Iridium Vs Platinum Tipped

[gage]

i am going to replace the plugs in my 92 sc400. it came with ngk platinum tipped plugs from the factory that are supposed to last 60k or 72 months. what is the advantage of iridium plugs? i noticed that my 03 lx470 is equipped with iridium plugs that are supposed to last 120,000 miles.

[bean_8044]

Who would have thought... Spark Plugs .com Theres a dot com for everything i guess

[sightdev]

I am pretty sure your ’92 SC400 didn’t come with platinum plugs from the factory. Most likely the original plugs were Denso iridium but got changed. I did my change on ’96 SC400 about a month ago with 120k but they still looked good. With new plugs and cap/rotor, it does idle better with more throatier exhaust note. I was hoping I can increase the gas mileage with the change but it remained the same averaging 20mpg (which is good). I did a research and saw a comparison chart and it said the iridium electrode should last forever in normal circumstances but the tip is made out of copper, which will eventually wear out. I bought the + NGK iridium which the tip is made out of platinum. Major different between iridium and platinum is the failure point. One article said the Lexus decided to use the iridium for best performance. Price is marginally different so you should stick to the manufacture recommendation.

[SKperformance]

Iridium is the best for performance but platinum lasts longer.

Copper is one of the best conductors but wears quickly compared to them