Are we talking in general or just on G35's?

 

I will say this from personal experience - using a full syn oil and quality filter, it is more about mileage than time. Example: I winterize the Volvo Penta 5.0L in my boat in October (full syn 30W or 15W50 is changed with a new filter). The recommended maintenance is that this oil sits through winter and is used the next summer - usually 30 hours of summer use in my case . In October, the oil is changed again (along with other winterizing procedures). The oil and filter look perfect a year later - almost looks like I should just leave it in. Obviously, this is a V8 with a WOT at 4500 rpm but still, the full syn is subjected to sitting for weeks, months at a time...harsh "marine" conditions, etc. I really don't feel it breaks down much at all. Same for the full syn gear oil in the lower unit. Of course, the oil companies would prefer a more "aggressive" maintenance schedule, I'm sure...but I think you can change every 7500 miles within reason (i.e. 18-24 months).

 

I always change my oil myself, just don't trust others to keep from cross threading the plug, overfilling, etc. Such a simple DIY (especially w/ the trap-door flap). I change every 3750-4k w/ 5.2 qts of Mobil 1 5w/30 and Mobil 1 filter. I usually stock up w/ a years' worth of oil & filters when OReillys or Autozone has their Mobil 1 5qts plus filter for $29.99.

Changing full synthetic every 4k is much sooner than it's real "shelf-life" but for $30 a pop it's no biggie, and gives me a little piece of mind changing every 4k (especially like previously mentioned) the filter is so damn tiny

 

Chang intervals should be deturmined by your driving habits, time, and miles. The WAY you drive has a big factor on oil life. Whenever I was on the road to the tune of 5K a month, my oil looked as clean at 3000 miles as it did when I put it in. If you drive at least 80 miles a day, it will keep the water and acids boiled out. You can run your oil much longer.

 

lol i change every 3500mi or so cause i do it every 5k.

but recently i've been driving less so it's been a few months since i've changed my oil.

 

i am talking about on the G35. I drive about inner-street most of the time, and am NOT an aggressive driver.

 

I change oil every 5K (use Mobil1 with Purolator PureOne filters), and rotate my tires around the same time. Can go longer on the oil, but would rather not chance it and it is convenient to do and remember both.

 

I change mine every 4-5 months b/c I only put about 3-4k miles in 5 months.

 

changed my oil when I got the car at about 25,5k miles. 4k miles later, thinking of getting another one soon.

 

I am getting the impression that these cars do not come with syn, which I find amazingly cheap for such an engine.

Those of you running syn oil what weight are you using? I have used Mobil 1 0w-40 in other cars without a hitch. My next change in this car will be with M1 0w-40. I just changed in my 08 at 15000 (this is my 3rd change 3750; 7500; 15k). I will make the change in 5k miles.

 

Infiniti recommends 5W-30. In the case of Mobil 1 I have looked up the 0w-40. First off no problem with the 0w since from my research for most oils it gives possibly another 10 degrees on the cold end for pourablity. Mobil 1 30 and Mobil 1 40 both sit almost dead center on the viscosity scale for their ratings. A 40 can actually increase your engine temperature a little bit compared to a 30. On some cars it may give slightly better protection on the bottom end of your engine but sometimes that is traded for slightly less for the top end of the engine. So some of this has to be determined on how you drive. For the typical driver I would stay with 30 weight on a low mileage car.

As far as intervals right now I am doing 5k changes. I figure the oil life is not the issue, it is the filter. 5k should be well within the range of the filter and is an easy number to remember without waiting for the car to tell you. But then it just comes down to how you drive and how warm and fuzzy you want to feel.

 

Thats why I do 6k mile intervals but change the filter every 3k. Changing the filter is pretty cheap and easy insurance.

 

I personally change mine so frequently because I do a lot of stop/go traffic driving, with frequent high speed acceleration/deceleration.

I know you can't judge the oil by its color, but at 4-5k mine looks terrible.

 

This is where an external oil cooler/filter setup would come in handy. You could go until you see evidence that the filter is not doing its job. I really want to look into this as to me this would be a fairly easy mod and one that would be hard to argue against as far as being beneficial.