Hello everyone, I just picked up a used 2005 G35 sedan black on black fully loaded with navigation and sport package and am loving it! I am the second owner of the car, it only has 20,000 miles on it. I am concerned what kind of oil was used with the previous owner and what kind of oil I should be putting in either synthetic or dino. If I look at the maintenance info on the navigation system it displays about 1500 miles have been driven since last reset (hopefully it was reset at the last change). Also the change interval is set to notify at 7500 miles, which leads me to believe it has synthetic. Do they put synthetic in these from the factory, or a semi-syntheic? Is there a way to tell if it has synthetic in the car, probably not? After figuring out the unique dispstick lol, I noticed the oil is very light in color. Ive been told synthetic is very light in color, idk if this is true. I dont mind switching to synthetic, but I havent been fully convinced. I also dont want to reverse the process by putting dino back in if it was previously switched to synthetic. Thanks.

 

Synthetic is pretty close to clear I use to use synethic in my Maxima but I've been using regular oil as of recently but have used synethic blend before in my car. If you want to save $$$ go to regular or syntheic blend it won't do any harm.

 

There's nothing you can do about what happened to the car in the past.
Just change to synthetic or any main brand conventional oil if you are afraid that previous owner was using Wal-Mart brand-that's the best you can do.

 

I just started doing my own oil changes after my first 2 at the stealership and Im using Amsoil 0-30 and the maxima Amsoil filter and myself and my brother have noiticed MPH increase of about 5 after switching. (He switched at the same time in his 03 Maxima) I only plan on running that thin of a oil inthe summer but hopefully thenumbers will hold up when I switch to a heavier weight in the fall.

 

I used to put in fully synthetic 10W-30 Mobil-1 oil in the G during the first few oil changes after the purchase on Sept. 2006. I would change that oil every 5000 miles. However in my most recent oil change I decided to switch to regular 5W-30 just to save a little bit of money. There's no problem at all in going from dino to synthetic, and vice versa.

 

"MPH increase of about 5"??? can you clarify if this is at top speed, 1/4 mile trap speed, or other?

or did you mean MPG? i would expect a slight improvement, i.e. 1-2 MPG, but 5 is a massive increase...

 

Sorry I meant MPG 5 may be high but its dang close to it.

 

thanks for the replies..I will most likely switch to synthetic oil next change. Im going to do it myself, and make sure I keep the reciepts! I am leaning towards Castrol full Synthetic 5W-30 with a Wix filter. Just spent an hour reading through all of the oil threads here and other forums, I think Mobil1 just isn't the best oil for the VQ35. Anyone know where I can pick up some castrol for good price? Autozone?

 

i don't think autozone carries german castrol. you can check. try napa

 

I have found GC at AutoZone before.

 

Personally I like to pour a bit more money into the oil/filter and save $$ else were so I use synthetic Royal Purple 5-30, you can probably only get at Marrey's, I know autozone had it for a while. Its almost $8 per quart but its worth it. As for filter I use Mobile-1, forget the name but its like $12 or something. +hp +mpg better 4 engine.

 

what about just the regular Castrol full synthetic 5w-30 (not the german formula)? Anybody running that in their G?

 

how many quarts does the G35 require? i ask because an is350 for example uses 8 quarts

 

5 is the answer.

 

Walmart sells 5qt jugs of Mobil 1 synthetic for around $24. I'm sure they have other brands in that money saving size as well. With the money I save by changing the fluids myself, I bought a nice floor jack.

Normally you would want heavier in the summer and lighter in the fall.