Z Oil Change: Miles or Time?

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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I don't own a car anymore.