Thread: synthetic oils

Castrol 0W40 full synthetic.

Great oil and is designed for the fine tollerances of the TD5 motor. Reality is that there is very little between 0w and a 5W. I do mine every 10,000 Ks including filters

Originally Posted by nzlandies

The problem over here is that even 10 oil can be a bit thick for a td5 without being really cold, 5w is much tinner than a 10w even at 20c. The oil pump is then under too much load and brakes the chain. It can also wreck the by-pass filter.

Sorry, it's not that simple.

Example, Penrite HPR Diesel5 5W-40 that is commonly used in TD5's is almost exactly the same kinematic viscosity at 0*C as Redline 15W-40. (RL is actually a touch thinner)

They sport identical viscosity indexes and within the realms of manufacture, identical viscosities, so down to somewhere near -10*C they will act identically in terms of pumpability.

HPRD5 989cSt @ 0*C
RL 15W-40 967cSt @ 0*C

If you want to know an oils viscosity characteristics, you need to know it's viscosity at both 40*C and 100*C or one of those temps and it's viscosity index (VI) and plug the numbers into this Viscosity and Viscosity Index (VI) Calculation
This will be accurate down to somewhere between 0* and -10, maybe -15 before it all goes pear shaped and actual measurements need to be taken.

Originally Posted by rick130

Sorry, it's not that simple.

Example, Penrite HPR Diesel5 5W-40 that is commonly used in TD5's is almost exactly the same kinematic viscosity at 0*C as Redline 15W-40. (RL is actually a touch thinner)

They sport identical viscosity indexes and within the realms of manufacture, identical viscosities, so down to somewhere near -10*C they will act identically in terms of pumpability.

HPRD5 989cSt @ 0*C
RL 15W-40 967cSt @ 0*C

If you want to know an oils viscosity characteristics, you need to know it's viscosity at both 40*C and 100*C or one of those temps and it's viscosity index (VI) and plug the numbers into this Viscosity and Viscosity Index (VI) Calculation
This will be accurate down to somewhere between 0* and -10, maybe -15 before it all goes pear shaped and actual measurements need to be taken.

What does delvac 1 perform like?

Originally Posted by Captain_Rightfoot

What does delvac 1 perform like?

The 'old' CI-4/CI-4+ stuff, of which there is still a fair bit around is roughly 1066cSt at 0*.
The new CJ-4 Delvac 1 ESP works out at 973cSt at 0*.

Not enough of a difference to worry about.

As to actual performance against other oils ?
Delvac 1 has been held as the standard to which all other diesel specific oils are measured.
Some beat it in some applications/conditions, but it complies with and is tested against the widest range of manufacturer approvals of almost any oil.

I'm unconvinced it's worth it against good premium oils in engines like the 300Tdi, even though it's all I ran for years and years.
I potentially have some problems with my little 300Tdi that may be lube based, but I'm still checking/testing so can't really comment any further.

Originally Posted by rick130

The 'old' CI-4/CI-4+ stuff, of which there is still a fair bit around is roughly 1066cSt at 0*.
The new CJ-4 Delvac 1 ESP works out at 973cSt at 0*.

Not enough of a difference to worry about.

As to actual performance against other oils ?
Delvac 1 has been held as the standard to which all other diesel specific oils are measured.
Some beat it in some applications/conditions, but it complies with and is tested against the widest range of manufacturer approvals of almost any oil.

I'm unconvinced it's worth it against good premium oils in engines like the 300Tdi, even though it's all I ran for years and years.
I potentially have some problems with my little 300Tdi that may be lube based, but I'm still checking/testing so can't really comment any further.

Very interesting. The last time I bought it was over a year ago. The new drum arrived yesterday and it looks very similar but has a different part number. In my flu-ridden state I couldn't be bothered analysing more than that.

Rick 130,as we know synthetic refrigeration oils are much more hydroscopic than refrig mineral oils,and bugger all moisture can be tolerated in any refrigeration system.
Are synthetic motor oils as hydroscopic?If so is it that the moisture will not be enough to harm the engine oil & will boil off quickly once the engine is running.

Just something i have been wondering about for a while.........

Originally Posted by scarry

Rick 130,as we know synthetic refrigeration oils are much more hydroscopic than refrig mineral oils,and bugger all moisture can be tolerated in any refrigeration system.
Are synthetic motor oils as hydroscopic?If so is it that the moisture will not be enough to harm the engine oil & will boil off quickly once the engine is running.

Just something i have been wondering about for a while.........

Nope, no problem with car/truck lubricants.

It also depends on what 'synthetic' base we are talking about too.

Most all 'synthetics' these days are either Group III (severely hydrocracked mineral oils) or polyalfaoleofins (PAO's) and neither of these are hygroscopic to any great degree, even PAO refrigeration oils.

Pure esters can be very hygroscopic, as we know from refrigeration use, yet very few car type oils use predominantly ester bases.
Redline, Motul (both Poly-ol-esters, POE's) and Neo (di-ester) use them (and with Motul it is only their premium ranges), although almost everyone else uses lesser % of di-ester bases mixed with PAO's and Group III oils in their premium/competition oil bases.

It's the shear cost of POE's that precludes their widespread use.

The companies that do use them also 'buffer' the finished product against moisture, corrosion, stability and compatibility with seal materials (pure esters can only operate with a relatively limited range of seal materials) which is why you see a mix of bases.

Then we have Polyalkylglycols (PAG's), with the only automotive application I only know of being truck diffs/gear oils.
In refrigeration use these are the most hygroscopic oils of all (used in car a/c) and are incompatible with any other oils, yet most of the car service blokes drop POE's in on top of them.....

I've talked to an oil blender about refrigeration POE's and he reckons the moisture issue is overstated a little but I don't take any chances and blow dry nitrogen into a bottle when closing. I'll probably find out now that I'm contributing to oil nitration by doing that, but i can't stand the thought of wasting good oil who's only crime is that the can has been opened.


If anyone is interested, there is an excellent overview of esters in synthetic lubricants here An Overview of Esters in Synthetic Lubricants - Bob Is The Oil Guy

Tom used to be a Senior Vice president of HATCO, one of the major manufacturers/suppliers of ester lubricants worldwide and one of their senior Tribologists/blenders.



Some interesting tid bits here that I wasn't aware of.
Looks like low VI mineral oils still have some advantages.

Formulated PAOs will have anti-wear additives that go to the metal surface for start-up protection. Esters actually compete with the anti-wear additives and can make the formulation of an ester lubricant more of a challenge.

I work with refrigeration lubricants that use POE bases. We use TCP to provide some anti-wear and ferrous metal deactivation, but the activity of the TCP in POE is much less than in mineral oils because it has to compete with the polarity of the POE basestock.

Another not well discussed item is the fact that POEs with their inherent high viscosity index have a counterbalancing feature of having a low pressure viscosity index. When a low VI mineral oil is mechanically sqeezed between two low velocity metal surfaces the lubricant will increase viscosity and be very hard to push out from between the two surfaces. A high VI base will not thicken up as much under applied mechanical pressure and is more easily sqeezed out. Piston rings at top dead center have low velocity and may be under a lot of mechanical load - POEs will not hang in there as well as a mineral oil. When the rings are moving both lubricants will go back to hydrodynamic lubrication.

In refrigeration, POEs are a disaster in rotary vane compressors. The vane tips sqeeze the POE out from under them and cause rapid excessive wear. Mineral oils work much better. Anti-wear additives in POEs just don't do the job in that application, and it requires hardening the vane tip with nitride metal treatments to get the vane tip to survivie.

Esters like POEs are very good in some applications, but may not be the best choice in others. They do make interesting materials to formulate with, but are somewhat costly. If you need the benefits of esters, then you have no problem with the cost like in jet turbine engines and air / refrigeration compressors.

From here Another aritcle on Synthetics/Esters - Bob Is The Oil Guy