Best Spark Plugs

[MichaelInChicago]

What would be the best spark plugs (brand and type) I should buy for my '15 650 GC?

Thanks

[Opie55]

I would use the OEM plugs, but you don't need to pay the extra to get ones stamped with BMW's name. They are probably NGK brand. But what I would do is do some searches for plugs for your car at reputable suppliers - like ECS or FCP Euro and see what they try to sell you. Once you find out the brand and model, you can probably get them at the local auto parts store. That's what I did recently for my X3.

[doggboy]

If your car is stock, the factory Bosch plugs are your best value. I you have a tune, there are 1 step colder and 2 step colder NGK plugs that are what most go with.

[Mnfamilyguy2020]

I too have a ‘15 650 GC. I confirmed the OEM plugs were BMW badged Bosch 8165. Changed them out three months ago. She has run flawlessly.

[NorthCountryGuy]

Just keep it simple and reliable.
Bosch.

[vaio23]

I had new bosh and after I got tune was getting misfires, upgraded to NGK iridium and running like a champ.

[TGrits10]

Can you post any of the part #s for the NGKs at different temperatures?

Follow up question, my plugs need replacing, currently stock, will do a stage 1 tune eventually, would it make sense to go with colder plugs or would they not play nice with a stock tune?

Thanks!

[MichaelInChicago]

I just changed the stock plugs to NGK Iridiums in my wife's X1 and the difference is night and day.

I will be changing them in my GC this week.

[thebmw]

Originally Posted by MichaelInChicago

I just changed the stock plugs to NGK Iridiums in my wife's X1 and the difference is night and day.

I will be changing them in my GC this week.

Can you describe what the difference is? Considering it's an X1, it's not a high-performance vehicle so I'm interested to see what kind of difference was noticeable. What about everyone's experience in the 6 series with upgraded plugs vs. OEM?

[Mnfamilyguy2020]

The material difference is about longevity. OEM is double platinum Bosch 8165. Have a tune? Adjust spark temp accordingly. Copper actually performs the best as it’s the most conductive material. Iridium lasts the longest of all the materials, can you feel a difference between double platinum and iridium in the same temp range??? I never have been able to through several high performance cars/engines.

[doggboy]

Originally Posted by MichaelInChicago

I just changed the stock plugs to NGK Iridiums in my wife's X1 and the difference is night and day.

I will be changing them in my GC this week.

The only way there will be a noticeable difference is if the old plugs were out of range ( gap increased or plug failing). l had a noticeable difference in my 650 as well, but that was because the factory plugs were at the end of life and the gaps were all over the place.

[MichaelInChicago]

Our X1 was running slightly rough, especially when accelerating, and felt slightly underpowered. You could even hear the roughness of the engine as well, if that makes any sense.

It could be that the plugs were just about at the end of their useful life but whatever the reason, the car runs immeasurably better now.

[doggboy]

Originally Posted by TGrits10

Can you post any of the part #s for the NGKs at different temperatures?

Follow up question, my plugs need replacing, currently stock, will do a stage 1 tune eventually, would it make sense to go with colder plugs or would they not play nice with a stock tune?

Thanks!

The NGK 95770 are 1 step colder but can be used with out a tune.
The NGK 97506 are 2 steps colder and should not be used without a tune.
The quick and dirty rule I have heard is one step colder per 100hp.

[pdubq]

I think bm3 recommends the ngk SILZKBR8D8S 97506, gapped down to 0.022-0.023” with < 30psi of boost.

Technically they’re recommending for n20/n55/s55/s63TU... I know I’m running it on n63TU, but on stage 1 OTS bm3 map they are doing fantastic so far!

[TGrits10]

Originally Posted by doggboy

The NGK 95770 are 1 step colder but can be used with out a tune.
The NGK 97506 are 2 steps colder and should not be used without a tune.
The quick and dirty rule I have heard is one step colder per 100hp.

OK, I looked up the 95770 and most/all sites only show it as a fit with the 3.0 I6 models, and only show 97506 for the 4.4 V8. NGK's site doesn't show the 95770 at all - does that mean it's been discontinued? A number of sites are out of stock or higher priced for 95770. Do folks regularly swap to 97506 on stock tune without issues?

[doggboy]

The 95770 fit the N63tu just fine, they are what I run. According to the NGK site that model was replaced by the 97968.

I would not run 2 step colder plugs on a stock motor.

[$howtime456]

NGK 97506. Gapped down to 19 if your running the car hard.

[TGrits10]

Alright then, just ordered up a set of 97968s. Any need to mess with the gap or is that a topic for later (i.e. Stage 1 tune)?

[MichaelInChicago]

Just checked with NGK directly and the 97506 is the OEM replacement spark plug they recommend for a stock 2015 650 GC.

[doggboy]

Originally Posted by TGrits10

Alright then, just ordered up a set of 97968s. Any need to mess with the gap or is that a topic for later (i.e. Stage 1 tune)?

You want to keep the gap as close to stock recommendations as possible. The smaller the gap the less energy. People gap down because higher boost has a tendency to "blow out" the spark if gapped too wide on our cars, which is why people gap it down to 0.018-0.022. For stage 1 I wouldn't gap it down that far. I am at 0.025 on BMS map 2 with E30 and I have no issues.

Just checked with NGK directly and the 97506 is the OEM replacement spark plug they recommend for a stock 2015 650 GC.

This is surprising as everything I have read, including recommendations from Burger, says that they are two steps colder than stock. I wonder if anyone will chime in that is running them on a stock motor, but I wouldn't do it.

[TGrits10]

Random FYI: the plugs do in fact require a 12-point socket, the stock images are not accurate, they show a 6-point shape for the plugs, they are 12-point IRL. So I've ordered me a socket and the plug change has been pushed back to this coming weekend. Meanwhile every stumble of the engine (gosh the cold start today was ugly) pokes at my nerves.

[TGrits10]

Installed the plugs yesterday, still need to do a closer inspection/analysis of the old plugs and get feedback from more varied driving conditions (so far I've taken it around the block post-install and drove to work this morning), but I've yet to feel a miss happen so that's...good? Anyway quick thoughts:

-Pretty easy, even the front cylinder on each side was no problem, hardest thing was getting the intake boxes back in just the right position to reconnect the rubber hoses.
-Total time including putting away tools after = ~2 hours.
-The bracing bars have a 15mm bolt on one end and a 16mm bolt on the other. WTF/whatever man.
-Took advice on the plug socket from FCP Euro not wanting to release and sprayed some WD-40 inside before I started. Worked beautifully. Used 6" + 3" extensions on most, 6" + 6" front cylinders.
-MFer those long threads put years on my life awkwardly leaning over the engine bay whipping the ratchet handle 90 degrees at a time.
-The new plugs all measured about a 0.028" gap out of the box, fwiw. I didn't mess with it.
-Old plugs coming out I measured a couple at 0.032-0.034" and then said screw it, analyze later. Didn't see anything obviously bad, will measure/examine the rest later.
-Patient is a 2015 n63tu @35k miles exhibiting stumbly cold starts, slight rough idle, and intermittent missing under load. Fingers crossed.