Spend the five bucks and put a pure one filter on. The guys at Nissan motorsports say that's almost a necessity on an l-series motor. My opinion on oil (for what it's worth) is that castrol syntec blend is the best. Also I ran my motor out of oil one night out in the boonies with no civlization for to be seen, I truly believe that it still ticks today is because it had dura-lube in it. Not to sound like an infomercial or anything but that stuff saved my butt, and I won't let my car go without it!
Here is a slightly different opinion. As far as oil goes I strayed once from Penzoil GT and used Castrol GTX(it was on sale). That was on a fresh motor during it's break in. I watched the oil preassure in horror as it slowly dove over the first hour of my motors life. I then drained what to me and my freinds looked like water(it was oil) from my motor and promptly put in Penzoil and the oil preasure shot right back up. As for additives, I read a good article at the datsun car home page( leap from this sight) and the most interesting statement that I recall was that when PTFE additives were invented and were starting to be used on internal combustion engines the inventors published a disclaimer saying that this oil was in no way good for such an engine.Research it and use your own discretion.
I will agree on castrol syntec blend, it shows me the best oil pressure (20W50). In the winter though since here we ger -30's I am forced to use mobil 1 0W30 and I have to say, with minus temperatures it wills warmed up in 30 seconds......now the tranny is another story !!!
As far a slick 50 stay away from it due to the PTFE, also stay away from any oil/engine treatment that say "shake well" before using.
Dura lube i used......Didn't feel any difference......but I am sure it is better than the slick 50...that is because slick 50 has solid particles and can clogg your oil filter.
Consumer Reports tested different motoro oil and additives. The installed a bunch of identically rebuilt engines in NY city cabs (a nasty environment for engines, you have to agree) and ran different oils and additives. They even put in the older mechanical valves that wear faster. They then measured for wear on the engine parts(which is what oil is supposed to prevent after all)
Their conclusion: There were NO measurable difference between the major oil brands. Synthetics did not protect any better than regular oils. Also the additives had no measurable affect.
They also tested changing the oil and filter more often than recommended. Once again, no measurable difference.
Their recommendation. Use any oil that is ASME certified.
Save your money, don't believe the BS you hear in oil commercials. believe the test results.
Patrick is right! We tried the oil additives test drain the engine of all the oil and we did not understand why it kept running until we removed the oil filter did we figure it out. As soon as we took off the filter and ran for cover because of all the hot oil spray the motor locked up solid! what we forgot was the bypass in the block kept enough oil in circulation to keep the motor running. Moral of the story use a good quaility oil with the correct viscosity and change it every 3000-5000 miles.