Best oil weight

[tberk at mindspring.com (T Berk)]

"toFUNit@yahoo.com" wrote:
> 
> I notice the same change with the synth when I switch it on my 8v GTI.
> On the rocco could not notice it, since it never had anythig else then synth
> oil changed every 3000km.
> 

It had been 3000 MILES, but I aint convertin' to kilometers for ya. 
:]) It can go up to 5k miles these days with modern oils, synth having
an even greater range.

This is predicated by your duty cycle; if in a very dusty area or lots
of stop & go traffic or towing on a regular basis you need to shorten
the length between oil changes.

> BTW, a none-list mecanics told me that changing oil every 3000km isn't good? I
> wonder why? I know I could change it with more km since it's synth oil but
> nothing should arm the engine for changing it every 3000km?
> What is the good km to change synth oil...
> 

I can not come up with a reason why changing your oil too much is a
bad thing except it cost a lot more monney, or perhaps the addative
package, which is expected to be consumed to a dergee over time might
be too strong over an extended timeframe. (???)

> I think that if oil is black, this mean that it's less workful to protect the
> engine, so I change it before it is turning black.
> 

No, it means it has particles in suspension. It doesn't mean it can't
still do it's job. One thing to remeber (more a dyno oil thing) is
that the detergent properties of new oil menas that it'll get black
very soon after you put it in. 

> Also, when you had changed to synth, you should alway stay with it, or you
> could go back to normal oil (Not thinking about doing this, but just curious!)
> 
> 16v 87
> Joel


Joel,

You can switch back and forth, never heard, read, seen any proof that
motors 'set' to a particular type of oil. Early synth oil was
'improved' with seal conditioners to aliviate the leaking caused by a
switch to synth that stripped the old gunk out of the motor's
interiors, exposing old dry seals. 

I put Mobil 1 15w50 in my JH (Rabbit GTI at the time) and I found I
could stay in 5th on a hilly freeway (280) here in the SF Bay Area,
where as before I had to downshift to 4th to keep at cruising speed. 

I also noticed a reduction in high temp, but I can't remeber specifics
anymore. 

I leave it in about 5k miles, I don't get much freezing weather in
California and only a few days of 100 degree F at that so I like to
run thick stuff all year, with an easy take off on cold mornings.

TBerk
changing email adrress to tberk@sbcglobal.net