[morphius909]

I find this odd?

[CJ3Flyr]

My guess is the engine did all of it's emission certification on the 30k plugs and it carried through to production. Or for some reason the V6 is tough on plugs and long-life plugs couldn't make it 100k miles and the didn't want to sell long-life plugs with a non-standard change interval. That's just a wild guess and yes it is wierd to have to deal with plugs at 30K miles in this day & age.

[Neil]

It is strange but I have not had problems with mine getting changed every 45-50k instead of 30k. I have 92k so far on my engine and there has been no noticeable loss in mpg or engine power.

[Falls]

When I was looking at 4R's , and starting to get into them thats one thing I found odd was the plugs at 30k for the v6 , oh well I got the timing belt @ 90k with the v8.

[boston_kevin]

They say it has to do with emissions. The V6 has a 10.0:1 compression which is moderately high these days (most run in the 9.0 to 9.5 range) and has 4 oxygen sensors in line (2 per side) which may also contribute to changing these plugs sooner. The other odd thing you'll notice is that most of the V6's have Denso plugs on one side and NGKs on the other.

[Falls]

Originally posted by boston_kevin
The other odd thing you'll notice is that most of the V6's have Denso plugs on one side and NGKs on the other.

That also is so weird. I wonder what would happen if you just ran the same plugs on both sides ??

[boston_kevin]

Originally posted by Falls
That also is so weird. I wonder what would happen if you just ran the same plugs on both sides ??

I am running NGKs on both sides now and I have not noticed any difference.

[morphius909]

Are the plugs those special Iridium ones?