E46 Spark Plug change - How often??

[Over Clocker]

Hi guys,

Does anyone know the recommended mileage interval for spark plug change on an E46 320i (2.2 6pot)?

Cheers,

Mal

 

[Over Clocker]

Hmmm... Any benefit from changing them more often?

 

[Over Clocker]

Also, is the "lifetime" gearbox oil really lifetime?