What oil should i use?

[NissanSupraGTR]

Well i just got a 240sx and i've changed pretty much everything myself , except for the oil (my dad had it done for $30 :/) so i want to upgrade to synthetic asap. thing is, dunno what type i should get, as in 5w30 or 10w30 etc. My car's specs are in my sig, and i live in jersey if that helps. On a related note, is mobil1 the best synthetic?

[slyedog240sx]

how many miles? 5w30 up to maybe 150,000 and 10w30 over that. If you switch to syn. Remember that you need the better filter and yes imo m1 is the best. Also plan on some minor leakage as syn. will leak through seals a little depending on engine wear.

[2056515]

it will most likely leak if u switch to synthetic, and it might not be minor. what kind of oil was it running before?...maybe stick with that.

[gumby74]

Stick with good old fashioned dinosaur oil. Considering the length of your mod sheet, whatever benefits you think you will get, are not gonna happen.I dont think I have ever used synthetic on any engine i have ever rebuilt for street, sport or otherwise. Simply get into the habit of staying on top of maintenance. I religously change my oil every 2 months, or when the color goes from beer to pancake syrup.

[NissanSupraGTR]

Doesn't using syn prevent deposit buildup and the like and last twice as long? Engine has 118k miles. If its gonna leak, i dont want to use it; is the general consensus that it will?

[Rez240]

I recommend using M1 if you want a syn. I use 5w30 changed every 6k w/ a filter change every 3k. First owner started doing this when he purchased the car and I'm now the third owner. The car made it 250,000 w/ no major engine repairs and never leaked.

It is possible though when you switch to a syn it could leak a little. I agree with Gumby you can stick with the regular stuff (and save a ton of money) just make sure and check it once or twice a month and change her out when it goes from beer to syrup.

[gumby74]

And to add to that, once a year usually around Fathers day, I run some motor flush, check plugs, cap, coolant you know the drill. Summer is a 10 month ordeal here in Tejas.

[slyedog240sx]

yes it will leak. I had about 100,000 when i switched. it doesn't get low really but a very small leak is present. When i used regular petroleum no leaks. i change it every 7,000 to 8,000 on m1 ep 5w30 which is 15,000 mile oil so they say. i also use the m1 filter. costs to much but don't want to change back now. stay with regular oil.

[Timeless240]

There was a HUGE 240sx oil thread around here somewhere, or maybe it was on another board. What i got from the oil experts in the thread is that:

1. modern synthetic oil IS SUPERIOR to modern dino oil.

2. To avoid the leaking from the seals (rear main seal in particular) when switching from dino to synthetic on our 240's, we should do 2 special oil changes before going full synthetic. - We should first change to a 50/50 mix of Mobil1 DELVAC (synthetic diesel oil, i used 15w-40) with whatever dino oil weight we previously used and run it for only about a month or two. THEN, next oil change we should change to full Mobil1 DELVAC and run that for a couple of months.

Now you can go to your normal Mobil1 synthetic oil, whatever weight you prefer. The oil experts recommended 0w-40, and that's what i use, and i forget why, but i came to that conclusion years ago based on my engine starting and driving habits, environment, mileage, and octane used.

I did all of this and I don't have any oil leaks. I actually DID have some oil leaks before i started this procedure, and apparently it got rid of it.

[lbrowne]

Use regular oil. Just be frequent and consistent with your oil changes.

5w30 is fine, I use it on my 170k+ mile ka with no leaks.

The key to oil is changing it when you're suppose to.

[NissanSupraGTR]

alright thanks for the advice guys. Looks like im stickin with the normal stuff