Synthetic vs Regular Oil

[EricTheCarGuy]

I’m sure this one will have a few opinions, I look forward to yours.

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[EricTheCarGuy]

[quote=”garageman402″ post=111723]I think most people are thinking of synthetic oil as a “fountain of youth” for their engines. My experience shows it is not, at least in stock, everyday drivers. I ran Redline 0w-30 and Chevron Supreme 5w-30 oils in a 2000 Pontiac Montana 3.4L V6, and a 2008 Buick Enclave 3.5L V6. Analyzed the oil and the wear numbers were identical. I did do a few changes with each oil before sampling to be sure there was no conflicting chemistry.

I also was under the impression I could run a lower viscosity synthetic oil as it would protect better, flow better, disperse heat better, and result in fuel economy gains. The 0w-20 and 5w-20 (not Redline) I tried did not lube the wrist pins adequately and I lost the bottom of a piston. The 3.4L V6 had 158,00 miles, and is notorious for intake gasket failures every 60,000 miles allowing coolant into the crankcase, maybe this added to the engine’s early demise. The analysis comparison was done on the new GM service replacement engine in this vehicle.

The Chevron or Shell 5w-30 or 10w-30 oil you can buy at Costco when it is on coupon special for $27 a case is just as good (for stock engines) as the $137.88 per case Redline 0w-30. For the price, you can change the oil every 1,000 miles, and still be ahead.

In my opinion, the best thing you can do for oil is change it. I think Eric has the same opinion. As a bonus, you are getting all the small particles out that cause engine wear.[/quote]

I agree. The best thing to do is change it on a regular basis with a quality filter and the correct viscosity as called for by the manufacturer. That’s the best insurance for your engine.

[Ronnie]

Hello everyone.
First of all I did not read all 14 pages of this thread.
I just want to share some of my experience working with cars and other machinery.

Synthetic oil is always better from a lubricating point of view.
But there can be instances where the fully synthetic oil can do harm.
As a test i used a fully synthetic oil (I think it was 10w40 expensive well known brand) in a old ford 15M engine.
The 15M an 17M engines can be found in old Saab V4 and Ford Taunus.
The camshaft and lifters in those engines are lubricated trough the oil coming through the rocker shaft and drips down from the shaft and rocker arms. The oil then passes under the intake manifold and drips down to the camshaft and lifters. The synthetic oil don’t “stick” to the parts as a mineral oil does. It was not enough oil flow to keep those parts lubricated enough. The camshaft was almost completely round and the lifters had so much wear that they were concave on the friction area. All other parts i the engine were fine. I can post a image of one of the lifters if anyone are interested.

Another experience I have of the mineral oil sticking better is when you look in a junkyard, the engines with the cam covers taken off the parts don’t start to rust as fast. The synthetic oil have a tendency to slip off so to speak. This is also the reason when you assemble a engine you use a thick mineral oil or a assembly oil specially formulated for assembling engines. If you use a “normal” synthetic oil, thick or thin there is a risk that the parts gets damage before the pump can fill all of the engines oil canals.
But that problem with the cam and lifters wont happen in a modern engine where the oil gets pumped to all places in the engine. When the parts in the engine get enough lubrication you can’t beat synthetic oil.

A example of this I experienced with a fully rebuilt and honed engine, every part new.
When you break in a engine I recommend you using a cheap mineral oil because the synthetic oil gives to good protection so the piston rings don’t wear in as they should. I was in a hurry and poured the fully synthetic oil in, two jugs, both gray with similar labels, I took the wrong one. I discovered this 620 miles later. That engine would never stop smoking and used a lot of oil. The oil escaped trough the piston rings. The only solution to this was new honing of the engine block an new piston rings.
I know of other honing techniques that prevent this, but that’s not what I am trying to share.
For those interested in breaking in engines, this man explains this much better:
“Break-In Secrets”

As for a engine to bee cleaner inside, the synthetic oil does a better job you say ?
This is a myth, almost every oil in modern times have additives to keep contamination trapped in the oil. Another example: I had a Saab engine tuned from 185HP to 300HP, I changed the oil in this engine every 3200 miles or so, Red line, Quaker state Mobil, Valvoline and so on 20w50 15w50 fully synthetic. A friend of mine had a old Volkswagen beetle, he also changed the oil every 3200 miles with mineral oil 10w40. When he opened up his beetle engine an I opened mine after about 75000 miles or so, they where both identical clean looking inside. It doesn’t matter what engine oil you use as long as you change it when you should from a cleaning point of view.

As for wear and following the manufactures recommendations I want to share this.
When the 0w40, 0w30 (and so on) oils where intruded in 1998 or so, almost all manufacturers recommended these synthetic oils. And the service at the professional service workshops use/used this type of oils.
I have opened up identical engines, one only being fed 0w something oil from the service workshop. The other one (mine) only using 15w40, 20w50, 10w50 synthetic. Both engines where tuned the same way and had about 80000 miles on them. Both where Saab 2.3L engines and both where owned by the same owner, the cars where bought with about 18000 miles on them. One in 1998 and the other one in 2002.
The one that used the 15w 20w oil had little or no visible wear on the bearings and other parts. The most wear found on that engine where at the TDC and BDC of the cylinders.
The other one using the 0w oils, all of the bearing where missing the babbit surface the steel in the bearings showed. The lifters had deep groves in them from the camshaft and the springs for the lifters were very worn on the sides.
I haven’t reed up on the 0w oils since, maybe they have solved the problem today, but I never put anything thinner than 10w something or if in a pinch 5w something. As the salesman ones said to me: The difference between the 0w oils and 5w 10w oils are that the 0w oil is just as thin cold as it is hot. So it is identical to the old oils when hot.
This is bullshit. All oils gets thinner when they are hot and that effects how well the oil can keep the surfaces apart in the bearings.
My point is that the manufacturer isn’t always right. There priority lies in low emissions.
Another example is just to look at the oil when changing it, removing the sump plug from a hot engine or a cold one. The 0w oils when hot has the viscosity of water.

These are some of my personal experiences and I don’t claim to be a expert. I’m only trying to share some of my knowledge.
I hope this is of some interest. Feel free to comment.

And thank you EricTheCarGuy for all those interesting and informative videos.
/Ronnie

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