why not synthetic

[DaveBonds]

wow the info thats here.....i started the thread and then i had to leave for awhile and come back to a lot of info lol.......this is great.

but to be a pain i have a two new questions:

1. i have seen people add a quart of trans fluid to the oil every other oil change and the logic is that the trans fluid has detergents that will actually clean out the engine of previous neglect ....and i have to admit i did this on my slant six in my dart when i first got the car ......when i got the the oil in it from the previous was kinda sludgy ...and the filter on it was ancient ......it was k-mart brand.....like how old is that........i did notice increased leaking after that ....so i replaced the oil pan and valve cover gaskets and been running now over a year and i have put around 12,000 miles with no other problems.

whats you take on trans fluid in the oil. is it a good idea.

2. would synthetic call for a different oil change interval than dino?
on newer cars i have been in the habit of letting it go 5000 for oil changes ....and usually i look at the oil and it really is pretty clean and the engines are in great shape.......would the dino really break down faster and not make 5000......assuming the engine is in good shape as i understand a worn engine will dirty any oil with blowby and in-efficiency.

1. - Transmission fluid is a modified oil, designed to act as a hydraulic fluid and as a wet clutch fluid. It has friction modifiers in it for the clutches. This is why people prefer to change their power steering hydraulic system to a more suitable hydraulic oil that does not have a friction modifier in it, like power steering fluid.

The friction modifiers actually aid in metal adhesion under friction pressures, so I could imagine that it would bind with contaminants and do what you are talking about.

There are better things on the market that are designed to clean engines, both on the oil and combustion side, to decarbon. I would suggest using those, instead of something that hasn't been lab tested with proven results. It may not hurt the engine when used as a changing detergent, but then again, that is guess work. The idea is based on it's viscosity and friction modifiers, but without seeing how it reacts to engine temp, I don't know what it does on a molecular level to the metal surfaces, so I wouldn't suggest it.

2. - Oil change interval is directly related to the application of engine and oil type. Synthetic oil is more stable in wear and viscosity properties between cold and hot temp. Oil viscosity is rated at cold and hot temps, cold in viscosity testing is @ 72°F, hot is @ 212°F... So when the engine oil temp is below 72°, the viscosity can increase drastically.

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Oil running temps change with use. Heavy loads increase oil temp. The usage of it's additives and increase of carbon pollutants also increase with the temp.

How you drive the car or use the engine changes how often you should change your oil.

Newer engines, because of the higher requirements of thinner oils and tighter clearances, fuel injection and having more detergents, have fewer pollutants from those things. This means that the oil has fewer additives that are used up, during the usage cycle, as well as running cleaner within it's use cycle, so it can inherently have a longer use cycle.

These older engines still require a 3000 mile change (or less if you beat the snot out of your engine) because of the components needing those additives that are used up within that frame of use cycle that new engines are simply void of, that have been engineered out of.

I still prefer a 3000 mile change in cold weather on new engines, even with synthetics, because the oil molecules are put through more extreme temp inversion, which changes it's elasticity and uniformity.

 

[805moparkid]

I guess my point was that newer technology is at least worth a look and shouldn't be ignored just because "it ain't the good old stuff".
If people knew what it actually cost in other resources to produce a gallon of corn fuel they would be surprised and never use that crap.

e85 and pure eth have thier place, but not in street fuel... and i could only wish it would go away...

 

[1970Duster]

I use nothing but syn in all my vehicles. Rear end, tranny, engine that all get it. As far as interval, you pick. In my dd it says clear as day in the owners manual, 10,000 miles or 10 months whichever occurs first.

 

[UOP]

Here's the deal with grade 3 base stocks. Yes, grade 3 stocks are made from crude oil, but have been hydrocracked (vaporized by extreme heat and pressure to isolate a particular molecule, then bonded with hydrogen to stabilize it) to form a completely man-made product. This molecule did not exist in the original crude form, hence why it is classified as synthetic.


The primary benefits to this process are:

A) The process isolates only the best molecules for lubrication.

B) The introduction of hydrogen in the process neutralizes the oil making it much less likely to oxidize (where sludge comes from) and allows for the much higher drain intervals we can now enjoy.


These are also reasons why grade 3 oils are superior to conventional oils. Another benfit of synthetic vs conventional oil is the way the viscosity modifiers are used. Take the same grade oil, 10w-40, as an example. A conventional oil will start out as a 10w and will have modifiers added to make the oil 40w at operating temp. The problem with this is that if you run the oil too long it could loss the modifiers that make the oil a 40w, and before you know it you're running a 10w-20.

Synthetic oils are the opposite, starting out as a 40w and modified to act like a 10w while cold. This is one of the reasons synthetics are much more stable at higher than normal engine temps. Interestingly, synthetics flow much better when cold. Try freezing a quart each of conventional and synthetic overnight and poor them out the next morning. Imo, this alone should be a reason for those who live in extremely cold climates to switch.

All that said, almost all major brand oils (Castrol, Pennzoil, Valvoline, Shell, etc) use grade 3 stocks. For years Mobil1 was advertised as using only grade 4 PAO stocks, but are now blended with grade 3 to meet performance/cost criteria. Currently the only brand I know of that uses 100% grade 4 base stocks is AMSOIL, but they now offer "introductory" oils made with grade 3 stocks. I'm sure there are others, I just can't think of them right now.

 

[DaveBonds]

They do put the grade 3 through extreme pressures, creating a better uniformity of the crude base stocks.

Redline, if I'm not mistaken, is an Ester base stock, which is awesome. Royal Purple is PAO, I think. I know that Penn Grade 1 is crude and PAO blend.

Mobil 1 is good oil, but just like all other modern oils, is set up for new engine designs and have insufficient levels of additives for flat tappet stuff, including phosphates and zinc as well as other metals used.

That in itself isn't a bad gig, because you can add them in, if you're careful about which ZDDP additive you use, but the parts per million of ZDDP in the additive oil used should be known. Too much zinc is terrible on soft, tri-metal bearings and also rusts iron in higher amounts. So yeah, you can do it, but you should have a lab report from somewhere online that is current, so you know how much you are putting in 1400-1500 of Zinc and Phosphate measured in parts per million is a good range for flat tappet.

The problem I have, which isn't isolated to Mobil 1, is that they put way too much detergent in new oils for older engines and that number has increased significantly over the past couple of years.

The only oils that do not have higher amounts of detergents are race oils, designed for high performance applications, where they know that people are running components that need the additives to stick, but that swings the pendulum in the other direction, if you're running an old engine in something that is not going to be torn down to clean, after racing it for several seasons; there aren't enough detergents to keep it clean for the street.

It's a balancing act.

This really has nothing to do with conventional oil versus synthetic, as you outlined. Synthetic oils and grade 3 crude base stocks are far superior to Grade 1 and 2 crude base stock conventional oils for the stability in viscosity and anti-wear properties, between hot and cold running temps. No doubt.

The trouble I had, that lead me to run Penn Grade 1, was that I couldn't find another full synthetic that had the right amount of detergent, coupled with the right amount of zinc and phosphate, to run a flat tappet on the street that would stay together and stay clean for 100K+ after a rebuild.

I'm sure I could formulate something myself if I had the reports of shelf additive packs, which are easy to obtain, but finding an oil with the right amount of detergent is what I've run into a wall with, outside of Penn Grade.

 

[69DARTS]

use this

 

[Jarlaxle]

Oil is oil. There, I said it: oil is oil. Synthetics are better...but it just doesn't matter, because regular oil is good enough. My Jeep gets 5W-30 QS Defy in the winter, and whatever 15W-40 I can get the best price on (usually Wal-Mart's house brand) in the summer.

For flat-tappet cams, diesel-rated oils and Quaker State's "Defy" have additional ZDDP.

 

[Abodybomber]

Dave bonds: "
The trouble I had, that lead me to run Penn Grade 1, was that I couldn't find another full synthetic that had the right amount of detergent, coupled with the right amount of zinc and phosphate, to run a flat tappet on the street that would stay together and stay clean for 100K+ after a rebuild.
I would.be a betting man,they used the old Kendall's formulations here.

 

[PanGasket]

"
The trouble I had, that lead me to run Penn Grade 1, was that I couldn't find another full synthetic that had the right amount of detergent, coupled with the right amount of zinc and phosphate, to run a flat tappet on the street that would stay together and stay clean for 100K+ after a rebuild.

I would.be a betting man,they used the old Kendall's formulations here.

Same refineries and all, but they supposedly tweaked the formula some

 

[moparmat2000]

in another thread I caught where someone said to not run synthetic oil .......that caught my attention because I have heard that before from other people.

this also caught my attention because I was told auto school that synthetic oil is a good thing.

and the reason is: its basically lab created and has more consistent microscopic ball bearings which the essence of oil itself .....so because its more consistent it has different break down patterns that conventional which is a good thing regarding engine wear.

also there are chemicals added to keep it from breaking down and keep the viscosity more consistent for a longer time as compared to conventional.

so my question is: do I have the wrong info about synthetic oil and is synthetic oil a bad thing or good?

Hi Rani

Im sure you heard a bunch of answers, comments, theorys etc in this thread, so i decided to throw my 2 cents into the ring as well.

My school of thought on this subject is both are good, but synthetic is better for reduced wear. I would never recommend synthetics in a freshly built engine however because they are too slippery. You can actually have too much of a good thing.

When you have a freshly rebuilt engine you want to establish a bit of a wear pattern on the parts, and allow the piston rings to seat so you dont have blow by. After this initial wear pattern and ring seating process is done i'd say at about 5,000 miles id switch to synthetic and never look back.

I have a friend who had 375,000 miles on an 89 chevy pickup at my work. Id say he got his moneys worth out of it by now, always ran synthetic in it after engine break in was complete. Body is clean, truck looks nice, so he decided to have the tranny overhauled, and bought a new crate long block for it. The original 350 will be getting built up for his econo rail dragster. He tore down this old 350 to get it ready for machining, the bores looked great, the bearings looked almost like brand new. He probably could have run it another 100,000 miles with no problems. The point is synthetics severely reduce internal engine wear. They may cost more to use but the trade off is longer engine life.

This is my .02
Matt