<E28> 525e Spark Plugs

["Chris Northover" <chris.northover@xxxxxxxxxxx>]

Can anyone tell me what are the best spark plugs for this model?  My 1983
(European) model had NGK BP5EYs in it when I bought it recently.  These
plugs have a bifurcated electrode.  When I changed them I couldn't get the
BP5EYs, and instead fitted NGK BP6ESs, with an 0.8mm gap.  Both BP5EYs and
BP6ESs equate to N9Ys in the Champion book. The Haynes manual says to use
N9YCC or N9YCs, but these won't fit due to the fixed terminals.
It is doing two things :  it is idling quite roughly, and is pinking badly
when towing.  In fact, until I started using 98 octane fuel instead of 96,
it was almost impossible to tow with, as it pinked and overheated quite
badly...  I ***think*** this is due to plugs, as it got worse when I
changed. It also has 220 pound compressions, which seem a fraction high to
me!  Can anyone recommend plugs and gaps for a 525e?  Any other thoughts?

Chris Northover, Karori, Wellington, New Zealand
      chris.northover@domain.elided

       God so loved the world that He did NOT send a committee.

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