Engine oil question

[buickanddeere]

If it's not a PAO or Ester oil that meets group four specs . It's not really a synthetic , it's just re-refined mineral oil. Mobile 1, royal Purple and Amsoil are real synthetic .

 

[bdog]

My 2015 power stroke and my m59 kubota that I recently sold both specified 10-30. I think my two rtv-900x's want 10w30 as well. They all get 5w40. I buy the delo because it was slightly cheaper vs rotella when I went there and I buy pallets at a time. I think the delo and rotella are very similar quality wise. I buy whichever is on sale.

My older and larger diesels like my 1980 4440, my 98 kenworth, 98 international, all get 15-40 because they have thousands of hours on it so why change now and some of them take upwards of ten gallons of oil so it is costly to change them. I don't see the benefit of switching at this point on a machine that ran 8000 hrs already on 15-40 but when I buy something new I spring the extra for the synthetic.

After I wrote that out it doesn't make much sense because if the 15-40 got my old machines 8000+ hours why do I need something better in the new ones? I probably don't but it makes me feel good. I do notice in my pickup it turns over faster on cold mornings.

 

[Soundguy]

My 2015 power stroke and my m59 kubota that I recently sold both specified 10-30. I think my two rtv-900x's want 10w30 as well. They all get 5w40. I buy the delo because it was slightly cheaper vs rotella when I went there and I buy pallets at a time. I think the delo and rotella are very similar quality wise. I buy whichever is on sale.

My older and larger diesels like my 1980 4440, my 98 kenworth, 98 international, all get 15-40 because they have thousands of hours on it so why change now and some of them take upwards of ten gallons of oil so it is costly to change them. I don't see the benefit of switching at this point on a machine that ran 8000 hrs already on 15-40 but when I buy something new I spring the extra for the synthetic.

After I wrote that out it doesn't make much sense because if the 15-40 got my old machines 8000+ hours why do I need something better in the new ones? I probably don't but it makes me feel good. I do notice in my pickup it turns over faster on cold mornings.

We bought a 80 mack tractor that had over 800k on it, original mains. we ran it to almost 2m and sold it.

in that time it went thru an injector pump.. and air pump, and a couple rear and rear rear gear sets.

Lotsa miles on ground up dinosaurs... but as you say.. it holds many many gallons of oil... that must make more of a difference than some of the other oil specifics.

 

[arrow]

As I remember... the oil weight numbers mean the viscosity at temperature
example: 5w40 means the oil viscosity starts as a 5w (winter) and at operating temperature thins like 40.

Using this in place of a 10w-30 simply means the oil viscosity will be thicker at operating temperature, wasting fuel. The up side is the oil will flow better at start.

Here's a link that explains in better detail .. Motor Oil Viscosity Grades Explained in Layman's Terms

You mean "thickens" like 40.

 

[hosspuller]

You mean "thickens" like 40.

No ... I don't think so. To say the oil thickens means the oil viscosity increases with temperature. This is untrue. All oil "thins" as viscosity decreases or flows better as temperature is increased. TAR is solid at room temp. heat it to 200 degrees and it flows or "thins".

A straight 40 weight oil at 32 degrees F flows like honey... At 210 degrees, the same 40 weight will flow like water.
A straight 5w oil at 32 degrees flows like water, at 210 degrees, the same 5 weight is so thin the lubrication is gone.

a 5w-40 flows like water at 32 degrees and maintains / "thins" to the same viscosity at 210 degrees as a straight 40 weight oil. (flow descriptions are for example only. Actual Centipoise value may be different) The difference is viscosity improvers and the molecular structure of the oil.

 

[MESSMAKER]

It's always safest to use oil with the viscosity indices recommended in your owners manual. It's usually depends on the range of ambient temperatures you will encounter during use.

I think that goes without saying. I think poster knew what was to be used but was trying to find out if it was a hard fast rule or just a recommendation.

 

[rswyan]

I'm running M1 5w40 Turbo Diesel Truck in our B2910 ... have run Rotella T6 5w40 as well.

 

[TSO]

Both my Massey and my PowerStroke call for 10w30 ... And I have tried 10w30 in both of them, however I feel that they run better with 5w40 and so now I run 5w40 synthetic in them.

 

[arrow]

No ... I don't think so. To say the oil thickens means the oil viscosity increases with temperature. This is untrue. All oil "thins" as viscosity decreases or flows better as temperature is increased. TAR is solid at room temp. heat it to 200 degrees and it flows or "thins".

A straight 40 weight oil at 32 degrees F flows like honey... At 210 degrees, the same 40 weight will flow like water.
A straight 5w oil at 32 degrees flows like water, at 210 degrees, the same 5 weight is so thin the lubrication is gone.

a 5w-40 flows like water at 32 degrees and maintains / "thins" to the same viscosity at 210 degrees as a straight 40 weight oil. (flow descriptions are for example only. Actual Centipoise value may be different) The difference is viscosity improvers and the molecular structure of the oil.

I think we have a "semantical" misunderstanding. No 5 weight can act like a 40 nor can it get to 40. The two numbers in multi viscosity oils are measured differently. As 40 is "thicker" than 5 I used the term to describe the weight or "thicker" oil thus "thickens like 40" as it relates to 5w-40, . You on the other hand were describing heating the oil and thus increasing it's flowability. I do believe that multi viscosity oils are measured at different temps with the high side measured at a higher temperature to "act" like it's designation.

Now here is an interesting tidbit. Oil technology is as complex as it can get. It was not until 2009 that the oil manufacturer "Royal Purple" who supplies most oil to nitro methane burning dragsters, developed an oil that they thought finally met the requisites for such a violent environment as the inside of a fuel dragster engine. They start off with straight 70 weight synthetic. Halfway down the track or when the dragster is at it's peak hp, it alters and acts like 90 weight so as to absorb heat better and give reciprocal stability to engine parts. When it is drained from the car at the end of the run, it comes out like 30 weight mostly because it has been contaminated with nitro methane as well as getting beat up by the high temps. It is contaminated as a result of the dragster from start up to shut down, using about 20 gallons of fuel but not all of it got "burned". How a straight weight oil gets to a higher designation as friction increases is beyond me so I cannot give you the "whys" in such a case.

 

[DarkBlack]

I think we have a "semantical" misunderstanding. No 5 weight can act like a 40 nor can it get to 40. The two numbers in multi viscosity oils are measured differently. As 40 is "thicker" than 5 I used the term to describe the weight or "thicker" oil thus "thickens like 40" as it relates to 5w-40, . You on the other hand were describing heating the oil and thus increasing it's flowability. I do believe that multi viscosity oils are measured at different temps with the high side measured at a higher temperature to "act" like it's designation.

Now here is an interesting tidbit. Oil technology is as complex as it can get. It was not until 2009 that the oil manufacturer "Royal Purple" who supplies most oil to nitro methane burning dragsters, developed an oil that they thought finally met the requisites for such a violent environment as the inside of a fuel dragster engine. They start off with straight 70 weight synthetic. Halfway down the track or when the dragster is at it's peak hp, it alters and acts like 90 weight so as to absorb heat better and give reciprocal stability to engine parts. When it is drained from the car at the end of the run, it comes out like 30 weight mostly because it has been contaminated with nitro methane as well as getting beat up by the high temps. It is contaminated as a result of the dragster from start up to shut down, using about 20 gallons of fuel but not all of it got "burned". How a straight weight oil gets to a higher designation as friction increases is beyond me so I cannot give you the "whys" in such a case.

How does the oil know the car is halfway down the track?
How does it know the engine is making its maximum power?