I use GC 0w40 with a K&N oil filter. What is the OEM spec oil weight anyways?

 

^
you mean Mobil1 0w-40? b/c last time i checked castrol does not make 0w40

 

OEM is 5W30. GC is 0W30.

 

Ya that's what I meant, 0w30, sorry was tired and didn't write it correctly. So if anything happened to my motor and I took it in under warrenty they'd void it due to not using 5w30 or it's be fine?

 

^
just don't say anything about using 0w30.. it's not like they can actually tell unless they go as far as running some kind of oil analysis..

 

Nissan only recommends 5W30, I don't think they could void your warranty for that. But they will probably give you grief and be a PITA.

BTW my dealer could tell I was using 0W30 from just looking at my oil. GC is green so if the tech is very knowledgeable when it comes to cars then he might know.

 

Stupid question but when I told my friend that I'm using 0w30 instead of 5w30 he FREAKED out and told me I'm gonna blow my motor if I keep using it because it is too thin and I'm starving my motor, he also said 5w is too thin also (which sounds weird cause Nissan reccomends it?) idk, he's not telling the truth right?

Oh off topic but inwas reading about the ppl using GC and at idle there
oil gauge reads 5-10psi. Mine reads the same it has since day one, even when I changed to GC...at idle it's at the line in between 0 and 60 (I'm guessing that's 30) that's normal right

sorry for the n00b questions.

 

I'm thinking about using Mobil 1 15W-50 with my built HR engine. any advise? (120F around here)

 

Your friend is stuck in the old days of crappy built motors. BTW ask him if he knows the difference between 0w30, 5w30 and 10w30 and post his answer please.

 

The only thing I've learned is that our electronic oil pressure gauge is garbage and pointless to look at.

 

I asked him and this was his responce


"If your car is supposed to use that oil there's nothing wrong with it, it really depends what the bearing tolerances are on your car, but the different numbers are different thicknesses, so the 0w30 is the thinnest ones, which in turn will give you the lowest oil pressure. I would just use the recommended oil cause there's not much you can gain from using the other oil, many times it'll say in the manual to use the thinner oil if you live in a cold climat e, because the thicker once can never fully warm up, so it stays too thick which could possibly glaze over the bearings, but that very unlikely, and very near impossible especially in California, I just don't recommend thinner oil, since its usually pretty hot around here. And like I said, sometimes the dealer will do tests on the engine to try and find ways where they can refuse a new engine or something under warranty since it costs them so much.

 

He's almost right.

What you need to know is that the first number refers to the way the oil behaves (thickness) when it's cold, and the second number is when the oil is hot. So theoretically a 0W30 should be the same as a 5W30 once they're both up to the same operating temperature. However, for some reason my car's oil pressure gauge reads way differently with 0W30 compared to 5W30.. so something is fishy for sure.. either the oil manufacturers are lying to me (0W30 is Castrol, 5W30 is Mobil1), or my Nissan is retarded, or who knows...

 

I also noticed a difference in oil pressure when I switched from the dyno oil that Nissan was using (previous owner of car) to GC 0w30. Previously on the dyno oil I was idling at around 15-16psi when warm. Now the car idles around 20-25 psi when warm. Strange. My thinking is it may not be the oil, but the oil filter. I'm using a Purolator Pure-One filter as opposed to the made in China Nissan OEM filter that was originally on there.

 

Why would anyone with an engine that has any sort of cvtc want to change oil viscosity? Seriously nissan makes their recommendation for a reason. The intake cam timing on our motor is continuously variable depending on oil pressure/engine speed. It may not make a huge difference but why risk it. I have seen instances where using 15w40 on a car with cvtc (wasn't a Nissan) caused drivability problems. To each his own I guess but there is nothing wrong with 5w30 and it is what nissan Engineers decided would be best for our engines. BTW going with thicker oil increases viscous drag which can cause very slight power loss. why would anyone want that. As for me I use castrol edge 5W30 and change it at 3-4k mile intervals.