Spark Plugs: Denso vs NGK
Hey guys just wanted to clear the air on some slight misinformation concerning spark plugs.
We get a lot of request for Denso ITV22's because people seem to think they are pre-gapped. I'm not sure where this rumor started (it has been around for as long as I can remember) but the ITV22's are not pre-gapped. They coincidentally come with a gap range of .030 to .032 which is good for the stock heat range plug, but when going with a colder plug you also typically need to reduce the gap. It is recommended to run a spark plug gap of .026 to .028 when you are operating at higher boost levels that require colder plugs.
The following is from Cobb's Website.
Quote:
Our data has shown that the factory spark plug temperature range (6) and gap (~.034”) are sufficient for stock boost levels and normal driving conditions. Although, operating the car with higher than stock boost levels or with the calibrations that are loaded on the AccessPORT, require that a spark plug gap of .026” - .028” (6.6 – 7.1mm) be used on a 1-step colder temperature plug. Denso currently offers this spark plug as part # ITV22 (please be sure to verify each plug is properly gaped before installing them). Our experience has shown that operating your turbocharged engine at higher than stock boost levels requires that your spark plugs be replaced at around 12,000-15,000 mile intervals.
NGK also offers a One Step Colder Plug comparable to the Denso ITV22. The NGK (LTR7IX-11) Iridium IX Spark Plug. The gap on these is typically between .035 and .037. Even though the gap is further from the ideal gap with the NGK's, it does not mean that it is harder to achieve the appropriate gap with these plugs.
From a performance stand point, with both sets of plugs gapped properly, you will not be able to tell a difference between the two. I hear stories from die hard believers on both sides about how terrible the other plug is but most of those guys have not had experience with both plugs. They just know a guy or have an uncle who says one thing or the other.
This brings us to availability. Denso ITV22's are currently on a galactic back order. We have had several hundred sets on order since December of 2012. Twice since then we got a shipment of four or five sets in and they sold out immediately. There is no ETA on when the next batch will come in nor how many it will include. However, we do have plenty of NGK Iridium IX's in stock and ready to ship.
So when trying to decide between the two, you don't need to worry so much about which one to get. Instead, just make sure that which ever one you get is properly gapped because they both require proper gapping.
Let me know if you have any questions and I'll be happy to help you out!
