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Old 10-02-2011, 03:07 PM
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RANDY P RANDY P is offline
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Join Date: Oct 2008
Location: Paris, Madrid, NYC, Mesa
Posts: 159
Quote:
Originally Posted by 1991 300SE Owne View Post
Deanyel, I am in Northern CA, Sacramento area. I can't find my manual at the moment, and after I found the old bottles of 20W 50 in my trunk, I decided to do the post. I used the 20W 50 when I lived in Los Angeles. I'm not sure now that Kragen's advice of 5W 30 is the best? I do change my oil every 7,500 miles, probably earlier than that. I used to change it every 3,000 like I do with my Miata.

It's my understanding that by using the synthetic 'blend' I could go back to regular oil if I wanted to. That is why I was using the 'blend'.
the biggest issue is that the older oil formulations (when your car was new) had ZDDP- an anti wear additive.

They started eliminating that additive around the late 90's, reason is that it when burned it causes Catalytic converters to die. However, in some engines it has caused the camshafts to go flat.

using certain formulations (like Rotella diesel- what I use) has higher concentrations of ZDDP- the latest "standard" passenger car oils all are formulated basically without the stuff.

rjp
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