What synthetic oil brand is best?

[nfury8]

As I mentioned before, the molecular size on synthetics is much smaller, and more uniform.
So it can squeeze through tight spaces (rings and seals) that a dino oil couldn't.
This is why a synthetic might leak when a dino might not and why a synthetic might
burn more over a dino oil.

The smaller and more uniform size also greatly reduces traction coefficient.
Think of the molecules as ball bearings. Perfectly round, smaller and same sized balls
will roll smoother, and distribute the load across a larger surface area. The larger,
less regular shaped molecules in dino oil would be like using randomly shaped
and sized balls in comparison.

The smaller molecular size also means the molecules pack in tighter to each other
and surfaces, which then also transfers heat better.

A quick search turned up a decent article.
http://www.machinerylubrication.com/Rea ... ional-oils

[Russ]

That's a good website. I've bookmarked it for future reading.

I'm not debating the superiority of synthetics over mineral or other oils as far as the molecular make-up, I'm just saying that for most of us I don't see the need to spend the extra money. What is it really worth in real world applications that the molecules are more uniform than conventional oils? When I read about the superiority of synthetic oil It almost makes it sound ominous to continue using the SAE30W Pep Boy's oil that I've used for years. They make it sound like my engine is going to grind itself to bits if I don't switch to synthetic oil immediately. But, I put over 200K on an Aspen with /6 and it was still in great condition. My 87 Diplomat with LA318 had 170K when I sold it and the engine performed like new, with no oil usage. I know that it went well over 200K before I lost track of it. My current vehicles have 123K and 154K and both engines are like new and have never had a drop of synthetic oir in them. I had a 69 Chevy truck that the previous owner had seen the speedometer turn over twice and it was showing 67K when I got it, and again, never had any synthetic oil in it. In all fairness it did have a burnt valve when I got it but I don't think that was from lack of lubrication. My best friend moved recently and his 2000 Town and Country van with a Raised roof wouldn't fit in the new garage so he traded it on a new Dodge. It had 254K amd the engine sounded like new, again, with never any synthetic oil in it. My brother sold his 87 Cherokee a while back with over 200K and still performing like new, no synthetic oil ever. These are instances that I know are absolutely true.

The article hints at more power due to reduced friction. I'd be interested to see a dyno comparison. If there's any power gains I'll bet it wouldn't be enough to feel in "the seat of your pants" every day driving.

It's too bad that there's not some positive, definitive way to prove the benefits of one oil over another, or the benefits of a certain oil change frequency over another, but there's no way to do it. For every person who changes his oil every couple of thousand miles there's another person who never changes his, with no apparent differences in the longevity or performance of the engines.

This is one of those things that we all are never going to agree on.

[nfury8]

I like the synthetics in the older vehicles that don't get driven as much because it will not
acidify with age the same way dino oils do. The old 3000 miles or 3 months doesn't apply.
I just have to worry about mileage. So on my Fury and Crew, I might only change the oil
once a year! That is a cost savings!

I believe it was Valvoline a couple years ago had a display and mobile dyno at the Good Guys
show here. They had a Mustang they filled with dino oil and ran it on the dyno. Then they
drained it and ran again with their Power Synthetic whatever oil. As I recall, I think they
were getting 5-8 more horsepower with the synthetic. Impressive that they could prove a
difference, but not enough on that merit alone to justify the added cost for me. Pretty rare
occasion for me to get a vehicle up into those RPM levels they were using on the dyno!

Agreed that motors can run long periods on dino oil, they have for years. But I believe that
it is conceivable that a good synthetic could make a 150,000 mile engine a 200,000 mile
engine or a 200,000 mile engine into a 300,000 mile engine.

A good case would be the Dodge 2.7 liter engine. They were originally designed with a oil
passage that was too narrow. If the oil wasn't changed every 3,000 that passage would
cook the oil and sludge up, causing failure in some engines in as little as 20,000 miles!
We have a 2.7 in our Intrepid and have faithfully changed the dino oil every 3,000 on the
nose and run a crank case flush once a year. It is still clipping along just fine at over
130,000 miles. I did some research when we bought the car and knew about the oil issue.
Synthetics were recommended also, because they handle the heat better. I tried a synthetic
a few years later and it leaked like mad!

Just a little fun math here with my Intrepid because I happen to have an Advance Parts flyer
next to me. Assuming I went 3000 miles on dino and 5000 miles on synthetic.
130,000 miles would be 43 dino oil changes and 26 synthetic. Advance is running 5 quarts
of conventional Valvoline and a Purolater filter for $20. They also have 5 quarts of Synthetic
Valvoline and a K&N filter for $27. And finally 5 quarts of Mobile1 and Mobile1 filter for $30
43 changes at $20 = $860.
26 changes at $27 = $702.
26 changes at $30 = $780.

So assuming you could get some extra miles per change, the synthetic would be cheaper over the
life of the vehicle. Take it out to 200,000 miles and the $20 Valvoline would be $1320, the $27
Valvoline would be $1080, and the $30 Mobile1 would $1200.
OR the synthetic Valvoline would break even at 4000 mile changes, and the Mobile1 would be
about 4500 miles per change, verses 3000 miles on dino oil.

I know there are holes that can be shot in this, but it is some interesting math.

[nfury8]

I just noticed the same flier has Mobile1 Extended Performance for $33 for 5 quarts and a filter.
They guarantee the Extended Performance to go 15,000 miles. Re work the math with that
and 200,000 miles and you get 13 changes at $33, for $429!! Even if you just went 10,000 miles,
that would be 20 changes and $600!

[demulsion]

My folks ran our /6 Dart up to 232k with very infrequent oil changes, with the cheapest oil and filters you could find. By the end it was burning about a quart every thousand miles or so. I rebuilt the motor, and broke it in on dino oil. I changed it after break in, and again at around 2k. Even running Valvoline dino oil, and a good filter, the oil was black. I then poured in Valvoline full synthetic, because I was leaving on a 6,000 mile road trip, and didn't want to have to change my oil half way through... It was over 3k before the synthetic oil changed color enough that I could see where it was on the dipstick. It looks like I'll burn a quart of oil every 10k now. I'm not arguing one way or another here, just sharing my experience in the matter.