I've only had the MINI for a few thousand miles (two months and just over 30k miles). Since it has been hot and rainy here (south Texas); I've had to run the a/c and Mini has been running roughly. So...I got some Bosch 4+ plugs and changed them out. First, on the ease of change--it was half as easy as my old Land Rover (yep, four plugs, not eight). But, I was not prepared for the DEEEEEEEP cylinder/spark plug pit I had to work in. Glad I had a long extension for the socket! Second, my stock plugs were BMW-labeled NKG plugs with four electrodes. Glad I told the Autozone guy to get the 4+ plugs! Starting it up, idle seems to be smoother.

I know there has been lots of discussion on plugs--mostly the benefits of iridium plugs. I don't want to rehash all of those discussions. But, if anyone wants to know how the new plugs work, let me know.

 

Hey dougc,

I am gonna install these bosch 4+ soon. Any problems that any of us should know about? Are these gap-able, or fixed due to having the 4 prongs?

 

No problems since putting them in. They are gapped from the factory with four prongs. Still running strong with 33182 on the ODO. Can't tell if the new plugs affected mileage because most of my trips are around town. I did go on one long trip and averaged 32 mpg, though (2 over my best with the factory orignals). Hope this helps.

 

Is that the whole pn? +4, i'd be interested in trying, is this stock heat range?I'm going to need a little colder ,15% pulley.
Thanks,
Bill

 

No--the part number is 4417 for the Bosch 4+; BUT that is for a regular ol' 2003 cooper. I believe it is the same heat as the stock plug. According to the Bosch website the cooper s uses the same plug.

 

I have used the Bosch Plat 4's in several other vehicles and have seen great performance and increase in gas mileage as well. Nice to know that they will perform well in the Cooper too!

 

I highly recommend against the +4's. They work fine for the first few miles, and start giving problems within a few months. I have fixed many, many problems with lots of different cars by simply removing the +4's. Sure the NGK's are more expensive, but they only have to be replaced every 100,000 miles. Come on folks, you wouldn't run regular gas in your high performance engine, would you? You wouldn't put $10 brake pads on your MINI, would you? The proper plug is an NGK part #3199 (BRK6EQUP), less than $10 each at your local discount parts store.
On that note, does anyone know of 1 single vehicle that uses Bosch platinums from the factory? There are none, because they are cheap junk that Bosch as a reputable (and generous) company should be ashamed of, and their high dollar marketing has certainly paid off.
Sorry for the rant, but everyday I have to deal with problems caused by cheap parts on nice cars, and that goes for the quick lube service as well.
There are sources for quality parts and service other than the dealer, and yes, it does cost a little more than your typical discount parts, but isn't your MINI worth it?
Cheers,

--Dan

 

Bill,

I have 2 sets of the proper "JCW" spec plugs in stock, and it won't cost you $35 each (like the dealer). call me, I'll put a set aside for you.
--Dan

 

Dan,

Just grabbing info, i don't need plugs yet, i put the colder NGK plugs in after you installed s/c pulley.Thanks for your input on this as i trust your judgement on Mini's.I hope others take your advice as well.
Thanks Again,
Bill

 

Grassroots, it wasn't a matter of price. I have used these plugs in Chevys, Land Rovers and now my Mini without problem. So, I disagree. Are these the right plugs for a Cooper S, probably not. For my purposes ( a regular ol' mini), they are fine. Also, the electrode on the original plugs was nearly gone after 30k miles--I don't think the originals would have gone 100k.

However, I can't say that I have your experience.