Purist is saying to go back to 5w30. He's saying that because he believes it's better for the z. I don't understand why it's better. I don't understand why there is less valve train noise with the 5W30. All I want is what's best for the car.

Nissan recommends 5W-30 for the Z. Nissan recommends 0W-40 for the GT-R. The two cars aren't really in the same league, so I'm not sure why you're questioning whether 5W-30 is really better for the Z. Nissan recommends it for the car they designed and built - what more do you want? It sounds like doing the research yourself is the only way you'll be satisfied with an answer.

I understand that Nissan recommends the 5W30 for the z. I don't yet understand why the 0w40 is not better. They may see not need to pay extra for the 0w40 but I still haven't heard which is better. I have heard what's good but not what's better.

Shamrock, I'm curious as to why you didn't do your research before hand on wanting the oil that is put in the GT-R. Both cars are completely different & in different leagues to begin with. It is like wanting to put oil from a Ferrari 458 Italia into a Fiat 500 Abarth even though Fiat owns a percentage of Ferrari. Stick with what is recommended, or just go with synthetic oil from Redline, Mobile 1, Valvoline & etc........

My friend has owned a Z for two years and he told me to ask for the gtr oil. The oil I put in is Mobil 1 but 0w40 and not 5w30. The only question is what is the difference between the two besides viscosity? Which protects the engine more? One has an ester and one doesn't? Guys, from a purely mechanical point of view which is better for the z? Who cares about value. Who cares about dealer recommendations. Which is the better?

It really depends what sport you enjoy the most - if Golf is your thing then choose the 0 but if baseball is your thing then go with the 5. :rofl2:

Now stop hi-jacking this thread - it's meant to discuss Miles vs Time. :tup:

Why don't you ask your friend since he's the one whose advice you took originally without your own research? :ugh2:

:shakes head:

Shamrock, you've completely hijacked the thread, and I don't see why you still post on this thread when you've got your own specific one for your specific question.

Unless you care to do the research like many others have, anything that anyone might tell you could be true or false, and either way, if you don't understand what they're saying, you don't learn anything anyway. You might even learn the wrong thing.

Here's what I can tell you.

0W40 is thinner at cold temperature, and thicker at operating temperature. This is only in comparison to 5W30, which is a bit thicker at cold temperatures and thinner at operating temperature. I recommend running a generally thinner oil since it has to do with how motors are manufactured and how the Z typically runs a hotter oil temp and various other miscellaneous factors that would be lost on laymen such as us. I'm not even sure if I'm completely correct in saying that. Hence, I would recommend 5W30 Nissan Ester Oil, as it is the factory fill, is not some cheap dino or baseline synthetic that comes on a Camry or similar, and because as far as I know, the oil was specifically created for use in the 370Z. Forum members have also noticed a much quieter valvetrain, and for that reason, is good incentive to go with the OEM fill. After all, why would the manufacturer recommend a specific oil or even a specific oil weight if there was no reasoning behind it?

Mobil 1 is not ester, period. I stated this in your thread.

My understanding of Nissan ester oil is the micro diamond particles and not so much the ester that makes this oil unique for the Z. The diamond particles in the oil will polish the bearing journals with continued use. The smoother finish on the journals will reduce friction and hence, reduce heat. I don't use this oil. I use Mobil 1 5W-30 and my drivetrain is quiet.

Oil Changes
 

I to have very few miles so I change right prioir to Winter storage and in April.

Viscosity is very important. Nissan engineers designed your engine to run with a specific viscosity. Read the manual and determine which is the right viscosity for your climate. Oil flow is critical although a lot of people think the oil presure is the most important. They try to fix low oil pressure by putting in thicker oil which raises the oil pressure and reduces oil flow. Now the oil doesn't get to where it needs to be and the oil that is there doesn't get replaced as quickly with fresh oil. Oil temp is also very important as that is what determines viscosity to some degree. Bobistheoilguy is a good web page if you want to learn about oil.

Quieter valve train, smoother reving, etc is a poor analysis of how your oil is working. It's very subject to to many variables especially the power of suggestion. Send your oil to the lab for testing and research independant lab results on used oil from other 370Z memebers as well as VOA results...... which brings us to a point actually related to this thread. Has anyone had results from any of the labs for oil that has sat in the vehicle for extended periods of time (eg low useage/mileage 370Zs)?

I sent Blackstone Labs the original ester oil with 1,173 miles on it (after 4+ months of driving) and the replacement ester oil that had 1,963 miles on it (after 7+ months of driving). The original Redline is still in it from March '11 with about 3,000 milies on it - I'll change that out on Memorial Day weekend and send the sample in for analysis. I'll post those results which should show all 3 sets of data side by side.

like to know
 

That would be great to know since mines low mileage.

When I sent my initial oil change out for analysis (~1100 miles or so), and then compared it to my NEXT change (~4000 miles), Blackstone found a significant amount of the block casting materials were missing in the 2nd sample.

All this did was confirm to me that I dont want that junk swirling around my engine for the 4000 or so miles that Nissan recommends before you change the oil during break-in.

Oil change is done, sample is taken, and I will mail it out on Tuesday. I'll post up the report once I get it back.

:tiphat:

As promised, here is the oil report that came back:

http://www.the370z.com/members/linpa...abs-sample.jpg

I did add the Stillen G3's during this sample so I'm guessing the silicon came from the new air filters on those - not sure why it was even raised given that the silicon is much less than the previous sample. Other than that it looks pretty good - if I stick to his suggestion of 5,000 miles, this oil will stay in the car for almost 2 years. I doubt I'll do that, but would be very interesting to see what would happen - any volunteers? :bowrofl:

+1 :tiphat:

Wow, 14 months and only 3100 miles? I change every six months regardless of mileage. What does your odometer read?

Guessing the silicon may have come from fine particles of sand. Blackstone suggested this in their comments - abrasive silicon. Check your air filter for damage or not fitted properly.

You could actually add it up from the oil report since all 3 of them are shown - I'm at 1,173+1,963+3,124 = 6,268 - actually drove the car this past weekend so I am right at 6,300 today.

Will do - just seems odd that the amount is half what it was last time after 50% more usage - maybe I'll give them a call and see if he was looking at the wrong row or something. Wouldn't be unheard of to find "abrasive silicon" on the west coast of Florida. :bowrofl: Thanks!