 250,000 miles in some cases. This is an oil you can
> trust. This new oil truly "exceeds the need". Refer to Owners Manual
> to determine which vehicles should be serviced with 5w20. Refer to TSB
> 01-4-7 for a listing of older vehicles which should be serviced with
> this oil".

the "TSB" makes it sound like ford propaganda to me!

>
> Since then, it appears Motorcraft has introduced their 5w30 as a
> synthetic blend as well, however, a look at the Virgin Oil reports for
> both shows that they are a little different in their additive packs,
> most notably in factors such as zinc, iron and copper although moly
> content is nearly the same.

those are all fine solid state additives, but they do nothing for
thixotropy [the property that affects grade with temperature - otherwise
known as viscosity index improver] or seal conditioning. the thixotropy
thing is very important because either insufficient quantity or quality
can quickly break down leaving you with thin runny base that may not be
able to sustain the right hydro-dynamic film engines depend on. [if i
really wanted to be contrarian, i'd even ask why it's even worth
bothering with solid state lubes, moly, etc., if the hydrodynamic film
is being sufficiently sustained - but i'm not a tribologist.] and
simply measuring viscosity alone is not necessarily the answer because
it's usually measured at 100C whereas pistons & rings operate at higher
temps than that, and that soot/combustion product can increase viscosity
while decreasing lubricity. i think this was the situation i
experienced - and the reason the engine sounded like it was about to
fall apart - the oil film needs to be right because it keeps parts
"floating" on oil, not directly touching. regarding seal conditioning,
same thing, you need sufficient quantity & quality of the right organic
conditioners to do the job.

now, here's the rub regarding traditional oil analysis - it won't show
you /any/ info on these organic additives!!! the relevant compounds for
both those jobs are not metallics so they don't show on the spark
spectrometry or acid/base reading! oil analysis is an /excellent/ tool
for assessing wear product and therefore engine health, but from what i
can see, without the ability to detect or quantify organic contents,
it's next to useless as a measure of initial oil quality.

>
> Synthetic blends such as these and others from the Phillips stall
> (TropArtic 5w30 and Kendall) are hard to define, as you point out, since
> there is no exact measure as to how much dino and how much synthetic
> must be in the mix before it qualifies as a "blend". Mobil Clean 7500
> is rumored to contain a third synthetic but Mobil always keeps their
> formulas close to the vest.
>
> I agree too that "blend" is a marketing tool but they are suppose to
> provide longer oil change intervals than straight dino which usually
> shows wear at, and should not exceed, about 5000 miles in normal driving
> conditions. Full synthetics are said to be able to go 10,000 miles so
> somewhere in between seems to make sense for the "blends". They are
> usually priced "in between" dino and full synthetic as well.

when mobil 1 first came out, didn't they claim 30k between changes? to
back away from that as mobil have done, it means that either
1. their initial claims were bogus
2. they're now scared of law suits
3. they've changed formulation, or
4. like everyone else, the bean counters are interested in sales volume,
so forget the facts!

>
> If you go to the BIOTG site and click on the forums you will find many
> different forum links, including Virgin Oil Analysis and Used Oil
> Analysis as well as general lubrication and gasoline engine oil forums.
> Try doing a search of "Motorcraft 5w20" at any of these and there will
> be many threads listed where you can read reviews of analysis reports
> and general comments about the Motorcraft oil (there are even some in
> which it was used in Honda engines). You will find that, like any oil,
> some are good and some not so good but, along with Havoline straight
> dino 5w20, you will see that most of the oil geeks there consider it
> among the best.
>
> MARTY
>

thanks marty! i may try havoline next time. but for the moment, i'm
happy with castrol gtx. especially on the crude & unscientific basis of
keeping my engine quiet & leak free!