Spark plug life

[Gangplank]

N52 @ 100k
N55 @ 60k
N54/N55w PPK @ 45k
N54 or N55 tuned @ ?

If the motor is tuned for more HP the plugs should get changed out sooner. Personally I change mine out a bit sooner depending on what maint I'm doing. Old plugs sap power, can cause the motor to run rougher and wear coils faster.

[KNS]

Originally Posted by wolfe

I'm told that as the plugs wear and the electrode gap gets bigger, the ECU works the coils harder to create a good spark. This causes the coils to wear out which is what happened to my car.

My E46 has 200,000 miles and has been extremely reliable. I was talking with a mechanic the other day and I mentioned that I've never changed the coils or had any issues with them (I'm the original owner). He asked how often I changed the plugs and I told him every 60,000 miles. He said: "That's why your coils have lasted so long" and stated the exact reason above and said 100K is a long time.

Perhaps the interval should be even less miles on an E82.

He also asked what plug I used and I said always NGK. He said he sees more problems with Bosch and almost never any problems with NGK plugs.

[markslc1]

I just replaced mine with bmw brand at 52k. Immediately solved my serious hesitation problem. +1 for making this the first thing to try if the car isn't running right.