For Rex:
I sure hope that you don't mean that you're using '70's vintage motor oil in a recently-made vehicle. Requirements of engines (and - correspondingly - the proprietary additive packages of PCMO's) have changed tremendously in the last 30 years.
(As an aside, I might also suggest that you do some comparisons of specs on Mobil 1 and HAVOLINE Synthetic. Data on both is freely available on their respective web sites. Bear in mind that DESIRABLE characteristics of a motor oil include a high viscosity index (VI), low volitility, a high flash point, a low pour point, a low cold-crank viscosity (CCS), and high oxidation stability. And - after you compare their specs, compare their prices.)
Oh, and - no - I'm not an employee of ChevronTexaco Corporation.
Best regards.
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Jim Hinds
Columbus, Indiana
[This message has been edited by indianrefining1931 (edited 09-25-2003).]