Is there some place on the net where I could possibly find something
like an equivalence table for these sort of item and manufacturers?
I'd particularly like to use a Super 4 type of plug from Bosch, but I
haven't found a proper match for the Motorcraft plug advised by Ford
for my 1994 Fiesta 1.3 - AGFS 22CM1, which is a plug without washer,
while all Bosch plugs I've seen so far have a washer, that doesn't let
the plug go into the combustion chamber properly.
I've been using Bosch Super 4 FR 78X, which as far as I understand is
what Bosch advises for my car, I've just checked the plugs today, and
compared them side by side with the Motorcraft recommended, and found
1) the plugs I've been using have too much carbon on them, which, the
way I see it, means they're either too cold, or they really aren't
going deep enough into the combustion chamber, or both, and
2) put side by side with the recomended Motorcraft plug, you can
easily see that there's a longer extension of the Motorcraft plug
going into the engine, than with the particular Bosch model I've
I tried cutting the washer off the Bosch worn spark plug, assemblying
it back in the engine, and apparently everything worked fine, but I
guess it would take a few hundred miles, at least, in order to get a
second valid check on the Bosch plugs . . .
As for the guides for the NGK plugs I've found on the net so far, I
don't find them satisfactory - they all point to a spark plug with
washer, which doesn't convince me.
Any suggestions, please?
Jose B. Ruivo