Did you know that our Cayenne Turbo’s (955) have a 40k mile spark plug change interval (Cayenne S are 60k)? My car recently started missing and stumbling when the engine was cold and I knew my coils were fairly new so I decided to look into the spark plugs. When I found out about the 40k spark plug change interval (18k miles over) I was pretty surprised. After changing the spark plugs my cold idle miss and stumble are completely gone. It's pretty remarkable how much better the car runs now after this simple service. If any of you are having similar symptoms, definitely don’t overlook something as simple as spark plugs. I hate to sound like a salesman on this, but changing the spark plugs has probably been the single best improvement I have made to the car yet, which tells me my plugs have been bad since day one of my ownership (46k miles). Does anyone know what the factory plugs are that Porsche uses? The ones I pulled out were made by Beru. I did make a DIY video on youtube if anyone needs any help changing them.

 

I always used the ngk plat. that are like 4 bucks each and they work great, just as good as the beru.

 

One of the first things I did to mine was replace the coils and plugs. I think I used Bosch but I'm pretty sure Beru are factory equipment. Next time looks like I'll be looking for the NGK.

 

Ok, I thought the Beru were factory original. I think they were original in my car for sure. I might even lower the service interval from 40k to every 35k because the difference in drive-ability/performance was huge. I'm very happy with the Denso plugs I went with.