Using 5W-40 on Z's with no oil cooler

brainrain

Nissan dealer in south of France recommend 5w40.

I was a little surprised because all people in this forum recommended 5w30 oil, despite the high temperatures in summer in the United States.

I discussed with some owners in France, most use 5w40. But we aren’t many to have a feedback on the reliability of the engine with this oil.

SouthArk370Z

How many auto engine engineers work at the dealership?

As the chart above shows, once the temp gets over 100C or so, the difference in viscosity is very little and which viz you use is not that important.
Below about 60C, the difference in viz can cause higher pressure, more strain on the oil pump, and a little less flow through the system. Moving up 10 probably won't make much differerence unless you really push the engine when cold, but why risk it.

This is for DDs. You track guys operate under different conditions.

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brainrain

They can't even solve my problem with my keyfobs ...
and they did not see much nissan 350Z/370Z

I don't know how people drive in north america (smoother driving or aggressive driving) but in France many Z owners drive only on weekends (with aggressive driving ).

I would use Mobil 1 5w30 Esp Formula because he have a high HTHS rating.

FL 4Motion

Why not just add an oil cooler, run factory rec 5w30 and not have to worry about excessive heat issues? Wife and I only ran M1 0w40 bc it was more track car than daily driver.

If you’re not tracking, then a 19 row oil cooler will be just fine, or even a 25 row. 34 row is only necessary if you’re gonna go to the track, or if you live in ME.

Zyonara91

Exactly. I run a 19 Row out here in Toronto, it handles traffic, spirited driving coupled with hot weather just fine. I do not track hence the choice.

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