[ba] 10-40 or 20-50

audion audion at serversmiths.com
Thu Sep 20 13:48:18 EDT 2001

I've always run 20-50 in my Coupe but a couple of years ago when I had a
mechanic do some work he changed the oil and put in 10-40. I haven't
discussed it with him but generally trust his opinion.

Any concesnsus on the list about this.

BTW, I'm fully up to speed on all aspects of oils so I'm not looking for a
primer on that, just wondering if there are any ideas on why he might have
used the 10-40 other than perhaps he didn't have any 20-50 around ;-). I'm
looking for perhaps a specific tidbit concerning the 5 cylinder engine
"needing" 10-40 rather than a tip about how viscosities work ;-). Since it's
the original engine on a 19 year old car I'm leaning heavily to going back
to 20-50.

Every couple of years I wash the inside of the engine by doing a change and
putting in  some Castrol 20-50 and a cheap filter. I run it about 100 miles
or so and then drain it and change the filter to a high qaulity unit. I've
usually run Redline.

I need to change out the "wash" oil today or tomorrow and any tips are


He has all the virtues I dislike and none of the vices I admire.
-- Sir Winston Churchill

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