Out of curiosity I pulled one of the spark plugs on the Mini this morning. They look like they should be changed to me. What do you guys think? The car has 159 K on it. I don't know the maintenance that has been performed or the last time the plugs have been changed. The plugs say NGK and BMW on them with R 5 in small letters.

 

I cannot tell from the blurry pics but look like a little carbon build up? If they have not been changed in a long time or you don't know when they were done, I would change them. I can see a little white of the insulator, but its hard to tell the milage just by looking at them.

The NGK R5 that state BMW are the factory plugs. part #
12120037608 BKR6EQUP Shared on the Cooper and Cooper S (without the JCW tuning kit)

https://www.ecstuning.com/Mini-2003-Cooper-R50-Base-Coupe-L4_1.6L_W10B16A/Engine/Ignition/

 

They are a cheap maintenance item. Change them anyway, and make a note of the mileage. Might be a good idea to change the ignition coil and wires at the same time. Can't do half-a$$ maintenance on a MINI.

 

You might want to review the several threads regarding changing spark plugs in this forum. They should be torqued to spec's.

 

My R53 developed a stumble, or misfire on full throttle, high RPM pulls. Went to change the plugs, wires and coil; did the plugs first, and that cured the problem.

I use single electrode NGK iridiums. The bad ones had burned and had over a .050 gap when I took them out. They weren't even that old.
Yours look a bit worn on the end of the electrodes (burned, rounded off) , but don't know if you will notice any change in performance if you replace them....

 

Yeah, sorry about the blurry pics. Must have held the phone too close. There was a little black on the end. Not sure how you would gap these.

 

yes chance them. good to keep up on that anyway