NGK list the platinum BKR7EQUP spark plug for my car that can be bought for £98 for a set of six.

The Iridium plug BKR7EIX which I thought was a better item than the platinum is also listed and are only £35 for six.

Que?

 

I'm confused by the NGK prices these days too - for my Golf the Platinum (PZFR5D-11) used to be cheaper than the Iridium ones. But in this case - (BKR7EQUP) maybe it's the four ground electrodes with platinum on each ? It's also possible they've made the production process cheaper for attaching the iridium in the Iridium IX series

TBH you don't want multiple ground electrodes anyway as they block the flame front progression after ignition.

 

Depends on the engine.

The N54 BMW lump has THREE electrodes on the plugs as stock.
Bosch with BMW part nos. (ZGR6STE2)
Anything else just doesn't work too well.