Date Added: Wednesday 24 July, 2013
Interesting how many reviewers bought these plugs along with other components (plug leads, air filter etc) then rated the plugs highly claiming superior performance. If one is changing two or more components in the system how is it possible to identify the one responsible for improved performance - if indeed it is real rather then perceived?
To be honest I bought these plugs and fitted them out of curiosity, changing no other parts, and the only thing I observed was higher fuel consumption. If there was any increase in performance it must have been extremely marginal because I didn't notice it at all. I removed the plugs after about 3,000 miles and found the white ceramic insulators to be discoloured where they meet the shell/body of the plug, as if they were twice the age - I hadn't expected to see that.
Now I've gone back to using Bosch R6 Super 4 spark plugs (the type I've been using for the last 5 years or so), which in my view are much superior to the NGK standard and long reach plugs.
Rating: [3 of 5 Stars!]