Castrol GTX vs Mobil 1

[bob_ninja]

For short trips up to 10 min you certainly want to go with a lower viscosity and/or synthetic.
For instance, if recommended oil is 5W30 then use 0W30 instead, or 0W20 instead of 5W20. 0Wxx oils are usually synthetic anyway.
For my old Civic (5W30) I just started switching to 5W20 at this time of year, but many board members insist on sticking to manual's instructions.

So long as you use a 0Wxx oil it should work very well for you.

 

[heathenbrewing]

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5w-30 is the same viscosity in conventional or syn. This mindset that syn is more "slippery" is not fact.

Using 5w-xx oils over 20-xx oils will help the engine. Esp in the colder temps. Agree with that!

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Synthetic oils do not thicken as much on cooling. They have better fluidity as the temperature drops. A synthetic oil that is labeled as 5W-30 is less honey like as a mineral based 5W-30 motor oil at startup. They both have a thickness of 10 at normal operating temperatures. At 75F the synthetic is not as thick. At 32F the difference between the two is even greater. At 0F the mineral oil is useless yet the synthetic works fairly well.

Syn IS more "slippery" (for lack of a better word off the top of my head) for the same reason it flows faster in cold mornin starts....because it is made up of smaller molecules. Dino in comparison, is a mix of long-chain, med-chain and short-chain hydrocarbons.

 

[heathenbrewing]

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Dino base stock molecules are long carbon chains that are sensitive to stress and heat. Additionally, various paraffins that are contained in all petroleum products regardless of how well refined they are, cause oil to jell like a syrup at extremely cold temperatures. At the other end of the temperature spectrum, high engine temperatures and heavy loads cause these chains to break down and the base stock actually boils off causing a change of viscosity and the formulation of sludge. This can happen at temperatures as low as 230º F and by 250º F many petroleum oils are suffering significant breakdown.
Synthetic oils on the other hand are engineered specifically to provide all the lubricating properties that natural oil possesses, but none of the cold thickening or hot thinning properties of petroleum oil. Synthetics are made up of uniformly shaped molecules with shorter carbon chains which are much more resistant to heat and stress. Synthetics can withstand temperatures of 300ºF all day long and still protect your engine. In fact the American Society of Testing Materials (ASTM) standard wear resistance tests are conducted at 302º F. In this test synthetic lubricants far out perform petroleum lubricants by factor of four to one and greater.

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Let us know were you got this quote..

Thanks, bill

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Don Stevens. He is a mechanical engineering graduate of the Ohio State University.

 

[Bill in Utah]

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Don Stevens. He is a mechanical engineering graduate of the Ohio State University.

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Sounds like Amsoil dealer info.

I'd bet he is a dealer for them.

But your statements like this; "At 0F the mineral oil is useless yet the synthetic works fairly well" is pure nonsense.

I've only used conventional oils for over 30 plus years at 0f and below and NEVER had a problem. My UOA above for Castrol GTX 5w-30 which was over winter PROVES conventional oil works in cold temps.

Wonder how my engines last hundreds of thousands of miles using "useless" oil?

40 below zero, I'd agree that Syn works better.

at zero, its fine.

Also, to set things straight. There are many different types of Amsoil salesmen.

Gary and Pablo.

And the others. Some will do ANYTHING to sell you something. And sell you stuff you do NOT NEED.

Gary and Pablo will be the first to sell you something you WANT but will not blow B S around to make a sale. That is why I BUY stuff from people like them.

Let me know if your Don Stevens is a salesperson. I.E. has something to gain posting info like you are quoting.

We have some members here who post (and some that are gone) that post this brand is the ONLY choice. People who post like that are full of it.

There are many choices.

Take care, bill

 

[buster]

Don Stevens is an Amsoil dealer. What he said is true. No one sees those oil temps though. However, if you do have a turbo or see high temps, synthetic is the way to go. Bill, put Mobil 1 on the grill and any SM conventional oil and run it at 350-450F for awhile and see for yourself.

That said, 99% of us don't need synthetics.

 

[jmac]

I was sure glad I was using a syn when my thermostat started sticking on a day trip to Texarkana this summer and the temp guage started climbing first past half way, then topped at 90%, never hit red but it was too high. Think oil must have been at least around 250 but who knows what it was? Fixed thermostat and oil didn't seem too bad but switched it out less than 3000mi as thinking it must have degraded some even so. I was trying out Syntec 5w-30 since I had picked a 5 qt jug a a fairly good price.

 

[heathenbrewing]

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Don Stevens. He is a mechanical engineering graduate of the Ohio State University.

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Sounds like Amsoil dealer info.

I'd bet he is a dealer for them.

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Don Stevens is also a member of the Suncoast Region of the PCA and BMWCCA for 14 years. He is also a 10-year veteran road racer/driving instructor with hundreds of hours of seat time and several endurance race wins to his credit.

I am pretty sure he doesnt sell Amsoil.

www.drivewerks.com/tech/mult_s - [Cached]
Published on: 1/9/2007

 

[heathenbrewing]

Again, my whole point was that syn offers more protection over dino. That is all.

 

[Blackplastic]

If you run your car hard use synthetic.
If you drive like a old grandma use dino.

 

[Bill in Utah]

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Again, my whole point was that syn offers more protection over dino. That is all.

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Doing some checking he DOES sell Amsoil.

The big question is do you NEED the so called protection.

Like Buster said, most people don't and its $$$ down the drain.

Today, my wife got hit by a semi in our new Outback. She is ok, the outback is not. I did have 99 cent PP syn in it and guess what, the tow truck driver did not treat it any better and the insurance company could care less what oil is in it.

Thats the day I'm having.. I just got done washing it 5 mins before...

But the guy your quoting does sell it.

Bill

 

[Bill in Utah]

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If you run your car hard use synthetic.
If you drive like a old grandma use dino.

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What a statement.

 

[ThirdeYe]

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Again, my whole point was that syn offers more protection over dino. That is all.

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Doing some checking he DOES sell Amsoil.

The big question is do you NEED the so called protection.

Like Buster said, most people don't and its $$$ down the drain.

Today, my wife got hit by a semi in our new Outback. She is ok, the outback is not. I did have 99 cent PP syn in it and guess what, the tow truck driver did not treat it any better and the insurance company could care less what oil is in it.

Thats the day I'm having.. I just got done washing it 5 mins before...

But the guy your quoting does sell it.

Bill

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Bill! I'm sorry to hear that. I'm glad your wife is okay, and I'm sorry to hear about the Subaru. It seemed like such a nice car. But the fact that your wife is okay is the most important thing.

 

[02zx9r]

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Again, my whole point was that syn offers more protection over dino. That is all.

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Doing some checking he DOES sell Amsoil.

The big question is do you NEED the so called protection.

Like Buster said, most people don't and its $$$ down the drain.

Today, my wife got hit by a semi in our new Outback. She is ok, the outback is not. I did have 99 cent PP syn in it and guess what, the tow truck driver did not treat it any better and the insurance company could care less what oil is in it.

Thats the day I'm having.. I just got done washing it 5 mins before...

But the guy your quoting does sell it.

Bill

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Bill! I'm sorry to hear that. I'm glad your wife is okay, and I'm sorry to hear about the Subaru. It seemed like such a nice car. But the fact that your wife is okay is the most important thing.

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Sorry to hear!

 

[Greggy_D]

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Today, my wife got hit by a semi in our new Outback. She is ok, the outback is not.

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Sorry to hear that Bill. Hope everything is alright.

 

[Bill in Utah]

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Today, my wife got hit by a semi in our new Outback. She is ok, the outback is not.

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Sorry to hear that Bill. Hope everything is alright.

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Thanks guys!

Broke the rear axles (and control arms, ABS stuff(most of the rear end) along with major body damage to the rear. About 8-10k they think.

We will be spending some time in court I can see. Both with the local police and insurance companies.

I just hope they can fix CORRECTLY the Subaru.

I'll keep you guys up to date.

This is our first accident. Wife has been driving almost 30 years and I've been driving over 30 years and million plus miles with out an accident that was my fault. (and those accidents were in the work outfits)

I've never had a ticket and she had one when she was in her 20s.

Sucks. Esp with a newer car. (I had washed/waxed it 10 mins before the accident..)

Sorry about being

Bill

 

[SargeGTO]

If you would have been running a synthetic oil in there the semi would have never hit your car.
Glad to hear Mama in Utah is safe and not hurt for sure! It is dangerous out there....

 

[ARB1977]

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I am going to use my GTX for the warm month's. I will use the SYNTEC for winter month's. It keeps me from having to change the oil during the cold times.

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It also adds hair on your chest.

 

[Bill in Utah]

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If you would have been running a synthetic oil in there the semi would have never hit your car.
Glad to hear Mama in Utah is safe and not hurt for sure! It is dangerous out there....

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There was syn in the engine. 99 cent PP. About 1k miles on it.

The police have screwed up the accident report so we will be going to court just for the accident report.

Hopefully the Outback will be fixed correctly.

Bill

 

[Lonnie]

Back to the original question. You don't have to worry. Mobil 1 is just as good as Castrol GTX. If you are using GTX and want to switch you can feel confident that Mobil 1 will perform as well as GTX. GTX has one advantage. It's cheaper and you can change it more often. Again, don't worry. If you do start using Mobil 1 you can expect it to lubricate as well as your current GTX.