The Advantage Of Synthetic Oil

[toobroketoretire]

Up until this last summer I had been using Valvoline 10W30 conventional oil but when I found I could buy full synthetic Parts Master 10W30 for almost the same cost I made the switch. When I got home with my new oil I ran a test using a small quantity of conventional oil and the new synthetic oil. I put an old 12" aluminum skillet on my stove and put a cap full of each oil on opposite sides of the skillet and turned the burner on HIGH. After several minutes the conventional oil began smoking but the synthetic didn't smoke at all. After about 10 minutes smoke was billowing off the conventional oil but the synthetic still wasn't smoking. After about 15 minutes the conventional oil was turning to ash but the synthetic was barely smoking so I found the synthetic oil can resist heat a LOT better. After I put the synthetic in my 454" engine I noticed it stayed clear for a very long time which indicates the synthetic oil wasn't getting coked from the heat of combustion like the conventional oil always did. So I'm hooked and will run synthetic oil from now on.

 

[Vettehead Mikey]

Beware that an engine will have overheated and seized solid long before even the cheapest regular oil gets anywhere near it's smoke/coking point. The extra headroom provided by synthetics is of no benefit.

Flame suit on, fire away.

 

[toobroketoretire]

Beware that an engine will have overheated and seized solid long before even the cheapest regular oil gets anywhere near it's smoke/coking point. The extra headroom provided by synthetics is of no benefit.

Flame suit on, fire away.

The thin film of oil left on the cylinder walls usually gets burned during the brief combustion process and turns to coke which then makes it's way past the rings (wearing them and the cylinder walls) and into the oil pan where it remains until the oil is replaced. After I made the change to synthetic I immediately noticed the oil remained almost clear for a very long time which tells me it's not getting burned during the combustion process. I change oil every 5000 miles and with the conventional oil it was pretty black at oil change time whereas the synthetic oil is only a light brown color.

 

[Tuna]

For me, the advantage of synthetic oil is the life of the oil. It doesn't need to be changed as often as dino oil.

I started using synthetic oil with my '92 Vette and I still use it. Mostly Mobil 1. I started changing oil filters every 3-4 thousand miles and changing oil every 12-15K miles with my '92 Vette based on other comments I picked up here.

I figure the oil filter is the limiting factor on most cars because it is so small and synthetic oil can have a long life compared to dino oil.

My "proof" was when my '92 Vette had 103K miles and had been treated to synthetic oil all this time with filter changes every 3-4K and complete oil changes every 12-15K miles. I had the LT1 upgraded with LT4 heads, intake and the Hot Cam then. When the engine was pulled apart for that and a "rebuild", the mechanic showed me NO wear on the cylinders and everything looked like it was a brand new engine. Rings and bearings were replaced with new, as new built sizes. The inside of my engine looked like it was only a few months use instead of 12 years old and 103K miles.

I've been using synthetic oil on all my engines since and during that time and I change the oil filter every 4-5K miles now and the oil every 15K because of what I saw with my old '92 Vette.

I'm sold on synthetic oils (specifically Mobil 1) because of the life of the oil and how they protect the engines over time.

I understand that there are better oils for racing and max performance that Mobil 1, but for a street driven car, Mobil 1 is my go to oil.

 

[kpic]

Mobil says it better than I can
Synthetic oil vs. conventional oil | Mobil™ Motor Oils

Another good read:
http://www.topspeedracer.com/synthetic-vs-regular-oil.html

Other than the shaft speed in a turbo or centrifugal is not 200K RPM, the Mobil article is good stuff.

A shaft (cam, crank or etc.) does not contact the bearing or bushing; they run on a hydrodynamic film. Or they run on the oil between them and this is where synthetic shines as compared to "dino" oil.

It really isn't a sales pitch.

 

[toobroketoretire]

Speaking Of Oil Films

Last summer I wound my 454" up to 6300 rpm one day and look at what happened! My #4 main bearing burned to a crisp and the crankshaft journal looked just as bad. But after removing the smeared-on aluminum from the journal with coarse then fine emery cloth I was able to install a new set of main bearings and now have about 35,000 miles on them. Amazing huh?

 

[Mac]

Last summer I wound my 454" up to 6300 rpm one day and look at what happened! My #4 main bearing burned to a crisp and the crankshaft journal looked just as bad. But after removing the smeared-on aluminum from the journal with coarse then fine emery cloth I was able to install a new set of main bearings and now have about 35,000 miles on them. Amazing huh?

Ouch… :ugh

Mac

 

[toobroketoretire]

Ouch… :ugh

Mac

I took the burned bearing halves to the automotive machine shop and told them my crankshaft only got 2 shallow scratches. In the 60 years they have been in business they had never seen a bearing fail that bad and not take the crankshaft with it. And amazingly the two rods next to that #4 main journal had perfect bearings with no damage to them whatsoever. Guess I was REAL lucky.

 

[Mac]

I took the burned bearing halves to the automotive machine shop and told them my crankshaft only got 2 shallow scratches. In the 60 years they have been in business they had never seen a bearing fail that bad and not take the crankshaft with it. And amazingly the two rods next to that #4 main journal had perfect bearings with no damage to them whatsoever. Guess I was REAL lucky.

Odd to only lose the single bearing… That has me wondering if the oil passage was plugged to that journal?

Mac

 

[LLC5]

Up until this last summer I had been using Valvoline 10W30 conventional oil but when I found I could buy full synthetic Parts Master 10W30 for almost the same cost I made the switch. When I got home with my new oil I ran a test using a small quantity of conventional oil and the new synthetic oil. I put an old 12" aluminum skillet on my stove and put a cap full of each oil on opposite sides of the skillet and turned the burner on HIGH. After several minutes the conventional oil began smoking but the synthetic didn't smoke at all. After about 10 minutes smoke was billowing off the conventional oil but the synthetic still wasn't smoking. After about 15 minutes the conventional oil was turning to ash but the synthetic was barely smoking so I found the synthetic oil can resist heat a LOT better. After I put the synthetic in my 454" engine I noticed it stayed clear for a very long time which indicates the synthetic oil wasn't getting coked from the heat of combustion like the conventional oil always did. So I'm hooked and will run synthetic oil from now on.

The next time I need to cook engine oil on an aluminum skillet I'll keep this in mind............

 

[SVO]

At one time, Mobil stated that when using their synthetic oil, that you should follow the manufactors oil change schedule. So if GM says change oil every 3000 miles for your 1968 batmobile, you should change the oil at 3000 miles wheter you are using conventional or synthetic oil. They make no recommendation for extended mileage oil changes.

The 88 or 89 Corvette (I thinK) was the first model to come from the factory with synthetic oil with an extended oil change schedule to 10,000 or 12,000 miles. Synthetic oil reduced the heat developed in the valve train enough that Chevrolet was able to delete the oil cooler and lines found on the 84 & up Corvettes.

I think the oil filter you use is more important than oil you use, but that's just me. If synthetic works for you, then drive on.

 

[Vettehead Mikey]

Synthetic oil reduced the heat developed in the valve train enough that Chevrolet was able to delete the oil cooler and lines found on the 84 & up Corvettes.

Not quite. After engine shutdown, heat soakback could cause conventional oil to 'coke' in certain critical areas. GM had the choice to use a cooler to keep the oil at a more reasonable running temp, suitable for conventional oil, or to delete the cooler but require synthetics.

The difference in friction coefficient on a valve train is not enough to make much difference by dino and synthetic.

 

[Crimson Thunder]

I don't want to think about the beating I would get if I cooked oil in one of "Her" pans on the stove in "Her" kitchen.:L I actually use Mobil1 in both my daily drivers but I don't put enough miles on my Corvette to justify it. I just change it once a year with plain jane Valvoline 10w30.

 

[kpic]

For me, the advantage of synthetic oil is the life of the oil. It doesn't need to be changed as often as dino oil.

I started using synthetic oil with my '92 Vette and I still use it. Mostly Mobil 1. I started changing oil filters every 3-4 thousand miles and changing oil every 12-15K miles with my '92 Vette based on other comments I picked up here.

I figure the oil filter is the limiting factor on most cars because it is so small and synthetic oil can have a long life compared to dino oil.

My "proof" was when my '92 Vette had 103K miles and had been treated to synthetic oil all this time with filter changes every 3-4K and complete oil changes every 12-15K miles. I had the LT1 upgraded with LT4 heads, intake and the Hot Cam then. When the engine was pulled apart for that and a "rebuild", the mechanic showed me NO wear on the cylinders and everything looked like it was a brand new engine. Rings and bearings were replaced with new, as new built sizes. The inside of my engine looked like it was only a few months use instead of 12 years old and 103K miles.

I've been using synthetic oil on all my engines since and during that time and I change the oil filter every 4-5K miles now and the oil every 15K because of what I saw with my old '92 Vette.

I'm sold on synthetic oils (specifically Mobil 1) because of the life of the oil and how they protect the engines over time.

I understand that there are better oils for racing and max performance that Mobil 1, but for a street driven car, Mobil 1 is my go to oil.

I do about the same thing; you're one of the few I've met that does it. I change filters every 5K and oil every 10K. Blower oil every 5K. Same here and Mobile 1 is the only oil in the cabinet in the garage. I use it in all the vehicles, mowers, tillers, and even to lube the chains on the saws.
I was an OEM or vehicle manufacturer in engine design for 20 years and they test everything. synthetic wins. The best dino oil is Shell Rotella T. They disassemble an engine and measure everything. Then run an engine on a full durability cycle; after XXX hours, they disassemble it, measure everything and take pictures.

Being sold is an opinion and mine agrees with yours. However, the fact of the matter is; synthetic is better than dino oil in hydrodynamic applications.

Getting to sound too much like work and I retired.


Vettehead Mikey
Valve trains and lifters are not in the hydrodynamic lubrication category. I would not base my opinion on the easiest components to lubricate and ignore the most complex.

Bushings and Plain Bearings - Lubrication | AST Bearings

Notice, when they discuss hydrodynamic lubrication; the illustration is a bushing/journal bearing and a shaft or a crankshaft and shell bearings; not valve train lubrication. It is what it is.

 

[Hib Halverson]

(snip)
The 88 or 89 Corvette (I thinK) was the first model to come from the factory with synthetic oil with an extended oil change schedule to 10,000 or 12,000 miles. Synthetic oil reduced the heat developed in the valve train enough that Chevrolet was able to delete the oil cooler and lines found on the 84 & up Corvettes.

The first Corvettes to be factory-filled with synthetic oil were the 1992 models with the LT1 engine. The oil was Mobil 1 5W30. The LT5 went to Mobil 1 5W30 factory-fill in 1993.

As for deleting coolers and lines, only 84-91s with Z51 had KC4. Non-Z51s didn't have KC4.