Synthetics for the 6.5 & synthetics in general

[Detroit Dan]

I switched to 5W40 synthetic mid way through last winter, then went back to 15W40 for the summer. Next change I'll go back to the lighter oil.

15w40 synthetic or non synthetic? Because I've heard it's a no-no to change back to dino after using synthetic for any length of time. Not sure if it's true, but I've heard it.

I used to switch to 10w40 in winter for easier starts, but it always made me a little nervous so for years now I've been running just 15w40 year round

 

[Brooklyn Tow]

From what I understand it's ok........Search maintenence/fluids and/or post up and Wrecker (In house oil expert) will give you all the details you want.

 

[Matt Bachand]

15w40 synthetic or non synthetic? Because I've heard it's a no-no to change back to dino after using synthetic for any length of time. Not sure if it's true, but I've heard it.

I used to switch to 10w40 in winter for easier starts, but it always made me a little nervous so for years now I've been running just 15w40 year round

Yep ol' wives tale... probably started by the synthetic oil industry. I cheaped out last spring and went dino as I was broke but wanted to give her a change up after winter. I just switched back to mobil-1 and THe smoothness, and quietness, fast cranking, and increased turbo spool and sound all came back by simply turning the key.


These engines love synthetic.

 

[Dave01]

I run veg so I want short oil change intervals, 3000 miles, regardless of what type of oil I'm running. I think the 15W40 dino is fine for warm weather, but after experiencing the slow cranking of that oil last winter I switched to the 5W40, a major difference in cranking speed.

I used to switch to 10w40 in winter for easier starts, but it always made me a little nervous so for years now I've been running just 15w40 year round

Dan, was the 10W40 diesel rated? I wasn't aware there was any that weight for diesels. Anyway, I saw no oil pressure drop with the 5 weight, I'm confident it's a fine oil for my truck in winter.

 

[Matt Bachand]

I run veg so I want short oil change intervals, 3000 miles, regardless of what type of oil I'm running. I think the 15W40 dino is fine for warm weather, but after experiencing the slow cranking of that oil last winter I switched to the 5W40, a major difference in cranking speed.



Dan, was the 10W40 diesel rated? I wasn't aware there was any that weight for diesels. Anyway, I saw no oil pressure drop with the 5 weight, I'm confident it's a fine oil for my truck in winter.

I ran the 0/40 last year it was great.

You wont notice any pressure drop because the 0 or 5 is the cold flow rating, when its warm the thickness is the same, at 40.


Indeed, extrememly important to get a diesel rated oil. One that is made for Compression combustion, not Spark Combustion.

 

[Wrecker]

Yep ol' wives tale... probably started by the synthetic oil industry. I cheaped out last spring and went dino as I was broke but wanted to give her a change up after winter. I just switched back to mobil-1 and THe smoothness, and quietness, fast cranking, and increased turbo spool and sound all came back by simply turning the key.


These engines love synthetic.

You are spot on Matt, switching is of absolutely no consequence.

The first rating, 15w for example, is the oil's viscosity grade at 40C (104F), the second number, say 40, is at 100 C (212F).

Calling the first a "cold" number is a little bit inaccurate. The Pour Point using the standardized ASTM D-97 test is a much better measure of cold weather performance.

For example, Amsoil AME 15w-40's pour point is -44F, where Chevron Delo 400 15w-40 has a pour point of -23F.

All engines love synthetic, better lubrication in a machine makes it happier!

Hope this helps.

 

[Dave01]

The first rating, 15w for example, is the oil's viscosity grade at 40C (104F), the second number, say 40, is at 100 C (212F).

Thanks for the details Wrecker, very helpful! Does the viscosity transition happen gradually over the 108 F range, or is there a narrow band of temp where most of the transition happens?

I'm curious because on cold winter days, even with a winter front on, it can take a long time to get up to operating temp. If my driving is around town it might never get up to stat temp, maybe hover around 170 or so until I get on the highway and put some load on the engine. So, in the case of 5W40, I'm wondering whether at 160-170 F the oil is more like a 5 weight or somewhere inbetween, like maybe 30 weight.

Interesting stuff!

 

[Wrecker]

The change is not linear, and there is some variation between brand/formulation.

Oils evacuate (evaporate) moisture once the engine is at normal operating temperature for a given period of time. That's why short trips is considered severe service by most manufacturers.

If your engine doesn't get to normal operating temp on a regular basis, I would suggest shorter oil change intervals/analyisis to ensure you are not running an oil that is prematurely expended.

 

[Dave01]

Actually I get up to operating temp a lot, and for long runs, I put on about 30,000 miles/year right now. I was just curious about the around town trips, how the oil reacts.

I'm changing at 3,000 miles anyway so I do a lot of oil changes in a year!

I had a feeling it wasn't linear, and now you've confirmed that. I'm now going to check out the pour point on some oil brands/types that I use in various vehicles to see how they compare.

 

[dragogt]

You are spot on Matt, switching is of absolutely no consequence.

The first rating, 15w for example, is the oil's viscosity grade at 40C (104F), the second number, say 40, is at 100 C (212F).

Calling the first a "cold" number is a little bit inaccurate. The Pour Point using the standardized ASTM D-97 test is a much better measure of cold weather performance.

For example, Amsoil AME 15w-40's pour point is -44F, where Chevron Delo 400 15w-40 has a pour point of -23F.

All engines love synthetic, better lubrication in a machine makes it happier!

Hope this helps.

Thats apples to oranges, Synthetic to dyno.. What the comparison to Castrol syntc, Mobil One, or synthetic Rotella 15w40?

 

[Wrecker]

Thats apples to oranges, Synthetic to dyno.. What the comparison to Castrol syntc, Mobil One, or synthetic Rotella 15w40?

That was my point, I was answering a specific question.

I can't find any Castrol Syntec product in 15w-40, if there is one, I missed it. I only see Tection Extra and GTX Diesel, neither are synthetic products as far as I know.

As far as Rotella 15w-40 goes, I have not been able to find a spec sheet that lists numbers from Shell. They have a bar graph layout comparing their oil to the previous formulation and to dino Rotella, but no real specs that I can find.

I'm sure the data is out there somewhere, but I can't find it. If someone finds some, post a link and we'll compare all of the specs.

 

[Turbine Doc]

Thats apples to oranges, Synthetic to dyno.. What the comparison to Castrol syntc, Mobil One, or synthetic Rotella 15w40?

I've been on a lot of forums since 2000 when I got my 1st 6.5, I've never seen a study of one syn vs another, I'm sure there are differences, and probably Wrecker could provide Amsoils marketing pitch, but that would be kind of a dino v dino sellers discussion "ours is better because ....." & Iv'e never seen Wrecker depart from anything other than if you can afford it syn is better than dino, and he avoids that 1 synthetic brand is superior to another.

Based off of oil samples I've run both syn & dino, I tend to agree with that assessment & ans to the original question that overall syn is superior to dino, but a good modern quality blend such as Rotella or Delo is good also, if changing often that might be the better $ to benefit ratio, especially if you feel your veggie requires more frequent change.

What would be interesting is if one of you veggie guys ran a sample program to dispel or confirm that oil actually needed to be changed at 3K interval; in running samples on my personal vehicle with bypass filtration and dino or amsoil I'm safe to 20K miles on my oil, I'm pushing my current batch of amsoil to 25 K to see how it fares with that many miles on it.

 

[dragogt]

That was my point, I was answering a specific question.

I can't find any Castrol Syntec product in 15w-40, if there is one, I missed it. I only see Tection Extra and GTX Diesel, neither are synthetic products as far as I know.

As far as Rotella 15w-40 goes, I have not been able to find a spec sheet that lists numbers from Shell. They have a bar graph layout comparing their oil to the previous formulation and to dino Rotella, but no real specs that I can find.

I'm sure the data is out there somewhere, but I can't find it. If someone finds some, post a link and we'll compare all of the specs.

I found this but it doesn't mean much to me I'll let you decipher it.. http://forums.tdiclub.com/showthread.php?t=215098

 

[Wrecker]

Below is the table from the link. These are all CJ-4 oils, not what I would recommend for a 6.5 or any other non DPF diesel application.

Some of the reasons are these:

1) The highest TBN (Total base number) of any oil on the list is 10.7, Amsoil AME 15w-40 has a TBN well over 12. AME will reduce more acids introduced into the oil, providing longer service life and drain intervals.

2) NOACK Volatility (ASTM D-5800) tells you how badly the oil "cooks off" or "evaporates" while in service. It is measured in % loss, a lower number is better. Red Line does very well in this regard with 6%, Amsoil AME 7%. (You'll notice due to drastically different formulation strategies that Red Line only has a TBN of 8, compared to AME's 12.)

3) Pour points are generally in the -40 something C range with the outliers being Rotella 5w-40 the weakest at -36C and Duron 0w-40 putting a spanking on everyone with a -66C result. (That's a big concern for you Ice Road Truckers). All perform better in this category than most Dinos.

This is just a quick look at some of the high points. One needs to look at the performance of a given lubricant in aggregate compared to the competition based on a specific application.

There is no such thing as "The Best Oil", just one which has the best set of compromises for a given application. It's kind of like playing Whack-A-Mole when formulating a lubricant, as one performance attribute is improved, another suffers.

I hope this answers more questions than it creates.

Ashton

 

[Dave01]

What would be interesting is if one of you veggie guys ran a sample program to dispel or confirm that oil actually needed to be changed at 3K interval

What we would be looking for is the presence of veg in the oil. Would anything in the oil analysis indicate that? The polymerization doesn't just raise viscosity, it actually turns the oil into jelly. I have no idea what is going on chemically, so not sure what you'd look at for analysis.

I'll get it analyzed before the next change. Where's the easiest place to send it?

 

[Wrecker]

Yes, you would need to monitor for these and any other parameters off or going off normal.

Fuel dilution resulting in viscosity reduction.

Depletion of alkalinity reserve in the oil indicated by total base number decrease.

Total acid number increasing more rapidly, indicating oil degradation from more NOx acid formation.

Certain metals such as copper and lead leached from bearings due to fuel in the engine oil.

 

[Matt Bachand]

Below is the table from the link. These are all CJ-4 oils, not what I would recommend for a 6.5 or any other non DPF diesel application.

Some of the reasons are these:

1) The highest TBN (Total base number) of any oil on the list is 10.7, Amsoil AME 15w-40 has a TBN well over 12. AME will reduce more acids introduced into the oil, providing longer service life and drain intervals.

2) NOACK Volatility (ASTM D-5800) tells you how badly the oil "cooks off" or "evaporates" while in service. It is measured in % loss, a lower number is better. Red Line does very well in this regard with 6%, Amsoil AME 7%. (You'll notice due to drastically different formulation strategies that Red Line only has a TBN of 8, compared to AME's 12.)

3) Pour points are generally in the -40 something C range with the outliers being Rotella 5w-40 the weakest at -36C and Duron 0w-40 putting a spanking on everyone with a -66C result. (That's a big concern for you Ice Road Truckers). All perform better in this category than most Dinos.

This is just a quick look at some of the high points. One needs to look at the performance of a given lubricant in aggregate compared to the competition based on a specific application.

There is no such thing as "The Best Oil", just one which has the best set of compromises for a given application. It's kind of like playing Whack-A-Mole when formulating a lubricant, as one performance attribute is improved, another suffers.
I hope this answers more questions than it creates.

Ashton

So an oil specifically designed for turbo diesel trucks may actually be more than a marketing hype and may have some truth to it being better, than just a blanket 5w-40 synthetic oil statement??