Mk5 gti plugs.

[mjmallia]

Every two years for me and I barely do 4k miles a year these days

[imprezzaworks]

New plugs fitted earlier :)

[ROH ECHT]

I find it difficult to understand how more resistance makes little to no difference.
When NGK makes statements like: "Lower resistance means more of the ignition coils energy is going towards bridging the gap of the spark plug....resistor type plugs actually resist some of the spark energy, non-resistor type plugs actually deliver a more powerful spark."

Anyway, I put in a call to NGK and left a message because I phoned 5 minutes after closing. When they return the call I will ask more on this and will report what 'they learn me.' I've spoken with one from NGK before, for about an hour one day, and so I have been saying what I say based on that conversation. It's what I do, having nothing else really to do, LOL 

[pudding]

It doesn't though, not in my car at least.  Don't take this the wrong way, but American car enthusiasts seem to be obsessed with spark plugs and gaps 

In Europe, we just take them out of the packet and throw them in!

If we're talking massive hybrid turbos running crazy rich mixtures, then fair enough, but these are just stock engines with stock parts.  No special plugs or gapping is required.

IFR7X8G lists as an OEM plug on NGKs site, and = 5K Ohms.
BK7REIX = 5k ohms.
PFR7S8EG also OEM and lists as = 1K ohms.

If the plug manufacturer lists different plugs and resistances for the same engine, it surely doesn't matter in the grand scheme of things? 

As I said previously, I suspect the difference is down to conductivity properties.  Platinum is less conductive than Iridium, so that's why they probably lowered the resistance.  It doesn't mean it makes a massive spark compared to a 5k ohm plug though.

[ROH ECHT]

Just got off the phone with NGK Performance Tech support.
They pretty much said all the same stuff as before.

They said the difference between 1k Ohm and 5k Ohm plugs is not likely to be noticed when paired with the OE stock C.O.P. coils. And; one plug will not likely out-benefit the other.
They said with their VW/Audi plugs...they just offer more heat ranges in their 5k Ohm plugs.

They also said do what a tuner suggests because they have their reasons, based on what they have or have not messed with in the tuning. Plus what hardware they require or is installed. Reducing the gap of the plug would likely need to take place regardless if it's a 1k or 5k plug, once tuned. But this is done if necessary, when or if you upgrade the C.O.P. coils to a higher voltage coil. Then is when you probably would want to always go with the 5k Ohm plugs. I think this is all we discussed.

Thank you Pudding for all of the input and feedback...nothing was ever taken the wrong way. This was all resulting from my own personal curiosity in the past and what I found out after making contact and having conversations with NGK. And yes...just put them (whichever they may be) in and we can deal with any problems later, should any arise. 

[pudding]

Yeah that pretty much mirrors my own findings, with the GTI at least.  I think it's just one of those engines that doesn't really care about spark plugs!

In my old VR6 Turbo project car, I used NGK R5671a-7 and that was the only time I could feel an improvement almost immediately. https://www.ngk.com/ngk-4091-r5671a-7-racing-plug

Probably can't use those in TFSIs as they have no resistor, so the coils might burn out, and/or cause too much ECU/DBW interference. They're good plugs though   

I have heard of people using NGK Racing plugs in TFSIs with no ill effects though, so I might give it a try.  I've got a spare ECU and throttle should the worst happen 

[ROH ECHT]

This morning I woke up remembering the most important portion of the NGK discussion which was the summary:

In conclusion they said (and confirmed by Pudding); there may not ever be any difference noticed between the 1k or 5k Ohm plugs when stock tuned.
But when it is tuned, and this depends on amount of increased boost and heat levels, they said this:
1) with "OE stock coils" you 'MAY' (I assumed meant; or may not) need to reduce the gap of a 5k Ohm plug before you would a 1k Ohm plug.
2) with upgraded "higher-voltage coils" you 'MAY' (I assumed meant; or may not) need to go one plug cooler with the 1k Ohm plug before you would a 5k Ohm plug.

Then I realized (I know, American spelling) NGK never mentioned something in all of the discussions, which slipped my mind, and I neglected to catch it until now. Which is; I was confusing flow/current being resisted, with voltage being resisted. But more resistance means more voltage and less current, and it is voltage needed to span the gap. Right?