2003 GT - Ruthenium Spark Plugs?

[Phoneman]

It's time to change the spark plugs in my 2003 Vibe GT and while sourcing OEM replacement plugs (Denso SK20R11) I noticed that NGK has a Ruthenium spark plug specified for use in the 2ZZ that claims longer life and better performance.

Has anyone tried these plugs, and if so, what were the results?

[joatmon]

I hadn't been paying enough attention to even know that ruthenium plugs were a thing. The internet stuff I found is inconclusive, claims of performance can be placebo effect, and its too soon to know about longevity.

All that being said, they seem to cost about the same as the iridium ones, so I vote for giving them a try and letting us know how it goes

[Phoneman]

Finally got around to changing out my spark plugs and I did use the NGK Ruthenium HX plugs (FR6AHX-S). With sales tax, four of them were ~$70 from Autozone which makes them the most expensive plugs I've ever purchased.

So far they seem much better than the Autolite XP plugs (3923) that I removed. The Autolites weren't pretty but there was no significant damage to them other than the spark gap looked larger than it should be but I didn't measure it.

After changing the plugs, I ran some errands and my first impressions are that the car starts quicker and easier plus the engine runs smoother and feels more linear in power delivery.

I will update as time passes and I get more experience with these plugs. I have a 5-600 mile trip coming up this next week so I should get more details including whether or not gas mileage increases since I already track that.



On a side note, one of the reasons for the delay in changing the plugs is because I've had three clutches explode (on a stock engine).

I had a local transmission shop replace the worn out OEM clutch. 14 months later, it exploded when all the clutch material came off the disk. To their credit the shop warrantied the fix.

Approximately three months later it did it again and the shop replaced it again under warranty, but one of their mechanics blamed me for the failure instead of blaming the substandard clutch they installed.

When it happened a third time two months later I was fed up with the expense of a rental car and the down time of not having my car so I had a friend replace the clutch with an Exedy Stage 1 clutch kit from MWR.

So far, the Exedy clutch has felt much better all-around than the unknown brand that kept exploding. If anyone is curious, I still have that last clutch, pressure plate, and throwout bearing and can check it for markings and/or provide photos.