Hi,

I'll jump right into it. I have a 2007 350Z HR, with 22.000 miles. When I got the car 6.000 miles ago I changed the oil and filter. As usual I asked for Nissan OEM oil. And what I got was
Motor Oil Strong X, 5W-30, API SN, ACEA A3/B3.
I cannot confirm if it's full Synthetic or half. Information vary. This oil is made by Fanfaro, Germany. They also make specific oils for Nissan's diffs (and transmissions). Picture bellow.



After using this oil, oil pressure was OK - idling warm at 28 PSI. But I noticed if I go for a spirited drive on a Touge oil pressure would drop significantly to 15-16 PSI idling. Due to the fact on cold start oil pressure is almost 120 PSI, I am excluding oil galley gaskets. For now and at this mileage.
But anyhow after research I found out that here in Europe this is not the same oil Nissan Dealers are putting in. Packaging is different and as far as I managed to get the info, Nissam OEM is Elf (maybe even Total). So I decided I will go with different brand of oil. As per many posts up here I decided on Mobil1. I know, most of you go with Mobil1 0W-40, but wanted to do a check how this oil will perform. As I would like to do some oil comparison I went with:
Mobil1 5W-30 ESP, API SN/SM, ACEA C2/C3.




Please note, Nissan does not specify which ACEA oil to use for 350Z in the manual. Though at the Dealership they use Fully Synthetic oil, not Ester based:
NISSAN MOTOR OIL 5W-30, API SM/CF, ACEA C4.




So, how did Mobil1 5W-30 perform on first drive, with fresh oil? To put it short - the same. I also saw PSI drop on spirited drive AND also a bit lower pressure - compared to Fanfaro - when driving in City with congested traffic. Honestly, I am surprised. I would have though Mobil1 will keep the pressure stable. In the end, Nissan is saying 5W-30 should be enough.
I also sent oil samples of Fanfaro to the lab and I wonder what will come back.
I guess my next step will be 0W-40, Mobil1, which is rated even higher, more performance oriented as it follows following specifications - Nissan Genuine Performances, Porsche A40. And as for API CF, SJ, SL, SM, SN and ACEA A3/B3 and A3/B4. Taking into account API and ACEA Mobil1 0W-40 seems more suitable, but viscosity is different.
At the end I would also like to engage you in this conversations. Do you also get lower PSI when driving hard? Does the PSI drop like that? I am not sure it should.
And those using Mobil1 0W-40, what kind of oil pressures you get?

 

Since Nissan is in the car biz they obviously sub-out oil and packaging to that industry. Packaging will vary from region to region and year to year.
To answer your question yes, psi for oil pressure will vary widely as a factor of temperature. "Viscosity" or thickness is always a function of temperature in liquids and suspensions. Consider water's viscosity. At 72F it's a liquid. At 212F it starts to become a gas and at 32F it becomes a solid so yes it's completely normal for your oil pressure reading to drop as the temp goes up.

 

I know this is a few weeks old but let me make it clear:
on cold starts, the oil pressure will of course be higher than normal. Anywhere between 60-100 psi as the oil is cold and thicker, so the engine needs more pressure to push it through.
When it gets to normal operating temperature (hot), it becomes thinner and less pressure is needed to push the oil through.
As you accelerate, the higher the RPMs go, the higher your oil pressure should go.
At normal operating temperature, the oil pressure at idle should be around 14 psi. At 2,000 RPM, it should be around 50-60 psi. At 6,000 RPM, it should be around 75-90 psi.

 

I'd be curious to see how the M1 ESP performs in the HR from a UOA standpoint. I use ESP in my subaru because it performs really well in the FA20 motor. I used 5w30 M1 religiously in my HR for 30k miles but I just switched to Castrol 0w40 for my most recent oil change.

 

how's it differ so far?

 

No perceptible difference between the two. I've only had the castrol in the car for about 50 miles so I'll have to see how it looks on an UOA once I've put more mileage on it.