Porsche ssuggests 40K miles for sparkplug change for 997 turbo. Besides the +$1K charge and half tearing your beauty apart, wonder if plugs can't go to 50-60K without issues?
I've noticed in many HP-engines over the years, plugs last much longer today...some to 100K especially with clearner fuels and highly efficient ignition systems plus improvements in spark plug design.
I'm at 40K with no symtoms like surging, hesitation, low mileage or hard starting. Acceleration is still exceptional.
For those getting plugs changed at 40K, have you noticed any difference from the old plugs over new ones like even an enlarged gap? Have you noticed a change in performance, mileage etc?? To me. seems like an exceptionally short life for a plug even if firing a turbo (talking street driving, no race track stuff).

 

Alot depends on how you drive, another factor using anything less then 91 octane can
make them wear out quicker..

I was a mechanic for 25+ years and even when cars where supposed to have them done
every 30k ..i would see people stretch it to 90k now there was not much left at that point.but car still ran fine.

if its not missing you should be ok. If it does start to miss you would want it done right away .

 

My 2008 tt is a daily driver. I had my plugs changed at my 2 year service (24k miles) and noticed a difference in the engine performance.

 

its all butt dyno but I noticed more of a change cleaning my MAF units, no joke, vs. swapping out the plugs around 20k. Used that recommended CRC spray stuff from the auto store.

 

11K miles, ECU/Exhaust, no perceivable problems in daily driving.

 

Good grief, if a noticeable performance difference occurred in that short of time, Bosch needs to do some engineering and redesign their turbo plug with all the trouble + cost there is to replace them. Wonder if you noticed if even the gap was widen on the old set or bad discoloration or if the tech said there was a problem with any plug?

 

johnww. My understanding is the plugs should last as specified if the car is not modified and remains stock....correct fuel is used etc. However once an ECU file is modified (tuned) the environment also changes within the cylinders and the plugs life becomes shortened. The gap in the plug becomes more critical. Most of these guys changing plugs have a tune file and therefore seek to optimize the life of the plugs and, the performance of the tune, by ensuring the gap is in best keeping with the tune.

 

If your tweaking the car, the plugs will burn hotter and it will shorten the life,

 

No sh...t! HAve to change mine every 5-10k kms!!

 

Wow! I was told to NEVER attempt to clean those MAFs as they get destroyed..
Just had to change my first set at 40k kms (modified car)

 

You may not even notice you need new plugs unless the car is under load, the track for example. One day at pocono, my car was running like crap, backfiring between shifts, no power, CEL on the way home. Up until that outing, it seemed to run fine (tuned).
I changed mine at~30k at the time, now I'm due again. This time I'm going to DIY, last time let the dealer do it (painful).