Conventional v.s. Synthetic oil?

[stuart]

Which do you use? So far my best/longest oil pressure results from conventional 20W50 with some Lucas Oil Stabilizer added. I've been advised that synthetic oil won't break down like conventional and therefore should keep my O.P. up longer. Whaddya think ya'll?

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Muchas Garcias, Stuart

<LI> 88 Grand Wagoneer 60K mi
<LI> Stock except...
<LI> Kenwood CD and speakers
<LI> Dupont Cherry Red Pearl paint
<LI> View my baby (http://albums.photopoint.com/j/ViewPhoto?u=1340994&a=10041302&p=33310327)

[ChrisCollege]

I prefer to spend less on the oil and change it more often. I don't have a lot of experience yet with my 88GW but my 93YJ has 120K on it changing the oil with Castrol and using a good fram filter every 3,000 and my presure is as high today as when I bought it new. Just an opinion. I am sure their are applications were expensive synthetic makes sense

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88 GW
93 YJ

[WillyPete]

i use 20w50 castrol GTS and change the oil and filter every 3 months.

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"Sugar Magnolia" '86 Grand Wagoneer 235/75R15 Wrangler AT/Rs, np229 x-case, bone stock otherwise

[88gwag]

i have no direct experience with synthetic oil. this is a subject that gets kicked around ad nauseum on the bmw e-28 bb i hang at.if i got the facts straight, synthetic oil tends to remove sludge and crud that plugs up leaks and takes up clearances in high mileage motors. i come down on the side using dinosaur oil and changing it every 3k miles.

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andyd

[YaZahX]

Currently I am using Mobil 1 10w-30...during the winter I plan to switch to 5w-30

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John Z.
My 82 Larado (http://www.virtue.nu/yazahx/jeep1.htm)
YaZahX@aol.com
"Yes that is a Real Jeep, yes the Jeep is older than me."
1982 Cherokee Larado
Edelbrock cam
Edelbrock intake manifold
Holley Projection
31” BFGoodrich

[Snakeyes_Tx]

The previously mentioned 58 Impala that my dad and I built a long time ago... we put over 200k miles on it and when we pulled that motor apart, it looked almost brand new inside there still. It's worth its weight in gold depending on how you drive it, how consistant you use it, and how much you're willing to spend! http://www.ifsja.org/ubb/smile.gif



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Snakeyes_Tx
86 J-20 "The Rusty Dinosaur"
360/727/208/44HD/60 &lt;- 2nd of all of them.
"If you don't know what the numbers mean, you don't need to be here!"

[millerlo]

I was told not to use synthetics in older vehicles because some of those deposits you don't want loosened. Also the lifters must inflate properly. 3,000 with Castol 10w30 winter and 10w40 summer. I seem to run too high a pressure with 20w50 even though the temp gets up there here in Georgia.
Mike

[UnkleMunky]

Though I'm not expert on oils, either dino or synthetic, from all I've read, there are the issues involved noted above, and there's another one that I don't hear mentioned often.

Apparently synthetics are made to have a molecular structure in a smaller, more uniform size. Dinos have a varied molecular structure, plus with the detergents and stuff thrown in, you have a variety of molecular structures moving about. One way this made sense to me is to put a bunch of marbles the SAME size in a container and try to "roll" them over each other..."pushing" them in a sense. Then, do the same with marbles from large to small and everything in between(varied size, in otherwords). What you'll get is a "far" less friction(that's the key here) in a uniform molecular structure setting. Have all different sizes and you have "some" moving regularly, larger ones clogging off the sides, and generally more friction and non-uniform movement of the marbles. Go back to the oil issue and you'll see that it's likely to play out in the pressures exerted on the oils too. The more uniform, the better things flow, and the more ALL molecules move about. Putting less strain on "some" and equalizing it more.

PLUS....with the molecular structures supposedly "smaller" in synthetics than in dinos, you are likely to see more "seepage" if there are already leaks. You WILL see leaks even in a dino usage if you have any, but that's due to the "smaller" molecules probably eeking their way out. With larger molecules in the dino as well, it will be more likely to "clog" small holes and maybe "mask" potential leak problems to some extent, though they are likely still there!

Using synthetics apparently "does" clean things out, and probably cleanses some of those "clogs" as well as allows the smaller, more uniform molecules to seep out more noticeably. So, it's not REALLY that you have a greater problem, but changing the way things are done in the engine will cause different results.

Also, contrary to what many of the synthetic makers want you to believe you STILL need to change your oil regularly. Even "if" synthetics themselves don't breakdown, your engine deposits debris from the firing process into your oil, and this will happen with ANY oil usage, and in turn deteriorates the oil more whether you like it or not. So, though you might be able to go somewhat longer with synthetics between changes, it is STILL a good habit to change the oil regularly....dino OR synthetic!

BTW....I have heard of other methods, especially on getting a used vehicle. Use a good quality dino, but change it every 1000 miles until the oil runs cleaner, and then up to 3000 miles for regular changes. OR...maybe use 1 quart of synthetic to 4 or 5 dinos with your oil change to do a lighter duty clean out.

If you have a "new" engine and run synthetics from day 1, keep it up. If, like most of us, you have inherited a vehicle that's run dino for 100k+ miles, you might want to be conservative in your approach. Good, regular changes, regardless of "type" are a good habit(one I'm moving more toward myself!).

I have nothing against synthetics, and would actually "like" to use them whole hog, but I have to weigh in the previous treatment of the engine(s) too. I've heard you can actually see greater difference for mpg by running full synthetics in your axles, diffs, tranny(if manual), t-case(if gear), than by using synthetics in your engine. If you consider synthetics in the oil, think about your gears too! http://www.ifsja.org/ubb/smile.gif Anyway....there's a little more....again, I'm no expert, but it's a little of what I've learned by looking around....hopefully, I'll keep learning....

Take care....

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Michael(UnkleMunky)
'78 J10: 258, 4 speed, longbed, topper
'76 J10: Honcho, 360, TH400/QT
'89 Plymouth Reliant(PluggerMobile)
J-Pages(some of my auto pages) (http://www.eskie.net/superior/j-pages/index.htm)
unklemunky@eskie.net

[RustyJeep]

Where I work, we do a lot of oil changes with Mobil 1(we are a Mobil Station), and the milage interval we put on peoples stickers is 5000 miles between changes. I also use it in everything I drive. Yes it might find leaks in your engine, but they were just going to happen anyways. Better to get em fixed then, than later. Besides, I can't run out of things to do to my engines. If I didn't have leaks to fix, then I would have to move to more drastic things like pulling the engine out of the J-10.

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RustyJeep
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Project "P.O.S."
'82 J-10 258 4 Speed
Bone Stock...For Now
w/"Custom Air Vents"
Plaguing the Vehicle
Can anyone say "Fred Flintstone Mobile" here?

[Snakeyes_Tx]

One more thing to add, I forgot to mention... it is *not* recommended on engines with over 50,000 miles on them. From what I remember, it'll bond to the gunky old oil and clog things up even worse. I'm sure there's other reasons, but the heavy-line guys at the shop say it'd be throwing money away. If you have a freshly rebuilt or new motor, then you break it in with regular dino oil. After the break-in, full synthetic is a big plus! I've been running Mobil 1 10W30 in mine since the 3000 mile mark on my motor. I still change the oil every 3,000 anyway. After looking at the motor we pulled out of the 58, I'm sold. I pulled a 350 out of a 91 Chebby that ran regular oil with about the same amount of miles my 58 had (about 230k) and all I can say to describe what I saw when I pulled the intake and valve covers off is... TAR.. it looked like tar was poured over the entire motor... real nasty.. and his was a computer controlled Fuelly block too! YUCK! http://www.ifsja.org/ubb/biggrin.gif



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Snakeyes_Tx
86 J-20 "The Rusty Dinosaur"
360/727/208/44HD/60 &lt;- 2nd of all of them.
"If you don't know what the numbers mean, you don't need to be here!"

[SpruceMoose]

once i got all the leaks fixed (it was leaking a quart of 20w50 per day!) i flushed the engine and am now running amzoil 20w50 year-round. i change the oil each year (15k miles) and the filter every 6 months. so far so good, still no leaks. there, thats about 2 cents worth.

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88 Grand Wagoneer
"Spruce Moose"
http://www.FSJtheMoose.homestead.com/files/small_jeep_in_woods_1_cropped.gif
AMC 360, DANA 44 F/R 2.72, TF 727, NP 229
Jacobs Pro-Street Ignition, Edelbrock 4bbl Intake with Holley 2bbl Analog Pro-Jection
Flowmaster 2.5" 50 Series Delta muffler and tubing
Amzoil foam air filter, Amzoil fluids all around
30x9.5 BFG AT
HF,VHF,UHF ham rigs and too many antennas (not)
8-Ball shift knob from college (1975)
Hella aux. driving lights

Next: 3" Rough Country 4-spring lift, Killer32 Bumpers and nerfs, 31 or 32" A/Ts

Mileage? We don't need no stinkin' mileage!

[jeepbob]

If you decide to run the artifical stuff, be prepared to LOSE oil pressure. I really have to wonder with the high rate of flow that it has, how well it will protect a motor that is worked hard. Mercedes does extensive oil testing and reccomends several brands of oil, and NO synthetic is on the list for my 5 cyl turbo diesel.