Z Oil Change: Miles or Time?

JARblue

From his link above, the GT-R uses 6-quarts Mobil 1 Synthetic 0W40. For the Z I use 5W-30, which is recommended by Nissan. If you have 0W40 in there now, I'm not sure whether you should immediately change it out or not. I know I would just because I'm like that, but perhaps someone else can weigh in with a more precise answer.

I believe it is "ester-based oil" and there are numerous threads on this topic already.

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370Z Purist

Typically a heavier weight oil is better suited for warmer or hot climates. A few people who drive in colder weather will convert to 0W-20 or 5W-20. I personally run 5W-30 since it's the recommendation, and since I typically warm the car and the oil to at least 180 until driving harder (keeping RPM under 3000, etc.)

There's no real need to change that oil immediately, since you're apparently in Israel and I'm guessing it stays pretty warm there.

Ester oil is nothing really special; it's any synthetic oil with an added ester base. In the Z it will reduce or eliminate valvetrain noise. It's also reputed to be more durable for higher performance engines, but proof is far and few in between.

I also noticed you started a new thread completely. The things that members have written there are good pieces of advice. Me, personally, I'd just wait 3k miles and change the oil back to 5W-30 using whatever oil you want. I'd stick with a synthetic, and this way, you don't waste your new Mobil 1 oil.

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-Phil

"Since one of my brake light bulbs just went out, the forum told me that my piston rings are about to blow."

Shamrock

Purist, I don't understand why you say to stick with a synthetic my next oil change as to not waste my Mobil 1. Also from what I understand Mobil 1 is ester based. 1. Why is 0W40 used in the gt-r if technically 5w30 is better?
2. Is it ok to go back to 5w30 after 0w40 or will it affect my engine seals?
3. Isn't the difference between the two oils that the 0w40 is better for cold starts and has a thicker viscosity at higher temps? If so why is this not preferable?
4. What does this mean? "all 0w oils lose ability at operating temperature to enable them to get down the the 0w acting?

Totally confused here

JARblue

I didn't see anyone state that 5W-30 is better than the 0W-40. And I certainly didn't see anyone state that 5W-30 is better for the GT-R.

It's fine - it won't affect your seals.

Bob the Oil Guy is a wonderful resource to better understand these differences.

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Shamrock

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.

JARblue

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.

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Shamrock

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.

MacLean

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........

Shamrock

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?

FricFrac

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)?

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LinPark

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.

rebe945

That would be great to know since mines low mileage.

MightyBobo

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.

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LinPark

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.

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

JARblue

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

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