SAE 30

[mva]

Originally Posted By: KA426
I've run Pennzoil SAE 30 in many of my automobiles in the summertime. It's good oil. Use it in the lawnmower too.


Looking at Pennzoil's spec sheets for SAE 30:

Pour point -30C

Viscosity @40C = 98 cSt

Viscosity @100C = 11.5 cSt

Pretty good cold performance - I would call it a 15W30.

 

[Zaedock]

Originally Posted By: gfh77665
I noticed you didn't answer why we have multi-vis oils in the first place...

But, OK, my friend. If you somehow really believe that 30 flows just as fast as 5-20, carry on!


(PS: all I did was originally attempt to answer someones question. Thats what "open forums" are. I didn't want or need an argument with anyone.)


First, this thread isn't about why we need multi-visc oils. It's about SAE30. I never said we didn't need multi-visc oils. Nor do I believe that SAE30 flows "as fast" as 5W20. Frankly, it doesn't need to. "It flows" and gets to where it needs to be, (as the engine is cranking) before it starts. That's what matters. Obviously, SAE30 is not ideal for below freezing conditions.

I'm not here to argue either, but you open yourself up for argument when you state that running SAE30 causes metal to metal contact for several seconds until it flows. That is not correct.

 

[lexus114]

why the heck would you want to use a lawnmower oil in your car??

 

[drivewaytech]

I knew a guy that drove his riding lawnmower to the Quicky Mart that's 1 mile up the road a lot. He got a DUI last summer, or would it MUI (Mowing under the influence).

I wonder how well SAE 30 would perform in a 5W-20 spec'd vehicle during warm seasons.

 

[Jaymus]

Originally Posted By: mva
Looking at Pennzoil's spec sheets for SAE 30:

Pour point -30C

Viscosity @40C = 98 cSt

Viscosity @100C = 11.5 cSt

Pretty good cold performance - I would call it a 15W30.


Wow, that's good numbers for a straight 30. Kind of makes me mad about my Rotella Synthetic 5W-40. It is 95cst @ 40C/15.5cst @ 100C. Mobil1 TDT 5W-40 is 100.4cst @ 40C/14.9 @ 100C

I didn't think a straight 30 would have a cold weight of a 5W-40.

 

[Jaymus]

I can't edit, but I want to say I have looked into more 5W-40's (which tend to be HDEO's). Then I looked up 15W-40 Rotella-T. Its cst @ 100C was 15.7, and 118cst @ 40C. That's not far off from either 5W-40 Mobil1 TDT or synthetic Rotella. I figured the 40C viscosity would have been lower for the synthetic.

 

[BuickGN]

Originally Posted By: drivewaytech
I knew a guy that drove his riding lawnmower to the Quicky Mart that's 1 mile up the road a lot. He got a DUI last summer, or would it MUI (Mowing under the influence).

I wonder how well SAE 30 would perform in a 5W-20 spec'd vehicle during warm seasons.


Been doing that for over 2 years, year round.

This board made me so fearful even though I knew it would work that before I did the switch I started paying close attention to how long it took the idiot light to go off and a few times I had the girlfirend crank the car over for it's first start of the day with me looking through the oil fill hole to get a feel for how long it took oil to start flowing up there which turned out to be before she released the key.

Did the same with the straight 30 and there's no percievable difference. In a climate where 30 is recommended, the difference in time to pressure and time to upper valvetrain flow is not measureable. Do the same tests in -20 weather and I'm sure the mulit-vis oils would shine.

Edit: And to those of you who think it takes 5-10 seconds to get pressure, you're dead wrong. It's pretty much instant.

The ACD that I use is only 66cst@40.

 

[XS650]

Originally Posted By: mva
Originally Posted By: KA426
I've run Pennzoil SAE 30 in many of my automobiles in the summertime. It's good oil. Use it in the lawnmower too.


Looking at Pennzoil's spec sheets for SAE 30:

Pour point -30C

Viscosity @40C = 98 cSt

Viscosity @100C = 11.5 cSt

Pretty good cold performance - I would call it a 15W30.


Many if not most straight 30 weight could be called an xW-30 if the manufacturer qualified them as such. Problem then would be that people who insist on a straight 30 weight wouldn't want to buy it

As of about 10 years ago (prolly hasn't changed), if a manufacturer didn't go for xW qualification on an oil, they could call it a straight vis oil no matter how good it's low temp performance was. However, onece the manufacturer does go for and xW qualification, they can't call it anything other than what it tests out to be.

You could call a 0W-30 oil a straight 30 if you skipped the qualification process, but it you test an oil and it comes out 5W-30, you can't call it a 10W-30.

The above only applies to API approved oils.

 

[zoomzoom]

what I am curious about is what is the viscosity of straight weight 30 at say 0C,-10C and -20C when compared with 5w-30 or 0w-30 oil

so for example can someone calculate side by side viscosity for
Amsoil ACD SAE 30 VS GC 0W-30 for:
40C
30C
20C
10C
0C
-10C
-20C
-30C

 

[XS650]

You can't just calculate it, you need to measure it at at least two well separated temperatures to establish the viscosity index, then you can do some calculations.

The 40C and 100C data points aren't very good for calculating sub zero viscosities.

 

[zoomzoom]

so ACD is
66.3 cSt @40C
10.5 cSt @100C
VI 141

GC is:
72.2 cSt @40
12.2 cSt @100
VI 167

can anyone plug these in viscosity calculator and get their corresponding viscosity for these temperatures?
40C
30C
20C
10C
0C
-10C
-20C
-30C

 

[zoomzoom]

here what I got using viscosity calculator:
http://www.truckersoilforum.com/vicalc/VI.htm

Looking at the chart there is very little difference between GC and ACD 30 until you get to about -10C where split in viscosity becomes evident,however even at -20C difference is not drastic.

So you could run ACD safely down to -20C/-4F

 

[AndyH]

Originally Posted By: oilyriser
Subaru 2001 Legacy manual recommends #30 or #40 for severe conditions like desert driving or towing.

As does my 2005 Subaru owner's manual:.

 

[zoomzoom]

Redline 5W-30 does even better then GC, you can clearly see that Redline 10W-30 is actually 30 weight oil very similar to AMSOIL ACD.

Looking at these graph one could conclude that there is no real advantage running multigrade oil over straight grade synthetic oil unless you see lot of starts below -15/20C

 

[XS650]

Zoomzoom,

Extrapolating viscosity below 0C using 40C and 100C data is questionable at best.

 

[zoomzoom]

I used 40C and 100C viscosity with viscosity index of each oil, shouldn't that give accurate results?

What is better way to create these charts?

 

[jmac]

Originally Posted By: zoomzoom
I used 40C and 100C viscosity with viscosity index of each oil, shouldn't that give accurate results?

What is better way to create these charts?


question 1, No

Question 2, Measurement

 

[zoomzoom]

so these viscosity calculators are useless?

 

[fsskier]

Cold Start/Cold wear: I am suprised so many think that lubrication occurs just because there is oil pressure.

Yes, the bearings have oil. They had oil all night, and receive pressure immediately. The cylinder walls only get what flys off the rod bearings, and the tiny little squirter hold on the top of the rod big end. Rod bearings typically having .002 inch of clearance, nearly no 30 W oil flows through them cold. Try loosening up the top of your oil bottle .002 and filling your crankcase with cold oil. Similarly MANY seconds elapse between each drop of oil flying off the rod bearing to possibly fly unto the cylinder wall, but more likely flying downward, sideways, or perhaps straight up into the center of the piston.
Now, imagine that same bearing when hot or thin oil is flowing, a virtual shower of oil flys onto the wall and the piston is hydroplaning with virtually no wear.

When GM was switching from 10W40 to 5W30 in the early 80's
they published (in the SAE journal) the results of their multi million dollar lubrication studym they claimed that this change alone would increase engine life nearly 30 percent, assuming a 5 degree F start.

Ford, in an attempt to save money, started not putting the extra drill hole in the rod bearing (big end) from 1974 to 1977. As our older Bitogers know, this resulted in massive failures in the northern states of extreme cylinder wall wear, motors shot by 30-40 k miles. Among my small work group Ford paid for:
two Pinto 2300 CC motors, 1 Maverick 200 Cu in 6 and one Lincoln Continental. Make note that all these engines would have had oil pressure immediately, and the owners that had gauges noticed that they had LESS PRESSURE after the new rods were installed.
PRESSURE IS NOT FLOW!!!!!!

This problem did not occur in the southern states. Now look at the curves above and tell me why we would want such thick oil at colder temperatures??? Then why not run straight 80 W when hot if so much pressure is good and flow is not important??

 

[Zaedock]

Originally Posted By: fsskier
Rod bearings typically having .002 inch of clearance, nearly no 30 W oil flows through them cold. Try loosening up the top of your oil bottle .002 and filling your crankcase with cold oil.


If you could squeeze the bottle with several thousand PSI of pressure, like hydrodynamic engine bearings, you'd get plenty of oil out of that bottle. Even cold.