Cold Start Thickness - Dr. Haas

[ADFD1]

Great debate. I think what Dr.Haas is saying is this. It's not if oil is flowing or not, we all know as soon as the engine sparks to life oil is flowing, the problem is it is not protecting 100% until it gets to that desired #10. I think that it what the Dr is trying to say. The engine certainly isn't grinding itself to death, it just isn't getting optimum protection until 100*C. The 0W oils get to that number 10 faster, that is the point of his discussion? I wish he'd weigh in.

Again my opinion and interpretation of that section of his writings. BTW if you speak with Redline, Mobil or any of the oil companies, they will tell you the best protection occurs when the oil is at the desired temperature, and most wear occurs while it is getting there. We tend to think that the engine is grinding away while we wait, the wear is very slight, but occurring. Again my view on what I've read and heard from talking with various people. The 0W-xx is protecting better from the get go, that has been told to me from just about every oil company I've chatted with.

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[Zaedock]

Originally Posted By: BuickGN
What do you people think, an engine sits there and grinds metal to metal until the oil warms up?


This is the best quote I have ever heard!

I'll still be driving my Jeep on SAE30 and 10W40 long after some of these people's next car, they haven't even bought yet, dies.


Still, I do commend the good doctor on his information and research. I may not agree with all of it, but it still offers some great insight. ...and I still run 5W20 in my truck (QS dino even!).
I think Bill hit the nail on the head once when he said it was more important to change your oil than what oil you're using. I also think that every engine is different and responds to various oils with various results. Dino vs. Syn isn't cut & dry. Neither is thin vs. thick. Find what works best in your application and enjoy your vehicle.

 

[Taylor]

He's not saying it's geting there faster, he is saying is closer to begin with. The oils probably reach 100*c at the same rate, or maybe not maybe density plays a role in this rate?

The point Gary, and Buick are making (correct me if I'm wrong) is that there are many other variables that contribute to the wear. i.e. thermal expansion of the motor, whether or not the additives are thermally activated, etc.

Buick, I agree some of Dr. Haas's statements are bold! Does a 0w50 have no VII's? Another thing to consider is the base-oils natural VI, some of the higher quallity straight weights out flow lower quality multi-grades. Amsoil ACD come to mind, as well as RL's racing line, and I believe this is what DR. Haas what refering to.

Everyone who picks a 0wX over 5wX 10wX 15wX 20wX without second thought needs to check out a couple specs before jumpng to a decision.
1.) HTHS
2.) NOACK
3.) Flashpoint
Now don't get me wrong I tend to choose thin over thick, but when recently choosing between a 0w40 and a 5w40 I went with the 5w40 for mainly these reasons.

 

[jigen]

Originally Posted By: BuickGN
Actually to clarify, I would have no problem using a 0w-20 over a 5w-20. I would still prefer a 10w-30 over a 5w-30.


As a newbie may I ask why?

 

[Nickdfresh]

Originally Posted By: Gary Allan
...
In the fine doctor's cited references, the acclaimed Schneider measured cylinder:ring wear during the warm up event. It forms a curve of decreasing wear as you approach full warm up.

One cannot attribute this curve to viscosity...


Exactly...

 

[Taylor]

Also I believe reducing the amount of time it takes for the motor to warm can only help. And pre-heating your oil can only help, especially if additives are indeed thermally activated. Doing this would also allow the use of a straight weight, and therefore eliminate the questions in this debate. But the previously mentioned variables still exist. So couple that with a block heater, and in theroy the warm up time is significantly reduced. Maybe throw in a pre-oiler for good measure? Now im just rambling...

 

[ADFD1]

All good points and they would certainly help reduce engine wear.

I think what Dr. Haas is saying is if its closer to 10 its still protecting better, and will probably get there sooner? Can anyone prove or disprove this? In layman's terms what he is saying makes sense? I do agree there are many other factors, but the closer you start to that perfect 10 the better, especially in colder weather. Rambling myself here.

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[Taylor]

Again I don't know if he's necessarily saying it gets there faster, I think he's saying it's closer to begin with.

For ex. if you take a 0w30 and a 10w30 at 40*C they are a "0w" and "10w" respectively. But it *probably* takes the same amount of time to reach a 30w, or 100*C. Not sure if that is correct or not, if not I'm not sure what factors affect this. Maybe density? IDK!

 

[Gary Allan]

The main thing to keep in mind is that the "90% of wear that occurs at start up" (the first 20 minutes, on average) is mostly unavoidable. You may alter it by a standard deviation or two up or down ..but you're still (most likely) left with the majority of it.

You can warm oil and coolant to operating temperatures. This will somewhat shorten the start up (warm up) event, but probably not as much as one might think. The combustion process cannot be simulated by merely duplicating its effects on oil and coolant. You're not blowing combustion temp air through the combustion chambers and all the rest of it.

To give you an idea of what my observations showed in monitoring oil temps, the ambient temp didn't really alter the "time to normalization". It still took the same 13 miles +/- and the curve was pretty much the same. The curve is not linear ..but the profile/contour stayed pretty much the same. Just the temp varied +/-10f at x-mileage/time. Keep in mind that to a piston, the difference between 15F and 85F doesn't mean all that much when it may have a normalized temp that's kept the solid side of molten only by the cooling employed. Only the btu's blasting through the cooling medium changes.

 

[BuickGN]

Originally Posted By: Taylor
Again I don't know if he's necessarily saying it gets there faster, I think he's saying it's closer to begin with.

For ex. if you take a 0w30 and a 10w30 at 40*C they are a "0w" and "10w" respectively. But it *probably* takes the same amount of time to reach a 30w, or 100*C. Not sure if that is correct or not, if not I'm not sure what factors affect this. Maybe density? IDK!



You are correct, at least from my experiences with an oil temperature guage and running different weights. No noticable difference in time to fully warm though I've never acutally timed it.

 

[BuickGN]

Originally Posted By: ADFD1
All good points and they would certainly help reduce engine wear.

I think what Dr. Haas is saying is if its closer to 10 its still protecting better, and will probably get there sooner? Can anyone prove or disprove this? In layman's terms what he is saying makes sense? I do agree there are many other factors, but the closer you start to that perfect 10 the better, especially in colder weather. Rambling myself here.

AD


As long as it's the correct viscosity for the temperatures, you can't tell the difference in the time to pressure and flow between a light oil and a thicker oil.

For example my TL going from a 5w-20 to a straight 30. My GN going from a 10w-30 to a 20w-50. I pay close attention to the idiot light and mechanical oil prssure guage. I've paid attention to flow from the valvetrain and turbo. If there is a difference it's not enough to tell with the human eye.

Now if you had a 20w-50 in a -20 cold start you would probably have issues with time to pressure.

 

[BuickGN]

Originally Posted By: jigen
Originally Posted By: BuickGN
Actually to clarify, I would have no problem using a 0w-20 over a 5w-20. I would still prefer a 10w-30 over a 5w-30.


As a newbie may I ask why?


The smaller spread in numbers, the less likely it is to shear....all things being equal which they sometimes aren't.

 

[Art_Vandelay]

Originally Posted By: Gary Allan
The main thing to keep in mind is that the "90% of wear that occurs at start up" (the first 20 minutes, on average) is mostly unavoidable.


Would you say that a straight 30 weight and a 5W-30 exhibit the same wear characteristics during this 20 minute start up cycle?

Suppose an ambient temperature of 75F for this question.

 

[ADFD1]

I'd go with the 5W30 for the first 20 minutes.

AD

 

[BuickGN]

Originally Posted By: ADFD1
I'd go with the 5W30 for the first 20 minutes.

AD


And how much personal experience do you have with the straight 30? I've used both and I'm telling you there's no difference in time to pressure and flow.

What other reason would you have besides pressure and flow? All I can come up with is mpg during the warmup cycle.

Did you ever see the test on cylinder bore wear using a straight 30 vs multi-grades? The straight weight showed less wear.

 

[Taylor]

I know there are many more variables than solely viscosity, but theoreticaly wouldn't a thinner oil keep the pump out of bypass more. As well as have less strain on the pump being easier to move. In turn reducing load on the camshaft, a load that actually helps with harmonics??

 

[Taylor]

Originally Posted By: BuickGN
Originally Posted By: ADFD1
I'd go with the 5W30 for the first 20 minutes.

AD


And how much personal experience do you have with the straight 30? I've used both and I'm telling you there's no difference in time to pressure and flow.

What other reason would you have besides pressure and flow? All I can come up with is mpg during the warmup cycle.

Did you ever see the test on cylinder bore wear using a straight 30 vs multi-grades? The straight weight showed less wear.


I'm not doubting this, but do you have a link?

 

[ADFD1]

Originally Posted By: BuickGN
Originally Posted By: ADFD1
I'd go with the 5W30 for the first 20 minutes.

AD


And how much personal experience do you have with the straight 30? I've used both and I'm telling you there's no difference in time to pressure and flow.

What other reason would you have besides pressure and flow? All I can come up with is mpg during the warmup cycle.

Did you ever see the test on cylinder bore wear using a straight 30 vs multi-grades? The straight weight showed less wear.


Pressure and flow for starters, better startup protection, less fuel consumption, better in the cold, better for the first start of the day. IMO if the straight grade oils were so much better they'd have more shelf space in the stores. I'm speaking about passenger cars, not HP applications where a straight grade oil would probably be better.

I'd like to see that link too. Thanks


AD

 

[Art_Vandelay]

Originally Posted By: BuickGN

The smaller spread in numbers, the less likely it is to shear.


I'm sure that is true. Except for the case of some 0W-30 oils specifically GC. It is more shear stable than any 5W-30 made. I wonder if that is just a consequence of very high PAO content?

 

[Taylor]

There are many straight weight oils that "out flow" (lower pour point, thinner viscosity @ 40*C) multi-grades, due to the base oils natural viscosity index. Check out Amsoil ACD for example.