Just got a new 2012 g37x. I drove a 2002 stock 6 mustang for 10 years so I am very excited about the increase in performance and just an overall nicer car. Just so e questions about gas and maintenance. Should I change the oil 3500 or 5000 miles? Also what octane should I put I . My dad's C300 uses 91 so I'm not sure to put 91 or 93 in mine. Anyway thanks. I'll post pics in a week or so when I pick her up.

 

91 Octane is just fine and without Ethanol if you have a choice.
I'd change regular oil @3500 miles and Synthetic at 5 to 7,000 miles.
Congrats on your new G and welcome to the site

 

Congrats on your new G! Definitely a nice upgrade you got! Post pictures when you can for us

 

If all goes well I should be pulling the trigger on a 2012 g37x sedan tomorrow... Can't wait! Looking forward to learning from the experts on here...