Spark Plugs

[Fez887]

Just about to press buy on some new plugs for my 2.9 and thought I would ask if anyone had found a noticeable difference from fittings any of the more expensive plugs on the market? For example the standard I would consider to be NGK or Bosch (NGK currently fitted at last service), but there are IRIDIUM Platinum at a considerable premium. Anyone believe there is any value in these more expensive plugs?

[Fez887]

So that’s a no then? ....

[v8s4me]

Just get the cooking ones from Bosch or NGK. They'll be fine. The fancy iridium ones are for modern engines.

[phillpot]

v8s4me said:

Just get the cooking ones from Bosch or NGK. They'll be fine. The fancy iridium ones are for modern engines.....

... doing high mileage

Of course there is the " they cost a fortune i'm sure it's performing better" effect

[Fefeu52]

Modern engines are able to keep their plugs clean with an accurate control of their combustion (often deliberately too lean). In this conditions, iridium plugs can last for 70k miles. Our engine management are not accurate at all, even on catalyzed versions. The plugs will get dirty after a low mileage, expensive or cheap ones. For me, replacing the plug with a new £15 set every 15k miles is the way to keep an easy start and strong acceleration.