Stop using Mobil 1.
Shell Rotella t6 5w-40 or Castrol Synthet,
I've gone to using Amsoil European 5w-40.
I've been using the same K&N kit I bought back in 2005.
178,000+ miles, 5/20/12 new ej257 short block, 8/20/11 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. CHECK your oil, these cars use it.
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