Date:         Tue, 7 Jun 2005 14:19:45 -0700
Reply-To:     Jeffrey Earl <jefferrata@YAHOO.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Jeffrey Earl <jefferrata@YAHOO.COM>
Subject:      Hydraulic Lifter Week*
Content-Type: text/plain; charset=iso-8859-1

(*Hydraulic Lifter Week is the world's premier
upper-valvetrain event, attracting participants and
spectators from far and wide. Held in the lovely
Calamari Coast region of southern Ohio, the event
hosts numerous workshops and competitions, so pack the
Loc-Tite and a stopwatch. Unlike that certain other
"Week" down in Daytona Beach, there are no wet T-shirt
contests, nor drunken brawls with the local
constabulary, so bring your family and your feeler
gauges.)


Actually, I seem to recall a study that analyzed the
engines of a fleet of NYC taxi cabs, perhaps the
harshest driving conditions a car is likely to
encounter. Starting with brand new engines, they
changed the oil of some cabs at 2000-mile intervals,
another group at 5000, and another at something like
10 or 12000 miles. When all the cabs had reached
100,000 miles they tore them down and inspected for
wear.

The final determination was that a cab could drive
something like 9000 miles between oil changes before
exhibiting any detectable signs of excess wear over
its 100k lifespan.

The Vanagon owner's manual suggests "at least twice a
year", assuming 1983 oil technology. By 1992, the
factory owner's manual of my Japanese econobox had
upped it to 7500 miles. With today's oil technology,
10,000 miles may very well be acceptable, even with
non-synthetic oils.

We all have to draw the line somewhere when
determining how long to drive between oil changes, and
I think "detectable signs of excess wear" is a fine
place to draw that line; anything else is simply
conjecture, speculation, and superstition. I once knew
a guy who deflated and re-inflated his tires every
month or so because he was convinced the air inside
went 'stale'. If the manual suggests 7500 between oil
changes and you want to play it safe, change every
3000. To play it safer, every 2000. To be extra-safe,
perhaps bi-weekly changes are in order.

Now, about those socks you wear for an ENTIRE DAY ...!


Jeffrey Earl
1983 diesel Westfalia "Vanasazi"
http://www.vanthology.com/



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