20wt oils, higher temperatures and oil coolers

[Garak]

Originally Posted By: StevieC
I know but I worry at those higher temperatures that the timing chain and guides could be prematurely wearing and I wan't my 500,000km

When you're warranty is over, switch to an A3/B4 if you're concerned, like zeng suggested.

Or play with an oil cooler then, too.

 

[StevieC]

Chrysler warranty is 4 years, 60,000km or 10ft or how the dealer is feeling that day. It's been up for a bit now.

 

[Garak]

Then you have all the options in the world.

 

[StevieC]

I do, I do... It's why I posted here about it...

 

[zeng]

Originally Posted By: StevieC
I did try the 30wt version of SSO and saw almost no decrease in temperature. My mom runs conventional 5w30 and same thing... It's just a poor design in my opinion.

I got your point.
But for almost same purchase price, at similar operating temperature your engine gains higher MOFT in xW30 than a xW20, hence a higher margin of engine protection.

 

[StevieC]

Oh I see now...

 

[zeng]

Originally Posted By: zeng
Originally Posted By: StevieC
I did try the 30wt version of SSO and saw almost no decrease in temperature. My mom runs conventional 5w30 and same thing... It's just a poor design in my opinion.

I got your point.
But for almost same purchase price, at similar operating temperature your engine gains higher MOFT in xW30 than a xW20, hence a higher margin of engine protection.


Missing out windows for editing.
With Wizman ,comparing Amsoil SS 5W20 against SS 5W30 :-


....and comparing their operating viscosities at varying tempetatures :-


... At 120*C,a thinner oil in 5W20 operates at 6.0 cSt .
A thicker oil in 5W30 gives you 7.0 cSt, and stays thicker at higher operating temperatures upto 129*C .....
hence thicker oil always without fail, provides higher margin of protection than a thinner oil, a 5W20 @ 120*C in your case.

 

[ZeeOSix]

Originally Posted By: zeng
...and comparing their operating viscosities at varying tempetatures :-


Another way to interpret the comparison is the 5W-30 gived 8~10 deg C of operating temperature advantage/headroom. Not huge, but it could make a difference if near the limit of a dangerously thin MOFT with the 5W-20.

To get more MOFT safety margin, like in a race car use senario, you'd go for something like a 5W-50 like GM and Ford recommend im their hi-pro vehicled during track use.

A 5W-20 or 5W-30 could be ran in a race car if it had good enough oil coolers to keep the oil temperature down to a safe level.

 

[StevieC]

Wasn't there a guy on BITOG that had some exotic car that called for 60wt but he was running a thinner weight? I forget the guys name.

 

[4WD]

AE Haas?

 

[zeng]

Originally Posted By: 4WD
AE Haas?

... from whom I was expecting an xW20 UOA of reasonable OCI from his Porsche to prove his 'xW20' point.
But, no luck todate.

 

[StevieC]

I think that was him... He's a doctor?

 

[StevieC]

I think that was him... He's a doctor?

 

[Virtus_Probi]

Originally Posted By: ZeeOSix
Originally Posted By: zeng
...and comparing their operating viscosities at varying tempetatures :-


Another way to interpret the comparison is the 5W-30 gived 8~10 deg C of operating temperature advantage/headroom. Not huge, but it could make a difference if near the limit of a dangerously thin MOFT with the 5W-20.

To get more MOFT safety margin, like in a race car use senario, you'd go for something like a 5W-50 like GM and Ford recommend im their hi-pro vehicled during track use.

A 5W-20 or 5W-30 could be ran in a race car if it had good enough oil coolers to keep the oil temperature down to a safe level.


The only mitigating factor is that the thicker oil will, itself, be a bit hotter than the thinner one given the exact same engine conditions.
But, when I raised a question on this topic earlier, Shannow assured us that the resulting temperature difference can never be large enough for the two oils to switch places in viscosity and MOFT. This topic is right in his wheelhouse and I trust his statement implicitly, especially since it just plain makes sense to me.

 

[zeng]

Originally Posted By: Virtus_Probi
The only mitigating factor is that the thicker oil will, itself, be a bit hotter than the thinner one given the exact same engine conditions.......

Not true in this context , as per previous response from OP
Originally Posted By: StevieC
I actually saw a few degrees cooler.......


Edit:In harsh operating conditions, hydrodynamic drag losses may be of lesser significance than other losses.

 

[CT8]

Originally Posted By: StevieC
Wasn't there a guy on BITOG that had some exotic car that called for 60wt but he was running a thinner weight? I forget the guys name.
Driving an exotic to the mall doesn't produce lots on heat and Dr Hass doesn't seem to keep the cars a long time. His writings fooled lots of the sheep on several websites.

 

[Garak]

Originally Posted By: StevieC
I do, I do... It's why I posted here about it...

Well, if it were me, and I were worried - that's not to say you should be worried at all, but that's what we do here - I'd simply jump a grade, or even to something A3/B4. Sure, that won't lower the oil temperatures, but if you're not in limp mode already, it shouldn't make a difference. If you're worried about phosphorus content in an A3/B4, which doesn't worry me, you could always go to Shell Rotella T6 Multi-Vehicle 5w-30 or Delvac 1 LE 5w-30, both of which have the elevated HTHS for the HDEO ratings, but reduced phosphorus because of E6.

 

[Virtus_Probi]

Originally Posted By: zeng
Originally Posted By: Virtus_Probi
The only mitigating factor is that the thicker oil will, itself, be a bit hotter than the thinner one given the exact same engine conditions.......

Not true in this context , as per previous response from OP
Originally Posted By: StevieC
I actually saw a few degrees cooler.......

Edit:In harsh operating conditions, hydrodynamic drag losses may be of lesser significance than other losses.


I can't track down the thread from a year or more ago where this was discussed in some detail...it maybe have been mutilated beyond recognition by the change at a major picture hosting site not too long ago (which has destroyed a lot of really good old posts by Shannow).
I still think that the thicker (at a given temp) oil must run a bit hotter than a thinner oil under the same engine conditions IF they have the same specific heat capacity...and, I honestly have no idea how that property might vary amongst our oils.
I saw StevieC's earlier post and certainly don't think he's lying, but can only suspect that the operating conditions were a bit different in the two cases...but would love to hear if a real oil expert has a better explanation related to the properties of the oils involved.

 

[Garak]

Given Canada's climate conditions, lots of weird things can be seen with various vehicle temperatures across different applications.

 

[ZeeOSix]

Originally Posted By: Virtus_Probi
But, when I raised a question on this topic earlier, Shannow assured us that the resulting temperature difference can never be large enough for the two oils to switch places in viscosity and MOFT.

I agree that the increase in MOFT will out run the increase in oil temperature rise from shearing under the same engine operating conditions. If that wasn't true then Ford, GM, etc would never recommend using 5W-50 for extreme track use.