Review on NGK (6737) PZFR5Q-11 Laser Platinum Spark Plug: Long-lasting Performance in a Pack of 1 by Jason Man

I bought 5 spark plugs for my 2006 VW Rabbit 2.5 liter 5 cylinder engine and one spark plug was faulty. and trembles a lot. I assumed the worst. After hours of figuring out what the problem could be, I finally pulled out all five new spark plugs I had installed that day, which removed the perfect seal provided by the new washers, and finally found the problem. A cork has 2 cracks in the porcelain. I then reinstalled 4 new good spark plugs and 1 old spark plug 1/16 turn and now my engine runs like new. This NGK defect cost me double the trouble and hours of headaches. I must also add that when my 9 new plugs arrived I inspected them and they looked like open boxes.