I’ve read through the posts thus far and have come to a few conclusions. First, I question that there is an ‘issue’ with oil temperature. The Owner’s Manual, page 2-7, states that if the oil temp reaches 280F, slow the engine down to reduce the temp of the oil. The Nissan engineers must feel confident that the engine oil temps below 280F are safe for the engine to operate when using the recommended oil, API SM and not driving the car in ‘off road’ mode e.g. pushing the car to its limits on the track. Warranty does not cover your engine for off road use as most of you are aware. The warranty will cover you if your engine fails under ‘normal’ use provided you didn’t keep driving while the oil temp was above 280F. So, where does this figure of 280F come from? No doubt through extensive testing of the engine under conditions that none of us will experience in ‘normal’ use. What are the specs for API SM oil and how is that determined? SWRI is a company I did some brief reading about and found that it has a standard for testing oils and I assume for determining the standards for API approved oil specs. Without going into too much detail, one of the tests they performed using API SM oil was running a GM 3.8L engine for 100 hours with an oil temp kept at a constant temp of 300F. What does this tell me? To me, it says that the Nissan engineers know what they are doing. They know the engine will operate satisfactorily for the spikes in oil temp up to 280F under ‘normal’ driving conditions. Above that, they have incorporated a limp mode to reduce engine speed to protect the engine’s integrity. Will failures happen at oil temps below 280F? Most certainly but perhaps only a very, very few. Will it be due to the oil or its temp? Who knows? Not every component manufactured in a mass produced engine will be 100% perfect 100% of the time. If you don’t trust the Nissan engineers in stating that anything below 280F is a safe temp using the recommended oil and choose to believe that even 260F is an unsafe temp, then you might also be suspect of the engineers who designed the next bridge you cross. I don’t second guess mechanical engineers or any other engineer who holds a professional designation if I am not a professional mechanical engineer myself. I will still be buying my 370Z this week and will have fun driving it. If the oil temp consistently reaches 280F as stated in the manual vice 260F, I will have an ‘issue’ but not until that happens. Any mechanical engineers in this forum willing to come forward and challenge the 280F oil temp as determined by the Nissan engineers and state that 260F is indeed an issue?
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