re: diesel lube oil

[tedcrum@xxxxxxxxxxxxxxxxxxxxx]

The industry-standard 15-40 diesel *lube* (Delo, Delvac, Penz.Longlife, etc.)
has an additive package designed to suspend a larger amount of soot than most
auto oils, is designed to resist varnish formation on hot piston skirts, and can
tolerate quite a bit of sulfur before getting too acidic.

These properties keep a diesel engine from getting dirty, but such oils have no
better than average ability to clean a dirty one.

One does hear stories of diesel *fuel* being added to an auto's crankcase as a
cleaner. I've used Riselone ocassionally over the years years to clean dirty
motors, with good results. (fast idle for 1/2 hour) It looks a lot like diesel.

When I've encountered really dirty engines, the root cause has very often been a
missing or damaged thermostat. I'll bet quite a few of the 3000-mile oil 
changers here have motors that run too cold, completely defeating their
extravagence.

I use a 15-40 diesel-type oil in both my VW and my 735i because the viscosity
grade is right and because it exceeds every spec ever set for a gas engine (it's
fully approved for gas service). I would surely do the same if I had a Nikasil
block (sulfur!) You don't need to change *that* stuff at 3k!

- -TC

- -- 
Ted Crum
tedcrum@domain.elided

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