On Mon, 4 Jul 94 12:13:43 CDT S.Smith said:
>None of the above use any oil in the 5000 mile intervals - i even had the oil
>analysed once by a bud in the fleet business and 2.5K oil and 5K oil
>spec'd out identically.

out of idle curiosity, do you recall what the viscosity had changed to in
the 5000 miles? i had my 30w oil analyzed by some folks in atlanta, and it
consistently changed into a 46w oil in 3000 miles.  your experience makes me
wonder if maybe it changes in only, say, 1000 miles. that is, maybe it doesn't
make any difference between 3000 and 5000 if you drive the car a lot.

i've also had the 20w50 oil anyalyzed at 2500 mile intervals, and can't
decide what the hell they are telling me: it's a 50w oil in the analysis.
??? is that because it's warmer here in alabama?

the most compelling reason i've heard for changing the oil SOONER rather than
later was to get the contaminants (acids formed by combustion, dirt and crud,
all that stuff that makes the oil turn black) out of the engine. and this
was brought home by a couple who had a beetle convertible ... they bought it
for an 'investment' back in about 1978. and only drove it 3000 miles per
year, little short 3 mile trips to and from work. well ... they changed the
oil like the book said: every 7500 miles. :( and the engine rusted solid.
the acids and condensation and whatnot actually rusted the engine so bad
that the mechanics had to break the cylinders to get them off the engine
to rebuild it: the pistons/rings had rusted to the cylinders.

now, remember that's an extreme case ... :)

i am, however, a bit disgruntled that steve's cars don't use any oil in
5000 miles. ;)

joel
<just rambling again>