Best spark plugs for CLK280
 

I have a 2007 CLK 280 that had spark plugs changes at around 20,000, it's now at 44,000. The main dealer tells me they were changed early and should be changed now because of age, the car has not had plugs for 5 years.

The question I have is can anybody make a recommendation for the best plugs to ensure best performance. I'm not overly concerned about how long they last.

There appear to be so many types it's and brands, it's diffiult to make a decision on which to go with.

Thanks