A place for more technical discussions. Please make sure you post in the correct section on the site, this way it keeps the site tidy AND ensures you get a more relevant answer.
Mine had these in when I got the car. They claim massively high mileage before they need to be replaced, also I understand they should not need re-gapping as often as normal plugs, so I suspect they will stay 'in tune' longer and should give better mpg.. But the are about 9 pounds each!!!!