Hi All
Just got this back from the man at BP/Castrol oils.
It's as we suspected but it nice to have some official clarification.
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Hi Clive
Apologies for the delay - some GL5 high EP oils contain active additives
that can over time effect yellow metals and cause premature wear, but
modern additives tend not to be so aggressive - however we would not
normally recommend a GL5 product for a GL4 application.
I would suggest Syntrax Universal 75W-90, or EP 80W-90 both covering the
lower EP GL4 rating
Kind regards
Andy Griffin
Automotive Lubricants - UK & Ireland
Lubricants Technical Advisor
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