Hey all just did my oil change yesterday evening and also replaced the oil filter. I threw in Mobile1 synthetic 10W-30 and a Purolator filter. When trying to find the right filter number the reference book only covered the 2004 models (I am 2005) so that is the one I bought and installed. This filter was physically longer than OEM and I read somewhere that you should only use OEM Nissan filters and heard others say that's bull. Now after the change it seems that my oil pressure, according to the gauge, is running a bit higher than it was previously. Is this a problem?

 

Personally i have never run the stock Nissan filter exept for on the first oil change. I used the Puralator w/ Mobil 1 up until my last oil change when I switched to Amsoil 10W-30 w/ an Amsoil Filter.

 

The higher oil pressure may be due to the thicker oil you used. Factory recommended viscocity is 5W-30. Any reason for the 10W-30?

 

Hey undrgnd, I kinda came to that conclusion after driving the car a few more times. I do notice that when the temp gauge shows that the car is warmed up, the higher viscosity oil isn,t quite at operating temp. The pressure will almost peg out at 120 if I really get on it.
For some reason they were out of 5-30 and the manual says you can run 10W-30 but obviously the lower operating temp goes from -30 for 5W to 0 for 10W.

 

The oil pressure will always be higher now than when you first bought the Z. When I first changed the oil and fired it up, I noticed it was like 70 psi cold. It used to be closer to 30 when cold. I changed the oil and filter four times that night with different blends and filters. M1 5W-30, 0-W30, and 0-W40, along with a Purolator, M1, and Nissan oil filter. It doesn't make one bit of difference. The oil that came with the Z was specifically for the break-in period I believe, and nothing else will- or should- behave that way when cold. Give the Z a minute or two of easy driving before opening it up, I wouldn't push the oil pressure gauge to 120psi when it's cold if I were you. It will eventually heat up and settle into 30psi idle and then you're all good to go.
As far as the filters go, the Nissan filters are just fine. Many people use the filter on their SR20 race motors in the SR cup without any problems. The SR uses the same stock filter as the VQ35. If you want to go aftermarket, stay away from anything that uses a paper anti-drainback valve like Fram. The Mobil1 and K&N filters are the same filter, so whichever you find for less- they are a great filter, but pricey. Check this site out, it is run by a bunch of petroleum engineers and will blow your mind with all the information you never cared to know about oil and filters. www.bobistheoilguy.com
there is a link in there to the oildrop forums. Great info.
Will

 

If you have read other oil filter test reports you know Purolator is one of the biggest manufactures of oil filters. They not only make and sell oil filters in their own name but also make a lot of filters for Motorcraft (Ford), PowerFlo, ProLine, and other companies. Since the Pure One is their top of the line, and they make the Motorcraft they are included in this study.

They are one of the only two bottom bypass filters in this study. A design not approved of by Ford because it allows dirty oil to wash over the dirty side of the filter and gather the dirt settled in the dome end of the filter on the way to the bypass valve. Reportedly water could also collect in the dome end of a bottom bypass design and freeze the bypass closed which could starve the bearings of oil until the filter thaws. The first reason, washing the dirt of the filter seems very important to me. On the other hand who has several ounces of water collect and freeze I their oil filter? That seems far less frequent to me.

The filter does have a lot of "Micronic" media, (213 sq. in) which I assume is a premium type paper. I have no hydrostatic burst information but the shell measures .009" which is on the thin side.

Ranking all filters in one of 3 target market groups, "Good," "Better," or "Best" the Pure One is "Better" group, a cut above the "good" flea market quality for only $6.

http://www.shoclub.com/lubrication-o...n-oilpart5.htm

 

While that site is pretty good, they fail to inform you that not only does the purolator out flow the K&N filter and mobil 1 filter, but it filter's better than the k&n and is cheaper and easier to find than both, In my book this is the way to go, http://www.oilfilterstudy.com/ is another good site which has flow characteristics and independent tests done by the actual people who run the site