Confused so bear with me, I have searched and found that some places say that 8v/16v non turbo plugs are the same NGK ZKR7A-10s. However Shop 4 Parts list the 16v as being different (and slightly more money) and also the 500 16v is listed as being different. I have however pulled a plug out of mine and found the number above ^ but not sure if they are right. The dealer who did my 1st service put the wrong oil in so I wouldnt be surprised to find they are wrong. They look a bit old too, more so than they should after 18k miles to be honest but hey maybe they were never done. Which is the right NGK code? thanks.