Synthetic vs. Dino

[fordman65]

I was told years ago by a mechanic, that you can run thicker synthetic oils and get the same lubricating properties as a thinner dino oil. Example if you ran a 10w30 dino oil and then switched to a thicker 10W-40 synthetic. That you would have almost the same lubricating properties as the thinner dino oil.
The reason I would use a thicker synthetic oil is for the motor protection with the benefits of synthetic.
I like protecting my motors, so I guess I am a little old school with my preference toward a thicker oil.
I am new to the board and I hope this is not a stupid question.
Asking to find out if my mechanic was right.

 

[SrDriver]

I would just use the correct weight oil by either looking into the owners manual or on the oil fill cap.

Both our vehicles call for 5W20 oil and we use Synthetic 5W20 year around.

My wife and I live just a few miles from the Florida line and see long hot summers and have no problems.

 

[bullwinkle]

The thicker synthetic will be thicker at operating temperature than the thinner dino oil-causing a loss of fuel economy & actually raising oil temps slightly. I would stick to your mfr.'s recommendation, unless you have a high-mileage, worn, out of warranty engine with high bearing tolerances-then a little higher viscosity is OK.

 

[1999nick]

Originally Posted By: bullwinkle
The thicker synthetic will be thicker at operating temperature than the thinner dino oil-causing a loss of fuel economy & actually raising oil temps slightly. I would stick to your mfr.'s recommendation, unless you have a high-mileage, worn, out of warranty engine with high bearing tolerances-then a little higher viscosity is OK.


Clearances.

 

[Eddie]

This is not a stupid question in my opinion. The original comment appears to be based on common sense and does have some validity. However; recommended oil viscosity is based on a number of things, some of which are relative to specific engine design parameters. Bearing temperature and clearance, available oil pressure at the bearing and oil throughput. One can't make a general statement that thicker is better and therefore the wise move is to stick with the oil viscosity recommended by your vehicle manufacture. Just my thoughts. Ed

 

[bruno]

That mechanic was talking pure nonsense .
Protection ?
Against what ?
Thicker oils provide poorer protection against cold start wear and degrade fuel mileage so the smart move is to use the specified weight and quality of oil for your car .

 

[yonyon]

Originally Posted By: fordman65
I was told years ago by a mechanic, that you can run thicker synthetic oils and get the same lubricating properties as a thinner dino oil. Example if you ran a 10w30 dino oil and then switched to a thicker 10W-40 synthetic. That you would have almost the same lubricating properties as the thinner dino oil.
The reason I would use a thicker synthetic oil is for the motor protection with the benefits of synthetic.
I like protecting my motors, so I guess I am a little old school with my preference toward a thicker oil.
I am new to the board and I hope this is not a stupid question.
Asking to find out if my mechanic was right.


I suspect that in response to a question you asked or just as part of the general flow of conversation your mechanic just spouted off some bull so as not to come off as uninformed. Most likely he had no idea whether or not what he was saying had any basis in reality and just wanted to sound like he knew what he was talking about. It's just good business.

 

[fordman65]

Protection from upper cylinder wear, and valve train wear. Piston and ring scarring.

 

[Garak]

Some of that may have had some validity many years ago, particularly when certain multigrade minerals oils weren't so great. If this was around 1980, and I had to choose oil for a vehicle that could use 10w30 or 10w-40, if I had to go with the 10w-40, I would have preferred synthetic. If I chose 10w30, I'd be using conventional, and that's what I did in fleet usage at the time. I stayed away from the thicker oils altogether.

But, that was years ago, as was your conversation with the mechanic. Conventionals have improved dramatically, and there aren't any new vehicles I can think of in North America that require a 10w-40. The only things calling for 40 grades (or heavier) are some European cars, some sports cars (GT500, some SRTs), and diesels. As far as synthetics go, 10w-40 is a pretty silly grade anyhow, if you ask me, when there are plenty of quality 5w-40 and 0w-40 choices available.

 

[fordman65]

I appreciate your kindness as to saying not a stupid question.

 

[fordman65]

My mechanic then and now in 03. He is a ASE certified mechanic. He was the head of a Ford dealership repair shop, until the dealership shutdown. I had asked him back in 03, when I had purchased my 01 Sable used. What oil weight he would recommend once the car hit 100k miles. I plan on keeping it until at least 200k miles.

 

[KCJeep]

I think he was alluding to the superior flow characteristics of synthetics when cold, that's all.

 

[Ken2]

Hot oil viscosity is measured at 100°C (212°F) for the purpose of the oil viscosity grade (or SAE weight). While there is a range of actual viscosities for each grade, the dino and the syn will both measure in this range. Every 30 wt will measure between 9.3 and 12.49 centistokes. When cold, both dino and syn 10W will measure less than 7,000 milliPascals at -25°C.

Mechanics do not receive much training in lubrication.

 

[fdcg27]

A 3.0 Vulcan is not at all picky about oil grade.
It will be fine with anything you want to use, although I believe that yours is a pre roller engine, so twenty grade should not be used per Ford.
We had a 3.0 Aerostar, and it saw everything from 5W-20 to 0W-30, 10w30, 10W-40, 5W-40, 5W-50 and 15w40, and it seemed fine on any of these grades.
The poor thing was totalled at 176K, still running great with no measurable oil consumption.

 

[yonyon]

Originally Posted By: Ken2

Mechanics do not receive much training in lubrication.


As a mechanic myself, I can attest to this.

Originally Posted By: fdcg27
A 3.0 Vulcan is not at all picky about oil grade.
It will be fine with anything you want to use, although I believe that yours is a pre roller engine, so twenty grade should not be used per Ford.


And this as well. My 97 Sable also has a 3.0 Vulcan and just turned 50,000 miles about 2 hours ago. It's had two oil changes, once with Citgo 10w30 and once with QSUD 5W30. So far it hasn't complained.

 

[zerosoma]

Check your manual

 

[Mitch Alsup]

Originally Posted By: fordman65
Protection from upper cylinder wear, and valve train wear. Piston and ring scarring.


Piston lands and rings are cleaned and lubricated better with thinner oils. Direct actuated Valve trains are lubricated better with thicker oils, rollerized valve trains are perfectly lubricated with thinner oils.

Journal bearings are cleaned and lubricateed with the proper viscosity oils that are highly dependent on the actual clearances and manufacturing tollerances.

So unless you know the specifics, you can't really know ehich way to go.