Bosch's iridium Spark plugs are usually good for about 160,000 kms (100,000 miles) + or about 7 or more years.

 

Hello @RedSector, this vastly differs from what both BMW and Peugeot offer in my country for the factory spark plugs. I thought the factory ones were the iridium ones, are they not?

Currently the 1.6 170 BMW iteration (N13B16) engine and the 1.6 Puretech 180 (EP6FDT) both have a 40k kilometers plug replacement recommendations. With the 225ps non-hybrids and the 270ps 308 gti engine on 20k recommendations.

I think they're mad but my authorized dealer tech rep said BMW started on every 100k then dropped it slowly down to 40k after many many issues and therefore is very adamant about this.

 

Hello @RedSector, this vastly differs from what both BMW and Peugeot offer in my country for the factory spark plugs. I thought the factory ones were the iridium ones, are they not?

Currently the 1.6 170 BMW iteration (N13B16) engine and the 1.6 Puretech 180 (EP6FDT) both have a 40k kilometers plug replacement recommendations. With the 225ps non-hybrids and the 270ps 308 gti engine on 20k recommendations.

I think they're mad but my authorized dealer tech rep said BMW started on every 100k then dropped it slowly down to 40k after many many issues and therefore is very adamant about this.

I was going through my maintenance of what I needed to have done within the next month and I realized that I had never replaced my spark plugs at 105k. I currently have 131k on the truck and it still runs great, no lack of power, no rough idle, no check engine light, and the car runs perfectly. So I’ve come to the question of do I even replace them, or at least do I have to worry about it now or later, and maybe check RockAuto for replacement options. I know a decent amount about engines but would I be risking anything other than damaging the cats if a plug dies and it misfires? Let me know of any more things that I should worry about, or if it’s not worth worrying about now. Thanks!

Hello. Is it okay to use a spark plug that’s different from what the manufacturer recommends? For example, my Toyota and Acura both recommend NGK or Denso iridium spark plugs. Would there be any significant issues or differences if I were to install Denso platinum or copper plugs instead? Thanks!

 

Generally speaking, Iridium plugs @ 0.4mm style ones have much shorter time span than Iridium plugs @ 0.7mm style. Not all iridium spark plugs are the long-life type. If your spark plug needs replacement, you will experience that through your engine’s performance. Just look for any odd behaviour and if you are experiencing some weird behaviour in your vehicle. That will tell you when you should change your spark plugs not a general guide, you pull them and inspect them or follow the recommendation that is by no way guarantee of what you will experience.

This might be helpful from Denso
Service Life | Basic Knowledge | SPARK PLUG | Automotive Service Parts and Accessories | DENSO Global Website

 

The spark plugs in the 1.2 are known to fail earlier than the original 40,000km/4yr interval here in Australia, and are now set to be replaced at 30,000km/4yr intervals.

Please note this is km, not miles. I'm unsure if UK Peugeot dealers have similar figures, but this is the service schedule from Peugeot Servicebox - the French obviously use km as well.