Replacing Spark Plugs - OEM plugs and gapping?

[Salty Mope]

I swear I read a bunch of helpful info about plugs and gapping last month, but can't seem to pull that info up with a search now. It's probably buried in a tuning thread over on the S4 forum.

Anyway, my Q5 is at 42k miles. It's not idling rough or doing anything else to raise concern about the existing plugs, but I've read that plugs should be replaced anywhere from 25k to 60k, and I recently went APR stage 1 with plans for stage 2 this summer, so I figure now is a good time to get it done.

My question is mainly for those of you who have tuned S/Q5s. I'm sure I'd be ok going with OEM, but I thought I read somewhere that plugs with a colder rating are ideal if you have a tune. Is there any truth to that?

ECS has a full kit for $239 and I'll probably go with that unless somebody here pushes me in another direction.

https://www.ecstuning.com/b-genuine-...06e905115ekt7/

I'm also curious about gapping. Does it make a significant difference? I believe oem is .032 and APR recommends .028 but I could be wrong. I saw some of the S4 guys talking about .025 or .024. Hoping somebody can explain the potential pros and cons, and how much it really makes a difference for a tuned, but daily driving non tracked Q5.

Thanks for any help!

[SDV325]

It was my understanding that the coils do not need to be replaced for maintenance, only if they are showing signs of not performing/broken. Maybe someone else can confirm/deny, not 100%

I think OEM plugs are still recommended regardless of what stage you are. I know EPL recommends OEM plugs (NGK double platinum i think) gaped to 0.026" regardless of what tune/stage you are running. I changed my S4 plugs this past summer to NKG's gaped to 0.026, no issues at all ( i was EPL stage 1). Im going to do the same this summer on the SQ as well.

[bajan01]

I’m running an EPL DP W/M file (3.37 pr) with factory plugs gapped to 0.026”.

[stapan]

OP, funny you ask as I have the same exact miles, am getting plugs done tomorrow and have done a lot of research on it.

The short answer is get 6x NGK part number PFR8S8EG and gap them to 0.026".

[Salty Mope]

OP, funny you ask as I have the same exact miles, am getting plugs done tomorrow and have done a lot of research on it.

The short answer is get 6x NGK part number PFR8S8EG and gap them to 0.026".

Perfect, thanks stapan. Are you just replacing the plugs and not the coils? I assumed it was one of those situations where you might as well do them at the same time as the plugs since they're only an additional ~$150, but if it's not needed like SDV325 mentioned, then I'd be happy to keep the $150 and spend it on a dragy or something.


Edit: after researching a bit more, PFR8S8EG = part #101905611G, which is the same oem plug included in the kit I mentioned in the OP. So I guess I'm looking at either the kit including coils for $240 or just the plugs for $87.

[GoSQ5]

I recently swapped mine since I just got the stage 2 tune and it was recommended. I had 44k miles and went with NGK PFR8S8EG gapped down to .026



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[stapan]

Perfect, thanks stapan. Are you just replacing the plugs and not the coils? I assumed it was one of those situations where you might as well do them at the same time as the plugs since they're only an additional ~$150, but if it's not needed like SDV325 mentioned, then I'd be happy to keep the $150 and spend it on a dragy or something.


Edit: after researching a bit more, PFR8S8EG = part #101905611G, which is the same oem plug included in the kit I mentioned in the OP. So I guess I'm looking at either the kit including coils for $240 or just the plugs for $87.

Personally, I am not doing coils this time around because my Q was built less than 3 years ago but I plan to do them at my next plug change around 75k. Generally coils only need to be replaced if they are causing issues (there is no maintenance interval for them) but if its been 5+ years it may be worth changing them just for peace of mind while you have them out anyway.

[MSq5]

No need to waste money on coils unless you know they are bad. Highly unlikely for years. OEM NGK (part number is above) gapped at .026” is all you need.

[SDV325]

Oh and if you haven't bought them yet, buy from RockAuto.

Most places were asking $20CDN+ a plug for me (in Canada) but seeing $78USD is insane. I paid $78CDN shipped to my door from RockAuto, same OEM NGK plugs. My guess is they will be around $50USD for you guys in the states.

[Q5OnTheMove]

Those with NGK PFR7S8EG, did that com OEM with your car? My 2016 Q5 3.0 came with NGK BKR9EIX plugs gapped to .028. I have since gapped them to less then that based on VCDS logs showing clean logs.

[Salty Mope]

Oh and if you haven't bought them yet, buy from RockAuto.

Most places were asking $20CDN+ a plug for me (in Canada) but seeing $78USD is insane. I paid $78CDN shipped to my door from RockAuto, same OEM NGK plugs. My guess is they will be around $50USD for you guys in the states.

rockauto does seem to have the best price on these. They have $8.50/ea while everybody else has them close to $14/ea.

i have an appointment for tomorrow though so i couldn't wait to have them shipped out. will just have to eat the $30-40 difference. you did save me 150 that i was going to spend unnecessarily upgrading the coils though. thanks for that!

[MSq5]

Those with NGK PFR7S8EG, did that com OEM with your car? My 2016 Q5 3.0 came with NGK BKR9EIX plugs gapped to .028. I have since gapped them to less then that based on VCDS logs showing clean logs.

Interesting. My ‘17 3.0TFSI came with NGK PFR8S8EG! That is what I chose for replacement, but gapped to .026”.

[Q5OnTheMove]

Interesting. My ‘17 3.0TFSI came with NGK PFR8S8EG! That is what I chose for replacement, but gapped to .026”.

Wow, thats weird. Were a complete step in different direction (me being a step colder then you stock). I guess folks just have to play and see what works best