DARTHSWAN

Okay,

I have made the decision to go with it. I do have a couple of questions for you all. Was there anything special you had to do in advance? I've seen a wide range of people saying when to change their oil. How often should you change it? Opinions on the best would be greatly appreciated also.

K

marc98se5

I have been using Castrol Syntec in both my Pathfinder and Maxima. I change both every 5,000 miles or about there.
I also use a Nissan Oil filter in both.
Nothing special to do, just change normally. I think some people even still change every 3,000 or 3 months.

ny96max

I use Penzoil Synthetic oil. Before that i was using regular Penzoil motor oil. When i spoke to my mechanic he told me that you can easily put 6k miles on synthetic, even though they say its good for 9k. I change mine at 6k everytime. It will take you about 3-4 oil changes initially to circulate out all of the original oil from the block, and for only synthetic oil to come out the motor.
I go to Jiffy Lube by my house, cause i know the guy working there and i get hooked up with synthetic for the price of regular . I also have them do my tranny fluid every other oil change.

hope this helps,

Ant

DFWmax

i have read and have heard many people mention it -- when you switch to synthetic oil, the firts few times you run it, it may get dirty quicker. this is supposed to be that the synthetic oil is dissolving and "cleaning" the gunk that was left behind by the previous use of the regular oil. as a result, you may notice that the synthetic oil is getting dirty more quickly during the first few synthetic oil changes.

just a fyi, i have not personally noticed that; i did a switch to synthetic on my 1990 maxima after it had about 60,000 miles but i didnt notice the above description, and my new maxima (1999) has been on synthetic since 1300 miles.

i change my oil (im using redline 5w30) every 7500 miles. but that is also with my driving pattern -- virtually all hi-way miles, and i dont race, just a few spirited drives here and there....

dfwmax

Curt Deiner

iTrader: (1)

I decided to go synthetic after reading "Rx for Long Engine Life" by Curt Scott. Why would you not! I'm using 5w30 Mobil 1. Manual says 5w30 is good to 104 deg, so I figured no problem here in Mpls. Then it got up to 94 deg yesterday! Also using Nissan filter. A quality part for $5.50 from my local dealer, like the seal gasket. I'm more of a time than mileage driver, and plan to change at 6 mo. Should be about 5-6K miles. Hey don't skimp, buy a new drain plug gasket. Took a breaker bar too get my plug loose. Last change must not have done. The gasket was smashed onto the plug so hard, took my jeweler's screw driver to find the edge and pry up enough to grab with pliers and unscrew it off. Screw the plug onto the new copper gasket from the formed side of the gasket. Seemed to work for me. Torque to 30-40 Nm. No tool used for my filter. Came off by hand, put back on by hand. I think I'm going with synthetic in 5spd tranny too. Sounds especially good come winter for ease of shifting. BTW the maxima oil change is easy!

DARTHSWAN

Thanks for all the initial information. I think I'm going to go to Walmart and have them do it. They use Castrol Syntec down here. When you all put the oil in, what type of difference did you notice?

K

Curt Deiner

iTrader: (1)

Only been about a week. And it's gotten quite a bit warmer here. But it may be quieter, smoother, and revs faster (what I'd like to think) hard to say yet. It does seem to have less of that rattle like no oil for a half second at start up. I think that's more a function of a good anti-drain back valve in the oil filter.

humaras

I switched over to syntethic mobil 1 last fall before the winter came--that was Oct 1st of 2000. I changed my oil this spring on May 9th...so that was about 8 months or so...I drove about 3000 miles for the time (NYC...not too much mileage). But I too noticed the oil getting darker a lot quicker the first time--probably after 2 weeks, the oil was pretty dark. However, the color of oil isn't any type of indicator of the "quality/life" of the oil.
I have the synthetic mobil 1 in and I don't plan to change the oil probably until december or when I have hit 5-7K --since I do drive more in the summer.
In any case, I switched because I am just lazy of changing oil--hate bringing the car in etc...and since most of my trips are very short distance, i figured the extra protection would be good.
Oh yes, I have also noticed the shifting to be more fluid...could be just psychological though.

goldmax

Did you know that Castrol is not a pure synthetic? One of the big car magazines featured an article where they said Castrol was stretching the meaning of "synthetic" and their brand was really a mix. I'd use Mobile 1 or one of the others. It's kinda disappointing since I have used regular Castrol for years and always thought lots of it. BTW...Walmart had a great deal on Mobil 1 last time I was there...$18 for 5 quarts (all in one jug)in the automotive section.

DARTHSWAN

That is very disappointing to here. I guess I will have to look into others. D'oh. I'm going to go to walmart and check it out. Hey, I do have another question. Is there a special filter for synthetic oil, or is it the same?

K

brubenstein

From a petroleum engineer:

What is "Synthetic" Motor Oil? texasoil
(53/M/Houston) 9/15/00 7:48 pm
Here is the REAL technical information.

Mobil 1 is formulated with what are called Poly-alpha-olefins (PAO's). These molecules look like a zipper or the wire in a chain link fence, with a single unsaturated bond on the end (the 'alpha-olefin). These molecules are pretty good for use in lube oils because they hold their viscosity better with temperatures than 'conventional' lube oil molecules. They are not perfect however. they are not very good solvents for the additives and combustion byproducts in an engine, so the detergent and dispersant additives have to be 'better' than in 'conventional' lube oils. Also, some co-solvent conventional base oil has to be included to keep the additives in solution.

A refining process developed a few years ago and first used by Shell Oil 'isomerizes' paraffin wax so that the isomerized molecules look and behave almost exactly like the PAO molecules- but without the terminal double bond.

These are very different approaches to making essentially the same 'synthetic' molecules. PAO's are made by connecting a whole bunch of ethylene molecules (the poly), while isomerization starts with natural molecule and rearranges it.

Now interestingly, petroleum waxes are often 'cracked' or split up into the samll ethylene molecules that are then polymerized back togetherinto PAO's.!!. Now which way do you think is more costly? Tearing up molecules and then glueing them back together, or rearranging ones nature has already made?

By the way, if petroleum wax, which is mostly straight chain or 'normal' paraffins did not freeze solid at such high temperatures (130F or so) it makes an outstanding lubricant base oil. 'Isomerizing' rearranges some of the 'normal' portion of the wax molecule into 'iso' paraffins-basically adding a few bends and pieces or wire to the main piece.

The Courts found that since neither of these molecules were 'natural' and both are 'synthetic', actually do look almost identical, and behave essentially the same in lube oil, that Castrol (and others) could call oils blended with either as "Synthetic."

ionicmax

iTrader: (30)

When I bought my car it had 25000 miles on it, so what I did before I switched to synthetic was that I changed my oil (with normal oil) and only used it for a week, after that I drained it and put the synthetic stuff in. I did this so the engine would be a little more cleaner before I would put the synthetic oil in.

I use Royal Purple synthetic motor oil, and I would recommend it to anybody I know, when I do my oil changes at 6000 miles the oil looks very clean, so I'm happy with the results.

Good luck!

DARTHSWAN

I'll have to keep that in mind.