Iridium Spark Plugs

I decided to go for NGK Iridium plugs, as it was quite easy to source therefore reduce the chances of being ripped off by sellers who tend to markup with high margin for very niche products. Well yes Iridium plugs is pretty niche but it is gaining popularity in Malaysia. There are 2 Japanese brands that are offering this kind of plugs.

The only difference with Standard plugs is that Iridium plugs uses Iridium material for its center electrode. Iridium material has higher electrical conductivity therefore creates stronger spark generation. Though the Iridium plugs have smaller electrode tip compare to its predecessor Platinum plugs, it has sufficient hardness to withstand the combustion and it is suppose to last longer than Standard plugs.

The NGK Iridium's tip diameter is 0.6mm whereas Denso Iridium's is with 0.4mm. There shouldn't be much difference in performance. However I reckon 0.6mm tip is more durable than 0.4mm, that was the reason why I decided on NGK. According to feedback in some site, the NGK Iridium can last up to 80,000km. Though the cost is about 4 times of standard plugs, I felt it worth the money as it should burn the fuel more efficiently and maintain at good performance level throughout the 80,000km life.

I installed BKR5IEX-11, the No 5 is the recommended heat range for Vios and 11 is the recommended 1.1mm spark gap. I am now monitoring the fuel efficiency. As my fuel consumption is averagely at 15km/l, I don't expect this plug to improve much on fuel efficiency in my daily driving, perhaps the significant savings can be experienced in long distance driving.

However I noticed drastic improvement is smoothness in acceleration. Of course it has to be, as my standard plug had ran for more than 55,000km when it was replaced. The drastic improvement in acceleration was kind of expected.