Johan,

"NORMAL-Grey-brown deposits,  lightly coated core nose. Plugs ideally
suited to engine,  and engine is in good condition.," is the only
reference to "brown" in the Champion Spark Plug brochure I have.

Regards,
Tom Hanlon
Palm Springs, CA
84 Westfalia

Johan Nyberg wrote:

> Hello all
>
> changed the plugs yesterday. The old ones (NGK BP6ET) are a nice
> brick-brown colour. What can this tell me about the state of the
> engine? My
> repair and maintainance manual only gives different hues of gray, from
>
> sooty black to white, but no browns.
>
>   ************************************************************
>     Johan Nyberg, Sweden N 59o E 17o 25"
>     '86 Caravelle C
>   ************************************************************