'95 993 Spark Plug Change Interval

[NC TRACKRAT]

Porsche Maintenance Schedule lists spark plug change for the '95 993 at 30,000 miles. Almost every enthusiast site I've visited talks about changing plugs at 12,500 or 15,000 miles. What's the rush here? I'm as much a fanatic about preventive maintenance as most but this seems excessive, especially considering the difficulty of the job on a twin-plug Porsche. Opinions? Consensus?

[stubenhocker]

Porsche Maintenance Schedule lists spark plug change for the '95 993 at 30,000 miles. Almost every enthusiast site I've visited talks about changing plugs at 12,500 or 15,000 miles. What's the rush here? I'm as much a fanatic about preventive maintenance as most but this seems excessive, especially considering the difficulty of the job on a twin-plug Porsche. Opinions? Consensus?

In the excellent book, PORSCHE 993 The Essential Companion, on page 139, MAINTENANCE SCHEDULE says 12,500 miles for spark plug replacement.

[NC TRACKRAT]

Porsche Maintenance Schedule lists spark plug change for the '95 993 at 30,000 miles. Almost every enthusiast site I've visited talks about changing plugs at 12,500 or 15,000 miles. What's the rush here? I'm as much a fanatic about preventive maintenance as most but this seems excessive, especially considering the difficulty of the job on a twin-plug Porsche. Opinions? Consensus?

In the excellent book, PORSCHE 993 The Essential Companion, on page 139, MAINTENANCE SCHEDULE says 12,500 miles for spark plug replacement.

I've got his book and I've read just about every site on the internet. I'm just saying that PORSCHE officially says 30,000 miles. Why is everyone else splitting that in half?