Date: Mon, 14 May 2012 21:08:04 -0700
Reply-To: Stuart MacMillan <stuartmacm@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Stuart MacMillan <stuartmacm@GMAIL.COM>
Subject: Re: Castrol Hypuron 15W-40 Synthetic Blend?
In-Reply-To: <4FB07444.4070609@turbovans.com>
Content-Type: text/plain; charset="us-ascii"
I agree. BTW, the study of lubrication is called tribology. Factoid of the
day.
The thing about multi viscosity oils is that it's chemical "viscosity
extenders" that give an effective viscosity range. The oil "behaves and
lubricates" like a 10w at low temps, and like a 50w at high temps.
Unfortunately, the physical viscosity (the thickness of the oil) is very
thin to give a 5w or 10w cold temp rating. That can be a problem in our low
pressure engines, particularly in warm weather. I ran 20w 50 Red Line
synthetic oil for years, but it was a bit thick in winter. I broke a cast
aluminum oil filter housing when it was about 20 degrees starting up one
morning, (new 2.1 engine) and I've heard of stock oil coolers blowing up too
in cold weather.
Maybe run a 10w 50 in winter and a 20w 50 in summer? The mandate to get
better gas mileage has led to thinner oils that are easier to pump around,
thus using less engine power, and that's not what we need in our old loose
engines.
Stuart
'85 Westy
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Scott Daniel - Turbovans
Sent: Sunday, May 13, 2012 7:56 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Castrol Hypuron 15W-40 Synthetic Blend?
hi..
oil can be studied 'forever' .
I would say though ..
that generally .. a wide viscosity ratio is 'less good' .
You will notice there are not many very wide viscosity range oils.
like 10W50 is seldom seen.
Of course , anything that anyone says about engine oils can be challenged or
debated by others ..almost always.
what I personally think..
on our usually very used engines ..the higher number is the more important
one.
In summer on most vanagons engines that should be 50 in my world.
I think the oil pressure on a hot engine is very important ..
and the '50' is what helps there.
I do not find or think, myself, that on old engines ...it has to have a low
lower number .
I am happy with 20W50 in used vanagon engines in summer..
and find that oil pressure is always somewhere between 6 and 60 ..
in other words..
60 at high rpm cold at say 2,500 rpm ..
and 6 at a hot idle.
on the other hand ..and I'm still 'thinking about this' ...
I know a VW parts store where the owner swears up and down that TDI engines
must have a 5W30 in them..or a 10W40 ..
and that using 15W40 causes the hydraulic lifter tops or cam lobes to fail.
I don't know if that's actually true.
All newer engines generally call for thinner oils ..partially for fuel
mileage reasons I suspect.
one oil I like is Joe Gibbs high zinc formulation 15W50 .
For old fashioned flat tappet engines ..
which all our VW engines are ...
they would be happier with oils with more zinc additives in the oil ..
very modern oils are formulated with less of that addtive to protect
catalytic converters.
about friction at start up ..
oil really sticks to metal surfaces.
if you ever try to drain off every drop of oil from something like an oil
pan..
oil will be coming off the inside surfaces for a long, long time. Days and
days.
So on engines with say 150K miles on them....I don't think the really need
a really thin oil unless it's extremely cold.
I am big on additives to help tired engines ..
such as Lucas Oil Stabilzer .
the BMW 10W60 ..
expensive I bet and I am not convinced it is really right for our old
fashioned engines.
one member says he as always run Mobil 1 15W50 I think...and has 200K miles
and still going strong ..
I respect and appreciate that. A good product I am sure.
something that made a big impression on me ..
an article, years ago, about how a new engine makes so much more friction
than an old used one..
and therefore it was imperative to always replace the radiator with a new
rebuilt engine.
what I glean from that is that old tired engines don't have a much friction
..
and there is less to worry about ....just that mainly the oil is thick
enough ..
that it's changed regularly ...
and my 3 rules for caring for any VW engine going back over 40 years..
1. keep it in perfect tune.
2. keep good clean oil in it.
3. drive it nice.
the real right way to determine oil performance and health of an engine is
by oil analysis.
even regular ones, like every say 25K miles.
then you need two identical vans ..
of the exact same age and miles..
one type of oil in one, another in the other ..and compare long term oil
analysis results.
I think how it's driven is the main factor.
I have one very good 1.9 waterboxer engine with a piston slap in it..
I am pretty sure the owner of that engine reved it hard , immediately, each
time he fired it up.
We want to start our engines as gently as possible of course..
that is their worst mode...starting and the first few seconds, followed by
the first few minutes .
And don't let them sit idling cold to 'warm up' - that is really rough on
engines.
Start gently, drive gently first few minutes ..under light load so it can
warm up.
You can read this in a 1958 Mercedes 220S owner's manual even.
scott
On 5/13/2012 6:22 PM, neil n wrote:
> Thanks people.
>
> Ironically, given the jokes some of us make about oil discussions, I
> know very little about engine oil. But it's something I need to learn
> more about now.
>
> Maybe an oil with a wider range of viscosity would be best. I don't know.
>
> Google is my friend!
>
>
> Neil.
>
> On Sun, May 13, 2012 at 5:00 PM, John Meeks<vanagon@gmail.com> wrote:
>
>> Interesting stuff. Sounds like 'soot' is kept in suspension better
>> than coventional oils designed for gas engines. The shear numbers
>> look good. Resistance to shear might make up for the 40 weight. Don't
>> know what other factors are in play in the gas vs diesel comparison.
>> Anyone?
>>
>> 15w50 Mobil1 is really hard to find this year for me. NLA? Some
>> 10w40 is still on the shelves which is what I ran last winter.
>> Looking around for alternatives.
>>
>> John Meeks
>> '91 Vanagon MV Phoenix
>> Northern Michigan
>>
>> Vanagon Rescue Squad
>> www.vanagonauts.
>>
>>
>> On Sun, May 13, 2012 at 3:49 PM, neil n<musomuso@gmail.com> wrote:
>>> Hi all.
>>>
>>> Searched "Hypuron" in archives. Didn't get any hits.
>>>
>>> I don't know if the TBN and Low Ash aspects help a gas engine, but
>>> looking at "Oxidation Control& Shear Stability" here:
>>>
>>> http://www.castrol.com/castrol/genericarticle.do?categoryId=82915547
>>> &contentId=7025207
>
>
