Seriously. What is up with spark plug prices? I am painfully familiar with the Porsche tax, but $47 per plug from the "discount" Porsche Parts dealers? That's for 1 plug best I can tell.

This is for 1970 914-6. Very stock 2.0L with CDI ignition and MARELLI distributor. I'm searching the factory parts catalog numbers and what they superseded to:

• 999-170-010-91
• 999-170-186-90

Thought maybe I could go direct to Bosch, but neither the Porsche part numbers or the product locator by model bring up any matches. I did come up with some indirect matches for a Bosch WR5DC at $5 each.

Based on other threads, and what's available, the NGK BR6ES also seems like the reasonable path for $5. Am I missing something?

Because no one buys spark plugs from Porsche. Spend the 5 bucks on NGK or Bosch. No one will every see them.

As Ben said. I use NGK's in my 2.2 six. I have NGK 7s, 6s and BR5es. I run a little rich so I now run the NGK 5s (hotter plug).

$5 spark plug

$45 Porsche tax

The nickname stealerships didn’t get invented without reason!

I've watched spark plug technology change over the last 4 decades.

The real ticket now-days is iridium plugs for street based vehicles.

In a modern COP installation they can last 150-200K and when customers ask "When should I tune it up" I respond NEVER!

I tell them they should wait till the MIL (malfunction indicator lamp) come on and a p030X code comes up and then change them all.

Many V6/V8 require removal of the upper intake plenum to access the plugs and a "spark plug replacement" can hit $600 on a bad one.

I have seen NGK take over the spark plug world. All Chevrolets use them, most Fords, 90% of the imports use them, etc

I prefer NGK over all other brands and in 40 years of active vehicle repair I've had 1 bad one out of the box.

Use the NGK at $5, they will not let you down.

I want to find an iridium version of that plug so I will never have to change them again....

Normally iridium versions are 2-4 time the cost of copper variants.

A quick check on Rock Auto for 75 914 2.0 is showing two Denso Iridiums available.
Part # 5306 and 4709 are available for 5.14/5.79 and part number 5306 has removable wire connections. This is most likely the one I'll use.
The copper NGK are 1.76 each.

If I cannot get NGK my second choice is Denso followed by Bosch.
Bosch nickels list at 96 cents!

This is most likely the plug the dealer is selling...

Just re-checked using 70 914-6 Bosch not available. Denso iridium 5307 is 5.79 and NGK copper is 1.76. I'd try the Denso first.

One issue with Iridium. They will survive a nuclear event, but they are brittle. Use EXTREME care when adjusting gap and ONLY bend the ground strap without touching the electrode. I DO NOT use a gap gauge for this. Feeler gauge with a light touch is how I go.

+1 with Iridium, my former 356sc would foul #3 often, an Iridium fixed that for good. I can't remember the price per plug, but well worth it. 15 years later she still fires great

$50./ plug no way for me

Do the Iridium's really work well in the older Porsche motors?

I have a 1985 2.8 DOHC straight six Mercedes M110 that doesn't like anything but old school non resistor copper plugs. Same for a 1983 Jaguar XJ6 I own. You try running any of the newer plugs and these motors will let you know they are not happy. Of course, finding non-resistor copper plugs isn't as easy as it used to be.