Spark Plugs on a 5VZ-FE

[Walky88 Member Find all posts View Profile Close Walky88]

Hey all

I'm about to change my plugs and was wondering what is the best option.

A - Use Standard NGK Plugs which are a BKR5EKB-11 and change every 40k or.....

B - Use Iridium NGK Plugs which the equivalent is BKR5EIX-11 and change every 100k

I know the standard plug is a dual ground electrode where as the iridium plug is a single gound electrode.

I can get standard plugs for $13 each or Iridium Plugs for $19 each

Thoughts????

[Walky88 Member Find all posts View Profile Close Walky88]

So just reading the NGK website i found that the Iridium IX Plugs are only designed for 60k

Therefor using iridium plugs would cost $228 for 120,000km usuage (2 sets) and using standard plugs would cost $234 for 120,000km (3 sets).

Seeing as though the price is basically the same and i'm only saving time in replacing plugs (which doesn't take long) Is it worth running Iridium plugs???

Does the 3.4L need twin ground electrode plugs???

[glen_ep Addicted PP Member Find all posts View Profile Close glen_ep]

So just reading the NGK website i found that the Iridium IX Plugs are only designed for 60k

Therefor using iridium plugs would cost $228 for 120,000km usuage (2 sets) and using standard plugs would cost $234 for 120,000km (3 sets).

Seeing as though the price is basically the same and i'm only saving time in replacing plugs (which doesn't take long) Is it worth running Iridium plugs???

Does the 3.4L need twin ground electrode plugs???

There is no direct requirement to have double plugs in the engine. Singles do no harm, it's all about service intervals.

The reason it was designed with doubles was due to the 3x coils / 6x spark plug arrangement which causes twice as many sparks as necessary, therefor a shorter spark life span. Back then spark plug technologies were not what they are today, so the simplest way to extend the service interval was to use 2 earths. Today you have the choice.

If the iridiums have an expected life of 60k in normal engines then we may assume that they only have a 30k life in a double spark engine such as ours. However, I have personally used a set of BKR5EIX-11 iridums in my vehicle (before the supercharger) for 67k without any issues. From memory I think I had a power increase after I eventually changed them but that could have be imagined.

Bottom line is go with either.

Now with the supercharger I use double earths but only because no one stocks iridiums of any brand which are 2 steps cooler - cooler being requirement when running a supercharger. So I'm using BKR7EKB-11.