i purchased my g35 sedan about a year ago from a rusnak dealer and decided to go with synthetic i had about 73k miles on it. i switched it over with 5w30 mobile1 and found to my surprise it was loosing a quart and a half before i hit 3k. so then i changed to amsoil Signature Series 0W-30 100% Synthetic Motor Oil and it was burning oil faster. then i switch to the amsoil SAE 10W-40 Synthetic Premium Protection Motor Oil, and its still burning oil.. what is the deal. on other thing i forgot to mention is when i initially bought the car and changed the oil i drained out 5qt every since i switch out to synthetic i been draining out 3.5 to 4qt before my 3k interval or i just keep adding oil till i hit 3k to 5k miles on the oil. could it be the engine had soo many mile on conventional oil that synthetic oil is making it consume more oil then usual. help me out guys i am really stumped. i searched the forums and only found issues with the MT g35. so i duno what is going on. i do not race the car i just use it to go to school and work and to do my trips.

well Synthetic oils are said to be thinner than regular mineral ones (some will dispute that) so they dissapear faster, I use higher mileage ones, found that quakerstate has best protection for burnoff

I would consider going to 15-50 and see if you still burn that much.

wow 15w-50 is thick i didnt know they make oil that thick.. i am currently using 10w-40 of the amsoil oil. the issue it just puzzling because i have my mother who has a 99 maxima and has 5k of the same oil and no oil consumption and the same with my fathers 01 tacoma.

Nissan redesigned engines with lower ring tension and contact area to reduce friction to increased published power output.
NASCAR engines are so loose that they burn 8-10 quarts in 500 miles.

soo what are you saying?

VQ35s tend to burn a little oil, however, 1.5 QTs every 3K miles is significant. 1/2 to 1QT every 4K to 5K miles is okay. The fact that the oil is synthetic doesn't mean it burns off quicker. It could be that you've got an engine problem or that's just the way the engine always been. I strongly suggest watching the oil levels at least every 1K miles and keeping the oil within the operating range noted on the dipstick. I'd also keep close watch on if the oil consumption is increasing.

What's your driving style? Lots of high rpm driving? Lots of highway? Lots of stop and go? Combo?

Have you checked the PVC valve for clean operation? Are you leaking oil? Do you see smoke coming out the back under heavy load or off heavy throttle?

i do normal driving mostly combo of highway and streets with stop and go traffic but mostly highway.. no i have not checked the pvc valve. where is that located? no i am not leaking oil from the oil pan at all i took off the plastic under the car and looked at the engine and it is spotless.. no i dont see smoke when i am under heavy load or off heavy throttle

The PCV valve is located on the forward passenger side valve cover. You'll see a hose heading into the valve cover. The PCV valve is connected to that. If I remember correctly, the valve simply pulls out of the cover. It's a long shot that the valve is bad as these things rarely fail.

thanks ill check it out

i checked the pcv valve and i hear a clicking noise when i shake it? i heard that it means its fine right?

i don't know if this will help but i've always been told that if a car has higher mileage and it's been using conventional oil, switching to synthetic, which is thinner, you may lose/burn more oil. that's why it's better to start the car off on synthetic from the get go when the car is new so that it adapts to the thinner oil. of course, you can't really do this if you buy a used car w/ higher mileage.

why not try conventional oil for 3K miles and see how your oil consumption is. GL

that makes sense...but i have my dads 01 tacoma and mom 99 maxima which i switched over to synthetic and both have high mileage. both dont consume a drop of oil and its been 5k on the oil. yet our cars are prone to some oil consumption. ill try your advise at this point i am willing to try anything to stop the oil consumption and me spending money every other week on a quart of oil. i also heard its bad to switch from synthetic to conventional ? that true

^ hmmm, i'm not sure about that one. hopefully someone else can chime on that.

i don't know where you're located but you can also call a reputable performance shop and ask them or just get several opinions.

My 2004 G35x owners manuals specifically says not to use synthetic oil. Don't know why.