NGK BP6ES Plug Advice

[Atazman]

Am doing a valve adjustment and removed the spark plugs to see how things look.  The spark plugs are NGK BP6ES with about 16,000 miles on them. 

The car runs well (no misfire), but new spark plugs will go in.  Recently when we had the rush on toilet paper and NGK non-resistor spark plugs;  I bought both BP5ES and the BP6ES.

Seeing the condition of my spark plugs do you see any benefit for installing  BP5ES plugs?

Comments are appreciated.

[wayne R]

Don,,My perspective is --no--- dont fit BP5ES,you probably know that they are hotter than BP6ES, opposite to other manufatures,
and looking at your plugs,1-2-4-6 are the perfect colour, ---3-5- are a little hot ,see how the metal  electrode on the ends of
those two, are  very white, thats what the   top of those two pistons will be like in colour.
Its always great to check  spark plugs ,they give you a whole lot of information, and condition of the engine,
so as you can see yours is great.
And do it after running at normal operating temp,and before removing, better to do after engine has cooled off,
not like me with my second car 57 years ago,a 1963 Jaguar 3.4 sedan in New Zealand,i removed spark plugs when hot ,and when
refitting, i stripped one, i just about had a heart attack, did not know there was a fix in Heli coil, repair.
Jaguars have alloy head.----learnt my lesson.

[Pawel66]

Sorry, one question: is the color of the insulator ok? Is it not indicating too lean? Just for my knowledge.

[wayne R]

Pawel, yes i think you are right,just a little.
The other  thing that happens a lot is the correct recommended heat range
from manufatures are really not all exactly the same, in all different makes and models of cars.
To do with design,length of electrode, clearance inside the plug,thickness of metal,etc,etc,.
Another make i have had a lot of  experiance with is Alfa Romeo ,in US that is fitted with  Spica fuel injection,
they are similiar in that if the spica is not adjusted correctly can be a real problem with the wrong spark plugs fitted,
from different brands on the market, i owned 5 of these ,when i lived in CA.
Infact Alfa releast a special manual for 1973-74  2000 engine for CA models only,that i still have,.
regards.

[Pawel66]

Thank you.

[Benz Dr.]

I wouldn't go any leaner. Almost too lean on some of them.

[Atazman]

I thank everyone for the comments.  Sounds like my biggest concern is borderline running the car too lean.  I will not change to the hotter BP5ES plugs.  I won't plan any enrichment changes unless someone says I am in danger.
 
Checked my spark plug wires ...... all fell between 0.98 K and 1.14 K ohms.  I think I'm "good to go" for a few miles.