Iridium spark plugs anyone use

[truckin 79]

Anyone have any feedback on iridium spark plugs? I have some deposits on my spark plugs that seem to be oil fouling. I have standard Delco plugs on there no and the center electrodes are starting to round a little. So I thought I would try some Autolite iridium plugs on the truck. I thought how could I go wrong with a coupon at Advance auto they came out to be about 50 plus these plugs have a lifetime warranty.

[Tom]

Lifetime warranty for being built badly, not for wear and tear and your engine running poorly.
Spark plugs, like oil, are not something to waste money on.

[fordguy40]

I run Densos in my Lightning. Wouldn't expect a dramatic difference in performance and I'm not sure how well they hold up in an engine with fueling or oil control problems. My understanding is that the iridium electrode is a bit fragile.

[LT7A]

My understanding is that those high-end spark plugs are meant to last a long time. That the exotic materials are for durability not added performance. I don't mind swapping out plugs, so I opt for the standard AC Delcos. My recommendation would be to invest the money in good spark plug wires, distributor cap with brass contacts, and a high quality coil if you haven't already.

[Nick_R_23]

Iridium plugs are pretty much the standards for what is mostly used today due to their longevity and resistance to fouling. They may be beneficial to you for the simple fact that it may allow you to go longer between plug changes on a worn engine. However, it sounds like your engine needs to be gone through.

[LT7A]

Well, last night I ran across some NGK info and they definitely call out the iridiums as quicker starting and acceleration. Sounds like you already have them, would you be willing to report back if you can tell a difference? And they are supposed to last four times as long as regular spark plugs. I will be interested to hear what you think.

[MJN]

While they're not iridium I am running ACDelco RapidFire platinum plugs in my '74 350 and haven't had an issue with them at all. The engine is rebuilt and doesn't have 5000 miles on it yet but no fouling or misfires at all with them.

[truckin 79]

I put AC Delco copper plugs in about a 1 1/2 ago and the center electrodes are starting to round when I checked them last week. I am trying the iridium for the longer life plus they are supposed to burn hotter to get rid of deposits. I have Bosch platinum on my 79 Trans Am and have had those for several years now, mainly because Trans am can be a pain to change plugs. I was fine with standard plugs on Truck since they are easy to change but thought iridium would be one less thing to worry about in truck. My truck does need some going through but I use it as my junkyard parts hauler mainly. It passed emissions here in CO and air fuel gauge is staying in that 13.5-14.7 range while driving and generally runs smooth. The only thing that the truck does is start a little hard after short trips 15 minutes or so. I have to crank it a few times and pump the gas to get it to start. On longer trips 30-1hr it starts right up with a twist of the key and no gas pedal. I am still waiting for plugs to come in the mail and then install and see how truck runs

[Tom]

Originally Posted by LT7A

My understanding is that those high-end spark plugs are meant to last a long time.

That sucks, my CBR's spec iridium from the factory and require changing every 16,000 miles

[truckin 79]

Well I put in the new plugs and took my first 2 hour trip on the highway to a swap meet. The truck ran great funny thing is with new plugs truck seemed to run a little richer. With old plugs air/fuel stayed about 13.5-14 and iridium plugs are running 13. At idle the new plugs are even hitting 12 so interested to see what happens when these get a little age on them. I thought new plugs helped with better starts but after walking around swap meet and trying to start truck I had some starting issue. So far new plugs act like old plugs .

[cadillac_al]

I have had such good results from the $2 Bosch Platinums that I don't dare to try anything else, especially if they are more expensive. I was sold when I tried them in my stubborn Camaro 20+ years ago.

[Factory Guy]

I run the factory plugs and electronic ignition in both of my old GM vehicles. No issues. I wouldn’t waste my money on iridium plugs unless your vehicle was built for them. Most automotive manufacturers who offer these iridium plugs advertise 120,000 miles for a set without changing them, however that being said they are in either all aluminum engine or at least an engine with aluminum heads. Our old cast iron heads and blocks probably operate at a different temps (in the head) than the newer engines.

For years i ran standard denso spark plugs in the truck, because i could get then easily and very inexpensively.

Today i now only run AC delcos. No fouling or miss firing. I haven’t pulled a spark-plug in the Chevelle in probably 7 or 8 years. Truck is probably the same.