I'm bored today so I did some car maintenance on a new to me Audi A3. These plugs are out of a 1.8T powered Audi A3 from 1998. They are original and the car has been around a couple of different continents and in some harsh elements. I replaced the plugs because I wanted to, not because the car was doing anything wrong! It starts and idles great, good acceleration and was averaging around 23 MPG city and 28 highway in freezing weather conditions lately. I think the original owner burned mostly 87 octane fuel with occasional 91. No fuel/motor oil additives of any kind. The color and wear pattern look like it's been running pretty optimally from what I compare to. What do you think? Naturally they don't make these same plugs anymore for whatever reason! Weren't selling enough replacement ones maybe??? ;-) I replaced them with NGK BKR6E. Hope they can make it to 10K miles but I'll inspect after 6K.