03 I35 Spark Plug and maintance questions

[I35JUGA]

I have 2003 I35 with 105k, want to repalce the spark pugs, and the dealership said that i have to replace the plenum gasket as well, is that true ? and which spark plug that you guys recommend ... also which transmision fluid you guys recommend ? or OEM is better, thank you

[WDRacing]

If you have to remove the plenum to gain access to the plugs then the gasket will need to be replaced. If not, then don't worry about it. Always replace a gasket on a part that has been removed.

I recommend NGK plugs.

Trans fluid type will be arguable because some people prefer boutique lubes and some prefer the cheapest and some swear by OEM. The best is Amsoil, but it will have to be ordered and delivered. If you have a preferred brand, like Mobil or Royal Purple, go to there webiste, entre the model information and they wll list the best product they make for your car. Amsoil has a great site.