I have been using iridium plugs with great success in my Alfa engines. Iridium has proven to be a superior, modern improvement in spark plugs. It is not just a marketing gimmick. If you sign onto using iridium plugs, I recommend opting for Denso not NGK. The Denso plug has a smaller electrode which has proven to produce better power. Based on a Denso iridium white paper, there is a trade off between power and a plug life based on electrode size. www.sparkplugs.com has been my source.
In the Alfa V6 2.0 turbo, the iridium plugs wore away at the ground electrode. The turbo environment is just difficult on plugs. Last change, I opted for an expensive Denso racing plug that has an iridium electrode, plus a platinum ground electrode. The jury is still out on getting my value for the 3X extra cost of the racing plug. On the turbo engine, Alfa recommends changing plugs every 20k Km (12k miles). There for a while, I had to change plugs each year due to mileage. For the turbo engine, 12k miles was not just a recommendation, it was required. Ken -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of George Graves Sent: Sunday, April 25, 2010 1:21 PM To: [email protected] Cc: <[email protected]> Subject: Re: [alfa] My GTV-6 has developed a "miss" What NGKs do you recommend? Thanks. George Graves '86 GTV-6 3.0 'S' -- to be removed from alfa, see http://www.digest.net/bin/digest-subs.cgi or email "unsubscribe alfa" to [email protected]
