Ask Sarah: Is my lube still good?


Lastly, you don’t want the dreaded black sludge!  Routine oil changes will keep most engines from developing black sludge.  But if you own a VW, Audi, Saab, Chrysler, or Toyota, I’m just going to say ALWAYS buy fresh oil because these engines are notorious for the gooey mess (that’s the technical term) known as black sludge.  When the additives break down, the oil becomes saturated with contaminant particles and cannot suspend contaminants to keep them from settling on engine parts; thus your engine becomes the La Brea tar pits.

If the oil is bordering the high end of old age, you may want to see if the oil is API rated to meet current industry standards, especially if you purchased the oil for an older engine and want to use it in a newer engine. 

 API certification
You should be able to locate the API certification somewhere on the bottle.  This SH rated oil on the left shouldn't be used on newer engines.  Current API certifications for unleaded engines include the SL and SM ratings such as the oil on the right.  CF is a current API rating for diesel engines.  You can use any newer motor oil (such as SM) in an engine that required an older (such as SH) API certified motor oil. 

And don’t write off Amsoil because you can’t find their API certification.  Amsoil does not apply for API certifications for all of their motor oils (some are certified) for two reasons.  The first is the obvious: cost.  It costs between $100-300k per certification of a single passenger car motor oil formulation as well as annual licensing fees and royalty fees on each gallon sold.  The second is API certified oils must conform to strict phosphorous limitations, which Amsoil doesn’t believe allow motor oils to achieve the reduced wear and longer oil and additive life.  Instead, Amsoil will claim it “meets or exceeds the (current) API rating.” 

[MotoIQ disclaimer: The following action was done by professionals in a controlled setting and should not be attempted by newbies.]  You can always try tasting it.  True gear heads know the difference between old and fresh with a simple lick!  Of course, motor oil might not be your favorite flavor of lube.  Kojima is partial to Redline Shockproof Heavy gear oil.  It's his meal replacement on race days!

Got a difficult tech question? Email Sarah at


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