engine oil selection

[nismospek]

Well im finally getting my 240z up and running and I am planning to do

an oil change. I want to stick with a synthetic oil. I use Royal Purple

on my 240sx but I have also heard of people using Mobil 1 synthetic on

the 240z.

I was wondering if there where any other good synthetic oils out there

and what viscosity it should be. I was also wondering about how many quarts

and which type of oil filter (possibly fram). Thanks.

[DatsunZsRule]

aahh this question again :D

You Will obviously get more than one answer here on this topic. I've seen topics like this sometimes turn into arguments everyone gets attached to the brand oil they use.

How many quarts? - 4.5 quarts

what viscosity it should be? - depends on your climate. I use and recommend 10W30. Only time 20W50 should be used is if you live in a place like AZ. where it's 100+ degrees in the shade during summer.

which type of oil filter ? - another one you will get lots of opinions on. Personally I only use genuine Nissan Oil Filter in my Z.

Brand? - Valvoline is my personal favorite.

[red_dog007]

I just used some good old Castrol GTX 10w30 in my 240z. I have heard that Chevron heavy duty 15w40 is some really good stuff. My bro knows a mechanic that uses that stuff in all his rigs and says that is some of the best stuff you can get. Can't remember the exact kind though.

[zed74]

old technology engines generally don't always suit modern synthetic oils.

In Australia (Brisbane) I chose an oil for L series engines in the 20-50w range and no problem (Penrite HPR30). I have friends who race (club sprints/tarmac rallies) with mobil 1 10-40w synthetic and again no problems. My personal conclusion is buy good quality oil & change oil & filter regularly. Mineral/semi-synthetic/full synthetic is purely a matter of personal choice/budget/experience. If you are paying under AUD$30 for 5 litres - spend the extra money.

[nismospek]

lots of good information. I forgot to say I live in San Antonio, Tx. So i will

probably will be going with the higher viscosity.

[Carl Beck]

I run Mobile 1 10-40 because it will reduce engine operating temperatures 10 to 15 degrees here in Florida.

I also run Red Line Water Wetter and water in the radiator - because it will reduce engine operating temperatures 10 to 15 degrees here in Florida.

These two things make the difference in stop and go traffic between seeing the temperature gauge approaching HOT or staying in the middle (normal) in the summer months.

FWIW,

Carl B.

[deadflo]

Carl, I am going to ask around about the water wetter stuff, as I need to flush my radiator for the season anyway. Do you know specifically what it does?

[DeesZ]

This is just my opinion and practice. Some folks will take issue with it because this seems to be an overly sensitive subject, but hey, it works for me, and it's pretty much what the FSM recommends. I have used 10-30 mostly. In the old days Penzoil or Quakerstate were my choice because they were rendered from Pennsylvania crude oil (which has been argued to be one of the best crudes available). Today I don't think either are from that source any longer. I now use Castrol 10-30.

I will say this, going 'back' to 10-30 after you use 20-50 for an extended time may cause excessive burning of the oil (I guess from blow-by). I had that happen back in the '70s. My old store became a Castrol distributor and I was able to get a great deal at cost or promotional courtesy/gift/bribery. 20-50 GTX came on the scene and was a huge hit with everyone, so I switched over at the encouragement (actually bribery) of the Castrol rep.

The stuff was great - no question about it. But in the north-east when winter hit hard the car did not seem to be able to crank as fast as I wished it would and starting before killing the battery became an issue. Mr. Castrol suggested that the heavier oil could be slowing things down a bit so he gave me a case of 10-30 to see if that took care of the problem (he wanted me real happy since I was in the position to recommend his products above those of several competitors). It was the fix that I needed for the sluggish starting in bitter weather issue. But there was the issue of oil consumption after the switch-back. If I'd get on it at all, there would be blue smoke out the back. Switched back to 20-50 & smoke went away. Made me happy that I wasn't facing a major repair. That 20-50 performed flawlessly for about 8 more years until I sold the car. It did leave me more at the mercy of bitter cold weather with the starting issue. I thought about getting a heated dipstick like I had when in Alaska, but a trucker friend of mine suggested a 100W light bulb under the hood beside the block overnight with the hood closed. Worked like a charm for many cold winters even with the 20-50.

My current 240Z doesn't need racing oil; the 10-30 gives me comfort of knowing that I am protected well at start-up with the thinner low-end & adequately with anything I am going to throw at it with the 30 at the high end. Keep in mind that the oils today are superior to those that were commonly available in the '70s when the factory recommended 10-30 for temps ranging from -5 ~ +105degF. As I said right up front; just my opinion and practice, for which I see no compelling reason to change at this time. I could be persuaded to change with some good reasoning..... just haven't found it yet.

[Carl Beck]

Carl, I am going to ask around about the water wetter stuff, as I need to flush my radiator for the season anyway. Do you know specifically what it does?

Red Line's Water Wetter is a surfactant with the necessary anti-corrosives and water pump lubricants found in permanent Summer Coolants/Anti-Freeze.

A surfactant breaks down the surface tension of a liquid and thus allows the molecules of the water to come into closer contact with the metal surfaces over which it is flowing. In turn this allows the water to pick up more heat from the engine, and it allows the water to pass off more heat when in the radiator.

Most major automotive parts stores carry it today..

FWIW,

Carl B.