Any1 knows the impact of using IK20 instead of IK16 spark plugs

[Tanjm348]

Does any1 knows the impact of using higher temperature plugs instead of those as indicated by car manual. For eg.

 

Using: Denso irdium IK20 spark plugs

Manual: Denso irdium IK16 spark plugs

[Falc]

That's too cold a rating for you. The guide IIRC is for every increase in 30hp-40hp from stock, you should go one step colder. Now you are contemplating 4 steps colder ... ?

[Tanjm348]

I know the IK20 is a colder plug, or rated higher. But what is the impact when used in-place of IK16.

 

Loss in power?, knocking? etc

[Falc]

If it is too cold, electrically conductive deposits may form on the insulator (fouling) causing a loss of spark energy or the actual shorting-out of the spark current. Idling is affected, and in the long run, misfires will happen and of course loss of power not to mention damage to engine.

 

But if you TC your ride, then no issue.

[Bern2]

Think in the long run you will end up with more deposits & fouling on your plug if your engine is stock. Happened to mine after the workshop changed my plugs but gave me the wrong set. When I removed at the next interval the plugs were fouled but still working.

[Carstyle]

A colder plug like IK20 might be good for continuous long distance travel, like driving to Malaysia, but not so good for short distance travel.

[Genie47]

One of the reasons why there is a heat rating is that the plugs need to be "self-cleaned" by incineration. The deposits get burned away with higher heat. Of course you can't have it too high because there will reduce plug life and performance. Higher heat rating plugs conduct heat more efficiently to the coolant system.

 

If your engine runs very hot due to high combustion temperatures be it due to forced induction or gaseous fuels, then you will have to take higher heat rating plugs.

[Cyberet]

IK16 to IK20 is 1 step

denso and ngk uses different numbering scales

[Falc]

That makes more sense.

But i thought there is a IK22, so every 2 increase is one cold step increase?

[Cyberet]

dunno le, but theres no IK18 wor..

confusing denso

[Falc]

Ya man.

I know of a few models using NGK as stock even the 7E range. But not sure which models use Denso as stock.

[Hattee]

According to Denso at http://www.densoiridium.com/faq.php , IK16 is hotter than IK20. Meaning to say heat accumulated at IK16 is less dissipated than at IK20.

 

The 2 temperature of concern to spark plugs are about 500 deg and 900 deg. Closer to the former, plug loses self-cleaning, misfire and easily pitted by combustion residue. Above the latter, detonation can happen.

 

I prefer IK16 to get around 750-800 deg for very good self-cleaning every cycle and minimum misfire. With IK20, probability of my misfire is alittle higher when 95% of my throttle is only between 1500-3000 and rarely need to reach 4000, hence, may have less heat for 100% self-cleaning and affirmative firing.

 

Also IK16's 1.1mm gap is alittle wider than IK20 1.0mm gap.

Edited November 7, 2006 by Hattee

[Cyberet]

i thought IK20 is also 1.1mm gap?

[Hkarwai]

Can anyone expert advise? Me driving corolla 2002 1.5 manual. shop seller said Ik 20 better than Ik16... have not fixed them in as want to confirm first b4 too late. Thanks

[Cyberet]

what did your manual state? 16 only? or 16/20?

for city driving, and short trips in singapore, 16 would be better.

[Genie47]

Aiyah gap can adjust if you don't like the stock gap.

 

However the 1.1mm gap is used because the ignition coil drivers are very powerful these days. Compare this to the sotong head dizzy drivers found in most of the COE cars. Too big a gap = more heat.

[Cyberet]

i have been making my plugs gap abit small, 1mm ~ 1.05mm

idling smoother, better low end where i do most of my driving in sg

Edited November 8, 2006 by Cyberet

[Hattee]

Yes IK20 is gapped to 1.1mm (must have mistaken with another make).

 

IK16 and IK20 are close alternatives. Don't exactly know how Denso assigned them to different engines. Seems they are not always similarly selected for a specific engine in other sites.

 

Maybe will depend on your driving profile. If frequently exceed 50% of max rpm, IK20 might be a better bet. Also, a check on the plug cleanliness (every 10000km) should able to tell if it has been colder than required.