Opinions or knowledge concerning Mobil 0w-30?

Status
Not open for further replies.
Joined
Mar 3, 2007
Messages
55
Location
Colorado
Hi,

First off this forum is great. I'm quickly becoming a serious oil nerd, mainly in the quest for more knowledge on the topic. As an auto technician I like to have answers for everything car related, and lubricants are one area where I'm lacking.

Now to my question. I did a cursory search for info on Mobil 1 0w-30, and found nothing. Maybe I need to get used to this search engine, whatever. Sorry if this is a dead subject.

I want to know if there is anything that should scare me away from the oil. I could use "GC" Castrol, I suppose, but Mobil is cheap around here. I've been reading a lot about the 0w-40 and it seems like they use a lot of viscosity index improvers to get this rating, which bugs me from a technical standpoint; do they do the same for the 0w30 or do they rely more on the nature of the base stock for this rating?

Thanks for the input.

Ringe
 
BTW, my car is a Subaru WRX, EJ25 motor. Any specific recommendations for this car appreciated.
 
Hello. To get a rough idea of the amount of viscosity index improvers, calculate KV@100C/HTHS. The higher the number, generally the greater the amount of viscosity index improvers.
 
Originally Posted By: JAG
Hello. To get a rough idea of the amount of viscosity index improvers, calculate KV@100C/HTHS. The higher the number, generally the greater the amount of viscosity index improvers.


Sorry, what is HTHS?
 
Nevermind, I think I found that out.

So, based on the info from Mobil.com the oil has a Kinematic viscosity of 11.0 at 100*C, and an HTHS viscosity of 2.99 at 150*C. So, the 11.0/2.99 would be 3.67. Would that be high or low?
 
High-Temperature-High-Shear-Viscosity. It's on some oils' Product Data Sheets, including Mobil 1 oils. It is a much better measure of the relevent viscosity of oil in an fully warmed up engine than is KV@100C.

I just saw you found it while I posted. The Mobil 1 0w30 ratio you calculated is semi-high. Once you calculate it for a lot of different oils of widely ranging properties, you'll get a feel for the range.
 
Last edited:
Thank you!

So tell me, am I wrong in considering a high VII percentage to be less than perfect?

(Sorry to bury you in questions! haha...)
 
A super high VII oil achieved with heavy doses of polymers has its weaknesses and strengths. It's a compromise formulation. The application should dictate what would be best. Although I've used Mobil 1 0W-40 many times, it wasn't because I wanted a 0W oil. In contrast I'm now using Amsoil ACD SAE 30/10W-30 which has zero polymeric viscosity index improvers. That's two ends of the spectrum from that standpoint.

I'm not a Subaru guru anymore but there are some here so hopefully they'll help you on the practical matter of what viscometric properties may work best in your engine and driving habits. What is your climate like and what are your driving habits?
 
Originally Posted By: JAG
A super high VII oil achieved with heavy doses of polymers has its weaknesses and strengths. It's a compromise formulation. The application should dictate what would be best. Although I've used Mobil 1 0W-40 many times, it wasn't because I wanted a 0W oil. In contrast I'm now using Amsoil ACD SAE 30/10W-30 which has zero polymeric viscosity index improvers. That's two ends of the spectrum from that standpoint.

I'm not a Subaru guru anymore but there are some here so hopefully they'll help you on the practical matter of what viscometric properties may work best in your engine and driving habits. What is your climate like and what are your driving habits?


The climate is mild; winter lows usually no less than 0F, summer highs in the low to mid 90s, hardly ever above 100F.

My driving style is mechanically sympathetic. I like to drive the car hard occasionally, but my sense of caution rules the day for the most part, with RPM rarely crossing 4,000. Driving is a combination of city commuting and frequent long highway drives in the mountains. Engine reaches normal operating temp each drive, but I just installed an oil temp guage so I don't know how hot the oil gets on my commute. (Only about 3 miles, so probably not very hot).

I'm also changing the oil every 3750 while under warranty just to keep Subaru off my back in case something breaks, so I'd more than likely never see the drawback of these VIIs breaking down. After the warranty period I would base oil change intervals on UOA results, which I think I will start tracking shortly, just for the fun of it.
 
Mobil 1 0w30 is good oil. Hard to find around here for some reason.
Not a volume mover, I guess. If I can't buy it at Wal-mart or W/M prices, I don't get it.
I'd use it if I could find some.
If you don't go below 0°, why not stick with 5w30?
 
I'd buy it instead of 5w30 if they sold it in the big jugs. I like big jugs, especially since you can dump in the used oil and dead flies from the drain pan after you're finished changing.
 
Originally Posted By: dwendt44
Mobil 1 0w30 is good oil. Hard to find around here for some reason.
Not a volume mover, I guess. If I can't buy it at Wal-mart or W/M prices, I don't get it.
I'd use it if I could find some.
If you don't go below 0°, why not stick with 5w30?


Because even the 5w30 is a little thick for me some mornings. Or at least the engine seems to not dig it too much. Besides, the better cold flow I can get in any situation is better, isn't it?
 
Look for a new bottle and name for the 0w20 and 0w30 soon. These are their most "fuel efficienty" oils XOM makes.
 
I think it's a high quality product, in some ways the best XOM product, but it's just not that thin at the near-sub-zero temps I encounter. Pennzoil Platinum 5w30 better in that respect and the Pennzoil Platinum 5w-20...
 
Originally Posted By: JAG
Hello. To get a rough idea of the amount of viscosity index improvers, calculate KV@100C/HTHS. The higher the number, generally the greater the amount of viscosity index improvers.
Where does this come from? Just curious.
 
Iceberg, that formula makes use of the fact that polymeric viscosity index improvers boost the kinematic viscosity at 100C much more than they do the HTHS at 150C. That is mostly because they make the motor oil a shear thinning fluid as opposed to a Newtonian fluid. Basically the faster you make it flow, the more the viscosity decreases. The shear thinning refers to temporary shear thinning which results from the polymers aligning themselves when the oil is "squeezed" at a high enough shear rate. When the stress is removed, the polymers can go back to their natural bulky shape. Temporary shear thinning happens in non-Newtonian fluids immediately on a virgin oil, given sufficient shear rate...3000 miles or whatever mileage or time is not needed.

Permanent shear thinning refers to when they break apart and can't reform. That shows up in the kinematic viscosity measurement.
 
Originally Posted By: dailydriver
The Mobil 1R is a separate XOM product from this 0W-30??

Yes it is...and I don't believe Mobil still makes the Mobil 1 0w30 "racing" version. You may still find some old-stock out there somewhere though.
 
Status
Not open for further replies.
Back
Top Bottom