The larger the gap, the more voltage is needed to bridge the gap
- Opening gaps up to present a larger spark to the air/fuel mixture maximizes the burn efficiency
- The smaller the gap, the more likely the plug will fire
- The smaller the gap, the faster the plug will wear
- Plugs wear the fastest when there’s no spark
- Ideally, you want to run the widest gap you possibly can without misfiring
- “-11” at the end of NGK spark plug part numbers usually refers to a 1.1 mm (0.044”) pre-set gap
- Even if plugs come pre-gapped, they need to be double checked before being installed
Copper vs. Iridium (vs. Platinum)
FACTS:
- Conventional Nickel Alloy, a.k.a. “Copper” = inexpensive, best conductor, good performance
- Platinum = spark not as good as Copper, costs more than Copper
- Iridium = performance similar to Copper, longevity similar to Platinum, more resistant to fouling and oxidation than Copper, costs more than both
- The difference between “Iridium” and “Iridium IX” is the ground electrode material. “Iridium” (OEM) plugs have a Platinum tip on their ground electrode, so they cost more. “Iridium IX” (aftermarket) plugs lack the Platinum tip – they’re steel, so they cost less.
- Copper plugs require slightly more energy than Iridium plugs to fire
- Coil-on-plug systems (like on the WRX/STi) provide sufficient energy to easily fire Copper plugs, so Iridium plugs are essentially the same as Copper plugs as far as performance is concerned
OPINIONS:
- Copper plugs last 10-15k miles
- Platinum plugs last 30-60k miles
- Iridium plugs last 60k miles
- Copper plugs seem to be used by tuners as they tweak different parameters of the car and sometimes end up damaging plugs during the process since they’re cheap to replace. They’re also common in cars with high power levels since they’re likely to wear out plugs quicker than stock and slightly modded cars. They’re also for people who don’t mind changing their plugs (or who can afford to pay someone else to do it) every 10-15k miles. Changing plugs often and examining them can also be used to monitor an engine’s health.
- Iridium plugs seem to be the choice for owners who don’t want to worry about changing their own plugs (or paying someone else to change them) very often and still maintain a high level of performance
- Copper plugs are the only ones that should be used in cars with Nitrous
- Iridium plugs are better than Copper plugs in a forced induction engine because they require less spark energy to fire. As cylinder pressure increases (due to forced induction), more energy will be required make any plug fire, so Iridium plugs will be less likely to misfire than Copper plugs.
- Iridium plugs aren’t responsible for horsepower gains on dynos. They just happened to be firing correctly in cases when Copper/Platinum plugs were misfiring.
- Copper plugs are better for more aggressively tuned and boosted engines
- If you are pushing 22+ psi, consider Copper plugs because the electrode on an Iridium or Platinum plug is so small that it will continue to glow after the combustion event, setting the cylinder up for a pre-ignition issue on the next stroke.
- Copper spark plugs are your best bet
- The only real difference in plug material is service life (Iridium and Platinum plugs last longer than Copper plugs)
- If you are going to spend the money on Platinum plugs, you should opt for Iridium plugs instead because they perform better for about the same price
- Unless you're going to change your plugs yourself (read: free labor, buy Copper plugs because they offer the best performance), Iridium plugs are the best bang for your buck
Until recently, platinum was considered the best material to use on the top of an electrode because of its durability. However, Iridium is 6 times harder, 8 times stronger, and has a melting point 1200 degrees higher than platinum. Put that into a harsh environment such as an engine piston chamber, and you have a spark plug that can resist wear much better than platinum. Additionally, the DENSO Iridium Power alloy is so durable; it allowed our engineers to produce the world?s smallest center electrode (.4mm) which reduces the voltage requirements, concentrating its sparking power. Also, its smaller size, combined with the tapered U-Groove ground electrode, allows more room for the flame kernel to develop and produce a more efficient combustion.
Iridium use represents the most significant technological advance in automotive spark plug manufacturing, since platinum was introduced in the early eighties. As vehicle manufacturers produce increasingly complex and efficient automobiles, there is a greater need for long-life plugs that can tolerate leaner fuel mixtures and improved combustion processes. DENSO has responded to this need by developing its Iridium alloy, originally for OE applications. For example, many newer Lexus? and Toyota models carry an ultra long-life Iridium plug variation (.7mm with platinum tipped ground) that is capable of up to 120,000 miles of service. DENSO Iridium Power plugs, with their .4mm center electrode, have been developed for performance applications. Because gradual wear will ?round-off? firing points over time, the concentrated firing power and voltage requirement benefits will be reduced. For this reason, DENSO advises replacement after 30,000 (това се отнася за DENSO ,заради по тънкия електрод спрямо NGK )miles.
NGK's Iridium IX product range of spark plugs in the UK is aimed predominantly at the motorcycle market. There are now a few instances of cars officially imported into the UK (Mainly Renault vehicles) that now use Iridium IX spark plugs as standard equipment - proof that the motoring manufacturers have tried and tested and now trust the product. NGK Iridium IX plugs are much more freely available in the US and for a wider range of car applications.
Sparkplugs.co.uk keep most commonly requested Iridium IX parts in stock for immediate despatch and can obtain spark plugs to satisfy most other requirements on request.
The Iridium part of the spark plug is usually the centre electrode alone although some OEM Iridium plugs are available which also contain a chip of Iridium in the ground electrode. Service life of some OEM Iridium spark plugs can be as much as 120000 miles with very little degrading of performance in that lifespan. NGK Iridium IX types have a centre electrode tipped with Iridium alloy with a 0.6mm diameter. NGK believe this gives the optimum balance between performance and service life. Service life estimates are up to 60000 miles for cars and 20000 to 30000 for motorcycles although this is subject to application of course.
Като обобщение аз мога да кажа:
По ''корав'' идръжлив материла от които е изграден централния електрод (от там много по дългия живот на свеща)
По ''силна и концентрирана'' изкра заради самата конструкция (по тъкния централен електрод)
По ниско напрежение нужно за ''прехвърчане на изкрата м/у електродите спрямо стандатрните свещи (около 5KV)
По добро изгаряне на гориво-въздушната смес,по оптимална работа ан ДВГто
Икономия на гориво (заради по доброто горене,около 5%),както и лек пърформънс (има лабораторни иследвания които прават съпоставка спрямо никелови свещи,и прирастът на мощност е от 3-5% в полза на Iridiuma разбира се)
По евтините свещи (цена приравнена към живота на свещите - грубо казано -обикн свещи за 100К км подменяте 5 комплекта по 25лв = 125лв, Iridium IX за 100К км 1 комплект свещи на цена към 75лв !!!)
NGK LPG са си чист маркетингов трик от странан на NGK (те имат огромна продуктова гама...100000000 модела свещи,едвали не за всеки автомобил поне по 5 вариянта laugh.gif )
Инфо в нета има с купища,който го интересува да чете
