Running 0w30 instead of 5w20

[21Rouge]

Originally Posted By: DAB1123
My 2003 Pontiac Vibe specifies 5W-30, both in the manual & on the fill cap.


My 05 Vibe is spec'd identically and I am currently running 0W20. We shall see.

 

[cp3]

I would have to agree with the earlier post, in that I have read numerous times that using anything other than 5w20 will have and effect on the MDS.

The difference between 3.33cP and 3.06cP may not be a dramatic difference but it is a difference, especially for an engine designed to use something at 2.6cP. The higher the HTHS number the thicker the oil will be at operating temperatures and therefore generate higher oil pressure which in this case the MDS uses to operate. At least that's my take, CATERHAM may be able to explain it better!

As to the 10w30 post, it is my understanding that is only for the old design 3.5 which was apparently never spec'd for 5w20.

 

[Hokiefyd]

Yes (about the 10W-30 being spec'd for the 3.5L/4.0L V-6 engines), and the "new" Hemi calling for 5W-40 is probably the 6.1L version; it actually calls for 0W-40, and does NOT have MDS. My understanding is the MDS is especially sensitive to oil viscosity, and thusly, the 5W-20 "requirement".

 

[Bryanccfshr]

There are other factors on what makes 0/5w20's acceptable in engines. One being the ability of the cooling system to evenly cool the cylinder jackets. Uneven cooling in this and the head area can result in enough distortion in the cylinder bore that a higher viscosity must be recommended.
As far as the efficacy of the need for lighter oils to operate variable timing valve cam systems or a MDS system I have a little problem with that argument. I see these as hydraulic systems like a hydraulic lash adjuster, pressure is pressure.

A higher viscosity oil may be less efficient at operating this system(think of orifices the system has built in for oil return)but it may still operate but at a less than ideal activation/deactivation rate.

All said this is a systemic recommendation and although the system may be able to tolerate a wide range of viscosities the recommended viscosity is what works best for that engine to operate optimally.

 

[zpa]

I've always thought that HTHS visc indicates the ability to protect, and that it doesn't go hand in hand with kinematic visc? So two oils, say, both KV@100 10cSt would behave the same in a hydraulic system like MDS. Pressure depends on density and flow, right?

 

[NHHEMI]

Originally Posted By: gdragich
I have 5.7 Dodge with MDS system that requires 5w20. Have used the 0w20 before, but remembered someone on here talking about the 0w30 is pretty close to a 5w20 and thinking the slightly thicker oil may help with the infamous Hemi tick and yield a little more protection longterm.
Curious as to thoughts.


No, do not use 0W-30 in your MDS equipped Ram. Don't use anything but a 20 weight oil! Not only would it compromise any warranty you have( possibly a lifetime power train warranty depending on what year this is )but it will not allow MDS to operate properly. You can use 0W-20 if you wish but no 30, 40, or 50 weights.

MDS operates using oil pressure to activate special lifters. When the system is activated special solenoids( I believe they are under the intake )open allowing high pressure oil to travel through oil galleries to the MDS lifters. That oil hits a pin in the lifter and depresses it. This allows those lifters to collapse on themselves which is a crucial part of the MDS system. A 20 weight is required for that to all operate properly. Remember, at operating temp a 0W-30 is a 30 weight.

Stay with a 20 weight oil unless you buy a handheld tuner and disable MDS( warranty issues again but just saying.. ). In that case you can run a 0W/5W/10W-30 with no problems. Run a good synthetic if you have the tick and it will help some.

 

[NHHEMI]

Originally Posted By: Hokiefyd
Yes (about the 10W-30 being spec'd for the 3.5L/4.0L V-6 engines), and the "new" Hemi calling for 5W-40 is probably the 6.1L version; it actually calls for 0W-40, and does NOT have MDS. My understanding is the MDS is especially sensitive to oil viscosity, and thusly, the 5W-20 "requirement".


All correct. 10W-30 is only spec'd for 3.5L and 4.0L V6 engines not the HEMI with MDS( it was allowed for in 03 and 04 HEMI Rams used in temps above 0 degrees F just as a note ). No 5W-40 HEMI oil spec. It is 0W-40 and it is for the 6.1L which does not have MDS so right again. And you are also right that the MDS system is oil weight sensitive and requires a 20 weight( 5W is the spec but a 0W works ).

Excellent post!

 

[FZ1]

You're thinkin' too much. Run the oem spec weight oil. The Oem knows better than you,or,I what weight they want run in their truck. Look,within the 5-20 grade,for thincker/thinner oils. .02.

 

[CATERHAM]

Originally Posted By: zpa
I've always thought that HTHS visc indicates the ability to protect, and that it doesn't go hand in hand with kinematic visc? So two oils, say, both KV@100 10cSt would behave the same in a hydraulic system like MDS. Pressure depends on density and flow, right?

Actually you've got it backwards.
Oils with the same HTHS viscosity will have the same (operational) viscosity in an IC engine at normal operating temperature and above
regardless of what their KV100 spec's might be.
The following link explains in more detail:
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2022640&page=3

 

[shpankey]

If I were you, I would give castrol edge 5w20 (or 0w20 if u can find it) combined with a K&N oil filter and see if that helps the ticking. Edge is known to be a very quiet oil for loud engines. Something I can testify to myself.

 

[kcfx4]

+1 on the oil, ive not used k&n oil filter, but Bosch D+ and edge have been good for me

 

[CATERHAM]

Somewhat off topic, but for all the BITOGers using Edge 0W-20 or 5W-20 for that matter, we don't have a single UOA yet!

 

[FZ1]

Interested in trying the 5-20 Edge but the product data sheet indicates it is very thin,yet the pour point is not as low as the M1. Guess I'll stick with the M1 EP deals,for now.

 

[kcfx4]

it does seem to be thin

 

[demarpaint]

Originally Posted By: FZ1
Interested in trying the 5-20 Edge but the product data sheet indicates it is very thin,yet the pour point is not as low as the M1. Guess I'll stick with the M1 EP deals,for now.


Check out the 0W20, it is working quite well for me. It is a little "thicker" at 100C than the Edge 5W20 is.

 

[FZ1]

Thanks,D. I noticed that on the pds and thought it odd. Why would the 0 be thicker than the 5?

 

[CATERHAM]

Originally Posted By: demarpaint
Originally Posted By: FZ1
Interested in trying the 5-20 Edge but the product data sheet indicates it is very thin,yet the pour point is not as low as the M1. Guess I'll stick with the M1 EP deals,for now.


Check out the 0W20, it is working quite well for me. It is a little "thicker" at 100C than the Edge 5W20 is.

A common BITOG misconception.
A higher KV100 spec' doesn't necessarily mean the oil is any "thicker" in terms of operational viscosity unless it has a higher HTHS viscosity. If it doesn't, and in the case of Edge 0W-20 and 5W-20, they are likely the same at 2.6cP, then the two oils will have the same viscosity at operating temperature, at least in their virginal state.
But the 0W-20 has an unprecedentedly high VI at 220 vs 175 for the 5W-20, consiquently it is likely less shear stable and therefore actually lighter in actual service.

 

[demarpaint]

Originally Posted By: CATERHAM
Originally Posted By: demarpaint
Originally Posted By: FZ1
Interested in trying the 5-20 Edge but the product data sheet indicates it is very thin,yet the pour point is not as low as the M1. Guess I'll stick with the M1 EP deals,for now.


Check out the 0W20, it is working quite well for me. It is a little "thicker" at 100C than the Edge 5W20 is.

A common BITOG misconception.
A higher KV100 spec' doesn't necessarily mean the oil is any "thicker" in terms of operational viscosity unless it has a higher HTHS viscosity. If it doesn't, and in the case of Edge 0W-20 and 5W-20, they are likely the same at 2.6cP, then the two oils will have the same viscosity at operating temperature, at least in their virginal state.
But the 0W-20 has an unprecedentedly high VI at 220 vs 175 for the 5W-20, consiquently it is likely less shear stable and therefore actually lighter in actual service.


The info I stated was from a conversation I had quite a while back with a Castrol rep re: 0W20 and 5W20 Edge. You are correct about the unprecedentedly high VI @ 220C for the 0W20. But according to the person I spoke with it is the "unique" formula that 0W20 Edge has that makes it slightly "thicker" than the 5W20 at operating temps. It also will not shear out of grade, and is well within the specs of a 20 grade oil.

Go easy on my I'm not a scientist nor a chemist, I'm repeating what I was told. It could be a bunch of [censored] but at the time it seemed like the person was telling the truth within the boundaries of what they could say. They both perform very well in applications approved for 20 grade oils was another comment, with two thumbs up for the 0W20 for cold starts and cold weather applications and in hybrid engines.

When asked if a 30 grade oil would protect better than a 20 grade oil, or if it can be used in place of a 20 grade oil, I got the usual reply. Use only what the mfg suggests for your climate and application. LOL Which is exactly what I expected to hear.

 

[Boss302fan]

a 30 weight oil will work fine in your application... Edge or Mobil 1 EP would be very good oils to use.

 

[CATERHAM]

Hi demarpaint,

I wish when you were talking to Castrol you asked what the HTHS vis was of the two oils, it's certainly not proprietary info'; that lack of HTHS viscosity info' is one of the most annoying things about Castrol.

What is not true or is an indication the rep' is not well informed, is the comment that "it will not shear out of grade, and is well within the specs of a 20 grade oil".
Their 0W-20 oil is clearly targeted at the Japanese OEM 0W-20 oils that meet the requirements of Toyota and Honda and part of the requirement is having a HTHS vis no higher than 2.6cP. The Nippon Oil supplied Toyota oil, which I'm familiar with does shear out grade by design close to 10% almost immediately once put into service. The HTHS vis drops to somewhere in the 2.35-2.40cP range which technically means it is no longer a 20wt oil if it was being judge as a virgin product. The SAE grading system allows something like 15% shear so technically an oil can drop below the minimum 2.6cP spec' and still be considered a 20 wt oil. It's kinematic viscosity will still be around 8.0cSt (still at the high end of a 20wt range) but that is not the true measure of an oil's operational viscosity, the HTHS vis' is.

We have yet to see a UOA of Castrol's 0W-20, but when we do I expect to see about 10% shear in even the shortest OCI; again by design.