My understanding is, that deposits build up in your engine. Some of those deposits act as a "gasket" on aging vehicles. In spots where original seals may have sprung a leak carbon or coke may build up and actually prevent the leak from being apparent. If you change oils the different properties (detergents, weights, viscosities) may loosen some of those deposits and cause a leak to begin. In a new engine this is obviously less of a concern. I've even heard that you should flush your engine with kerosene before changing oils to clean out any deposits.

I used Castrol GTX in my Speed6; it performed flawlessly. I'm planning on using Castrol Edge in my Z. I still think that 90% of all general knowledge about engine oil (including my own) is myth (flame away).

+1 Royal purple. Some say its a waste of money but many swear by it, and I use it.

Are any of these Ester Oils ?

I change oil often and use one of these....they use them at Mercedes dealerships

Amazon.com: Mityvac 7400 7.3 Liter Fluid Evacuator: Automotive

I own an evacuator like one you reference, but there are caveats as different engines will not allow their use resulting from the oil tube layout. I am hoping, but have not tried yet, that an oil evacuator will work on this engine.

I'm breaking in the engine with the Nissan Ester Oil (which is non-synthetic btw) and will continue using it until 15000 mi. After that I'll use a heavily ester based synthetic oil.

The reason being; this engine likes the abundance of esters but likes conventional oil to allow full break-in. Synthetic might do its job too well and inhibit the "break-in wear" that needs to happen.

Used Mobil 1 in my Mustang GT and I use it in little Civic sedan right now. Plan on using it with my 370Z when I get it.

Here's the problem with voting on oil; You can't see or feel how well the oil works on a daily driver. The power of suggestion plays a big role here.

If you used the cheapest oil vs. the best oil for a few years, you'd likely not notice a difference and you can't test without a control. How do you judge the oil? That being said, I've heard good things about Mobil 1 and its a decent price and easy to find.

My 2 cents.

i've always used mobil until recently i switched to Castrol, both are great.

I have used Amsoil since the seventy's, and have always had good results.

No scientific info of any kind just observation. Years ago the oil change interval was 5k. If anything the engines and oils are better now than they used to be. The 3k interval seems like a gimmick. Again all anecdotal info but my Jeep is LUCKY to see an oil change at 5k and it runs great with 200k miles.

I pick up my vehicle tomorrow and will follow the manufacturer spec for the first oil change and then change between 3 - 5k.

Since the 370Z is a sports car, Nissan most likely calculated that drivers will be a bit harder on the Z; dino changed at 3K is not so bad on the Z; synthetic at 5K will do the job too.

whats the manufacturer suggestion for first oil change... sorry im too lazy to go to my car =(

I know 4K-5K for oil changes should be fine, but I grew up changing the oil every 3K miles and I just cannot go that long. I use Mobil 1 and the car is a daily driver, but I do drive aggressive when I get the chance. No matter, once I see that odometer go past 3K miles it bugs me until I change the oil. can't help it, so I just change the oil every 3K miles, even if it is a waste of money.

I think the book says 3750 miles between changes.

I switched from Nissan oil to Castrol Edge last weekend. I haven't really noticed any marked difference in the car yet. I did notice that the oil (castrol Edge) is much darker than most other oils I have used, not that it means a thing.

On kind of a related topic... Changing the oil in this Z has got to be one of the, if no the, easiest oil changes I have ever done.

does the boook say anything for mileage on the FIRST oil change?

I think I'm going to take my Z in around 2000 miles.

^ +1 Ditto.

Hey SoCal, let us know when you find out whether or not we can use an evacuator on the Z.

Will do, as I am anxious to learn about that as well; it will make oil changes sooooo much better, and easier.

next door neighbor worked as engineer for ford for 15 years before moving to az to work for intel... he says that choice of brand has little to no bearing on thermal capacity or long-term engine reliability and that weight and viscosity are the key parameters... he claims that ford tested this for years and that was the conclusion every single time... just figured i'd share that - personally, i have no technical opinion... i'll prob just go mobil 1, b/c i used to work at mobil oil way back when

For those of you using Mobil One, I would recommend the extended performance version. It uses an ester base similar to Redline, Royal Purple, Castrol Edge and Amsoil. The regular Mobil One uses an organic base (this is the oil that Castrol Edge compares itself to in their commercials stating that it offers eight times more protection).

Mobil 1 FTW:

Mobil 1 Selected as Factory and Service Fill Motor Oil for New Nissan GT-R Multi-Performance Supercar

If it's good enough for the GT-R, should be good enough for the Z.

^After doing some more research on esters, it seems like there may be some real needed benefits that the Nissan Ester Oil brings to the VVEL system (esp. in the long term). And what's more, since we don't know exactly what esters are in the oil, you can't just go out and buy a Group V synthetic ester oil and hope it does the same thing. So, until I find out EXACTLY what is in the oil I am probably just going to stick to using the Nissan Ester Oil instead of Mobil 1, or any other synthetic for that matter.