MAT wrote:
> "Don Enderton" <Enderton@nosuchaddress.duh> wrote in message
> news:sOI0i.5504$yM2.3404@bgtnsc04-news.ops.worldnet.att.net...
>> My local Honda dealer, where I get my oil changed, switched from Castrol
>> to Mobil oil. Also, the paperwork and windshield sticker no longer
>> indicate the grade or weight (should be API service SJ "energy conserving"
>> oil, SAE 5-30 viscosity, for my particular year and model).
>>
>> I had an impression from years ago that Castrol was considered a superior
>> brand. Is that still true, and if so, why?
>>
>
> If you follow an average oil change interval, any API spec oil is just fine.

not "any" oil. motorcraft api spec "semi-synthetic" makes the seals on
my 89 civic leak like sieves. subsequently running castrol or mobil
oil, i've had no leakage problems from the same seals whatsoever.

first line oil analysis is spark spectrometry. [quick and cheap.]
that's good for inorganic components like zinc, but useless for organic
component analysis. on spark analysis, motorcraft oil appears to have
an inorganic additive package just as good as other oils. but if it's
causing leakage, clearly it's missing organic components like seal
conditioners - and this would never show on spectrometry. guess that's
why it's cheap.

> All modern oils are essentially good and better than they used to be.
>
>