I’m thinking of changing my plugs over Winter but am confused by the details in the owner’s handbook. They are currently Factory fit. I haven’t pulled them yet. Does anyone know the part numbers for both the Ford and NGK basic standard plugs? 4/4 Ford Sigma engine.
Thanks,
H
In my motorcycle spares business days over twenty years ago we sold a lot of NGK gold palladium tipped plugs. I thought I was honest in telling customers they offered little in the way of performance improvement compared to a perfectly set up ignition system with standard plugs. Their advantage though was the lower sparking voltage the finer tip allowed. Better starting therefore particularly from cold, and maybe better running when the chips were down. I never suggested they last longer than standard though. Indeed when removing a plug from my Moto Guzzi I could see the flame pattern orientation on the fine tip where it had melted slightly although the correct gap was maintained.
Iridium tips are the latest incarnation of this philosophy and I have one in my Velocette single which seems to provide very smooth idling. Too early to comment on longevity though.
With NGK coding the S suffix is replaced with V for gold palladium and IX for iridium equivalents.
I understood that the 3.7 V6 in later Roadster's has iridium tip plugs as standard but happy to be corrected.
