[Vwdiesel] Tradeoffs and Cheap Lube (long)

[Val Christian]

To clarify a few things...

> This is first hand experience.     In a lots of blow-by Rabbits ----lots =
> of fuel
> winds up downstairs.  Remember all the accounts of  "she is not using =
> oil" ???
> wrong ----it is being replaced by fuel.    I do believe Val Christian   =
> ----is telling
> it from personal experience. I also agree with him.  -----But read my =


	Generally the older 1.5 high blow-by Rabbits had the problem that 
	excessive oil splatter would collect in the intake manifold.
	It would get to a critical level, and then you had a mega 
	horsepower (the brakes WOULD NOT STOP IT) runaway car.

	There is a secondary issue in that usually a high miler would 
	also have incomplete atomization at the injectors, and drippy
	injectors, which would lead to crankcase oil dilution.  In many
	high mileage Rabbits I didn't see tons of this, although it 
	did exist.  

	The runaway engine was more of a oil-in-the-intake phenomenon.

	It is well documented that oil dilution is a common problem in 
	high time diesel engines.  


> Val Christian has had Rabbits from day one so when he tells us something =


	I think what Hagar is alluding to is my oil policy.  In general,
	I buy the best oil I think I can get for the early life of my 
	engines, and I tend to change more frequently than recommended.

	As my cars pass through 100Kmiles or 150Kmiles, I tend to use
	different oils.  There are diminishing returns on high end oil.

	Early in my ownership of diesels, it was easy to get reasonable
	oil at reasonable prices.  Probably around 84 or so, the CD and 
	SF ratings (I may have the exact timing and exact ratings wrong)
	became mutually exclusive. Consequently, cheap oil became more 
	difficult to get.  I simply started using SF or SG oil, in the
	same brands as I had used before.  I figured that things like 
	soot handling were not as critical when I changed oil at 2500 
	or 3000 mile intervals.  I had several Rabbits that I was the 
	original owner, and in general, they rusted out before the
	engines required anything more than a head rebuild and a 
	reringing. (never rebored a VW diesel) 

	Stated differently, over a 250K mile life (conservative), the
	"incorrect oil", changing oil at 2500 mile intervals, we're talking
	100 oil changes.  Using SF/SG/SH oil, I probably paid about 4 or 5
	bucks a change.  Let's say $500.  To upgrade the oil to a CD
	oil, we're talking an expenditure of about $1500.  $1000 difference.
	As near as I can tell, after comparing notes with many local 
	Rabbit and Mercedes owners, I get as good engine life as anyone 
	else.  Certainly good enough that the measurement error is 
	as great as any other obvious difference.

	In a high time engine, there are many benefits of frequent oil 
	changes.  Blowby contaminates the oil with soot, acids and other 
	by products.  Some of these contaminants are not effectively
	filtered, and are best controlled by swapping out the engine 
	oil.  Perhaps it's just a physchoogical thing, but I feel 
	better doing $5 oil changes, than $12 or $15 oil changes.
	
	In older cars, I tend to change the filter at 5K to 10Kmile
	intervals.  Depending upon the car, conditions, etc.

	Having said all that, in my 03 Jetta, I'm using Shell Rotella
	Synthetic, 5W-40, which is about $12.88 at Walmart.  I can 
	afford that, and the synthetic makes allot of sense with a 
	turbo, and the temperature cycles that the oil goes through.
	A case of VW filters is less than $6 each (wholesale) from the 
	dealer, so 03 Jetta oil changes are affordable.

	Hagar is right in that although there are scientific tools to 
	help us understand our oil, the actual practice and results
	of oil selection and maintenance are sometimes hard to 
	quantify, and appear as more of an art form.  

	Some group members have gone to conditional based oil changes,
	relying upon testing.  That's great.  Especially if you have
	a lab discount.  Some of us do a partial analysis using paper
	chromatography.  It might help to also get pH, particulate
	and soluable contaminants (like fuel).

	In the end, I don't really know what is right, but I do know 
	where I have an imperfectly formed comfort level.  And all of
	this writing has served to remind me that I have 15 gal of used
	oil to get recycled.

	Val