Mobile 1 Synthetic Oil ? or Penzoil 30-5W? please help

i use royal purple

^ +1 I run ROYAL PURPLE...Mobile 1 is also a very good choice.

i used penzoil 30-5w once is that okay?

yea its ok but i used Mobile 1 extended performance. only change it every 15kmiles and its guarnteed to protect the engine for that long and he has increased my mpg on other vehicles up to 2mpg

Amsoil all the way. The original and best synthetic out there.

https://www.amsoil.com/storefront/sso.aspx

Extra Virgin Olive

Its such a subjective topic that you should just go with whatever oil you feel like you can afford and how often you want to change it. Any major brand oil somewhere around the recommended weight (5W30) will be fine. Run synthetic if you want to extend out your oil change. The best info on oils is over at Bob is the Oil Guy

FWIW I ran conventional castrol GTX 5W30 until my last oil change and now have switched over to Castrol Syntec 0W30 (German Castrol). If you want to go full synthetic, all the major companies have decent products (Castrol, Mobil, Pennzoil, Amsoil, Royal Purple, etc). I haven't seen an oil yet on a G35 that has been proven to have caused engine failure.

I've been using Mobil1 Synthetic for over 2 years now.
Just recently I switched to ELF Synthetic Oil..

BOTH, are awesome.

Due to the rough economic times I have secretly been buying the "off" brand vegetable oil, hiding it, and then filling up the expensive olive oil bottle in our kitchen. My wife hasn't even noticed. I suggest everyone else do the same.

I've used both dyno and synthetic and the bottom line is that all of my cars have exceeded 300K miles (1 ancient Datsun pickup, three 240D Volvos, 1 VW fastback) on dyno, which suggests that it's not necessarily the oil (unless you buy the really cheap oil such as WalMart's Tech oils). Currently use Mobil 1 on the G; however, the issue may not be which brand or type of oil, but how you drive the car, how often you change the oil, your attention to maintenance issues that affect oil's viscosity, corrosion inhibition, cleansing abilities and and other factors. Mobil 1 netted me an additional 1-2 mpg on my 2004 sedan (currently at 28mpg highway @ 70mph and 23 city).

Interestingly, the market is beginning to produce biodegradable oils - formed from the fats of cattle. The environmental benefits are clear, just not sure how effective it is as a motor oil.

That's fine, just be sure to change it at the recommended interval and use a good quality filter like Amsoil/Wix/Mobil1/NAPA Gold