A3. Plugs and Coils Replacement

I had been planning to replace the plugs after having the 25,000-mile service done. Since the consensus is that the NGK BKR7EIX Iridium plug is the best choice, I ordered a set of 4 from OAKOS Automotive, an eBay vendor. They were $40 for a set of 4 + $2 shipping via USPS.

Note: There are variations of that plug model number with e.g. '-11' or other suffixes. They are not interchangeable. For the A3, you need the BKR7EIX exactly (they are correctly pre-gapped to 0.030").

A coil failed right at my 25K service, so as soon as I got the car back from the dealer I replaced the plugs. Since the coils are removed to reach the plugs, these instructions also cover coil replacement.