Here's some more info...
Porsche 997 Turbo ECU Tuning and Spark Plug life

I have to say that my plugs looked similar. My car was pre-owned and turns out that shortly after I got her she started to sputter (misfire in the high RPM range on throttle).

I decided to change out the coils (replaced the OEM 996 that came with the '07 Turbo with 997 ones) and plugs at the same time and went with OEM. After substantial amounts of research, none of the manufacturers could claim that their spark plugs would out last or even out perform the OEM ones. A lot of opinions but no hard facts - none that I could source, or get sent to me. Additionally there's a lot of misinformation out there as to best choices, so I went with the safe OEM bet.

On a tuned car, expect to change out the plugs every 20,000 miles - definitely not 40,000 which Porsche recommends.

 

I have a totally stock 997.1 turbo. It is a 2009 with 22k miles. How much should it cost to replace the plugs? When should I do it? I always use 93 fuel and its a semi daily driver.

 

Spooling....Prices to swap plugs will vary widely, determined by what sort of relationship(s) you have built with indys and/or dealers in your area. Expect $600 to "you can't be serious". There are a couple of other items you may want to address at the plug change to ease the pain, save some money, and please your car. YMMV. This is also a good time to get to know both your car and your local indies. In short, make lemonade. Happy Thanksgiving to you, and your family.

 

I had the plugs changed a recently for the 24,000 service. My manual recommends plug change every 24,000. I had the full 24,000 mile service done at the same time. Oil, filters, etc. Replaced the air filter ahead of schedule as well. The service ran $980 for parts and labor. I think the plugs alone were about $120.

 

My manual says plugs should be done at 30k?

 

What year do you have?

 

Don't know why but there are 3 different published intervals for spark plug change on Turbos:
2005-2007 - every 40,000 miles or 4 years
2008 - every 24,000 miles or 4 years
2009-2010 - every 30,000 miles or 4 years

http://www.porsche.com/usa/accessori...anceintervals/

 

lol...that's Porsche...got to love 'em

 

My mechanic said the old plugs looked good. It did make a slight difference in the throttle response after the service. It was like putting the bloom back on. Not to say it was ever sluggish...lol

 

I have a 997.1 turbo. I wonder why they kept changing their minds on the interval length? The cars stayed the same