Spark plug choices?!

Thanks, makes sense - ideally just want the cheapest items to keep me running. Pic of engine as requested. Obviously says 16v dohc but how do I know if its VVT or not?

I would choose NGK. for all petrol cars. Allways. Been using them ever since my moped in '86 My daughter just got problems with her Golf straight out from the garage that did the service fitting new Bosch plugs. NGK plugs fixed the problems.
And Iridium plugs may cost more but they last 40-50000km (?)
The Suzuki M engines are high compression ratio motors so I would choose the recommended plugs.
Dunno if the heating and cracking problems with the M13 cylinder heads can relate to the plugs, only pure speculation..

Suzuki owners manual specs:

Nickel/Copper plugs; Denso K20PR-U11 or NGK BKR6E-11
Or
Iridium; NGK IFR6J-11

So the cheaper plugs can be OEM too.

 

The bog standard plugs are around 1/4 the price of Iridium and I tend to agree with Podge, for an engine like the Jimny Iridium isn't really required, so bog standard will be fine.

I only fitted these as that was what was in my Jimny I like replacing like for like and at 50k miles the plugs I took out looked fine, I like doing a job once and then forget about it for a few years.

I doubt you would notice the difference between bog standard and Iridium, especially for the first few thousand miles.

The advantage of the iridium is service intervals. Fit and forget for 36k miles as opposed to replace with cheaper every service

I fit the Iridium IFR6J11 in my 2 jimnys