Bought these for my 2004 Mini Cooper s, after installing these spark plugs my engine ran smoother. Not sure if it is a testament to the spark plugs or the fact I just seafoamed the engine, either way there is a noticeable difference. The spark plugs fit as well as stock plugs, just had to set the gap at .35 and we were good to go.
These are good for 100k miles. Ran them in my A-series motor. These are in a Honda B16b vtec. These are 7's, which are the stock heat range plug. Drag racers run the 6's.