I looked into changing all the fluids to synthetic also.
Here is what I found out:
The G35 Automatic transmission requires J type, anything
else will void the warrenty on the 5AT.
The G35 differentail oil is a synthetic blend from the factory.
Infiniti does not recommend full synthetic in the differential.
That left me with only the engine oil to go with synthetic.

2003 Twilight Blue 5AT Sedan, sunroof,
Graphite Leather, splashguards,
GG/DB red 12 wire Hyper-grounding kit,
350Z intake duct, Stillen Hi-Flow Airbox

 

For those whose using AMSOIL (http://www.amsoil.com) on their G, which one are you using?

SERIES 2000 - SAE 0W-30 Synthetic Motor Oil
SAE 5W-30 XL-7500 Synthetic Motor Oil
SAE 5W-30 Synthetic Motor Oil
OR
Royal Purple? (http://www.royalpurple.com)

 

Then what oil should i use for G35 coupe manual transmission fluid ??and the LSD?


2004 IP/Blk G35C 6spd navi/aero/prem

 

i switched over to Mobil 1 right after my break in at about 500 miles. i went with a 15w-50 its the one with the red cap. its perfect for mild climates or if your not goig to be driving your rig in the snow. either way synthetic isnt prone to gelling like convention oil and because it has better clinging qualities you wont have to worry about dry starts. deffinitely worth the extra $ in peace of mind alone plus if you drive your G like most of us on this site ( right foot to floor mat ) your power pump (engine) will need it. that wasnt meant as an insuly

 

Wow, 15w 50 is pretty steep for our vehicles. I would say it is probably not good for our engines either. It seems like you have it backwards, too. The heavier weight oils were conventionally used for "extreme" condition vehicles, such as blown or nitrous applications. I wouldn't use that on my car. Newer vehicles are designed to work with lighter grade oils, and doing otherwise will hurt fuel economy, and put excessive stress on the oil pump.

'03.5 Brilliant Silver Sedan
Premium, Aero Kit/Package, Sport, Winter
Stillen Air Box, Z pipe, Clear Corners, Alum Pedals
Polk Tweeters

 

I just put AMSOIL 5W-30 this past week. Since then I have noticed that my coupe is a little faster, a whole lot smoother, a whole lot quiter. I absolutely love the way my car is performing. But I am missing the noise though but hopefully the CAI I am going to install will revive that noise some for me again. I am going to go 7500 miles between oil changes and it will cost me about 5 dollars more than using the old hum drum oil per oil change. While I was waiting for my oil change I took an M3 for a spin and I surely noticed the smoothness and quietness by it. I was incredibly surprised by that. As I drove my coupe for awhile and I could tell that my car was getting so smooth and quiet and a lot closer to the smoothness and quietness of the M3. The Amsoil effects on my coupe are very exciting.

 

Has anybody tried changing an oil filter without changing out the oil? Does it make a bit mess to take the oil filter out without draining the oil pan first, or does all the oil collect below the level of the oil filter (except for what stays inside the filter)?

2003.5 G35 Sedan Desert Platinum/Graphite Premium/Sport/Aero/Nav/Winter