Which oil gets up to the operating temperature faster-RESULTS!!

[zoomzoom]

Backround:
I propose little experiment. Right now in my car I have delvac 15w40 which is about to be changed to GC 0W-30...Since I have oil temperature gauge I will make 6 data points( take a note of the time and distance it takes to get to op temp) with this oil and then do the same with GC.
This will be on my commute to and from work. I will try to leave at same time and drive in similar fashion.

Link to original discussion:
http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=1;t=011178;p=1

So results are here..It seems that thicker oil on average did got up to operating temp faster then thiner GC...But it is very close...

What is your take on these results?

Car is 2001 Audi S4 2.7L V6 BiTurbo

Oil is GC 0W-30

code:

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Outside Temp. *** 79 *** 83 *** 76 *** 83 *** 79 *** 81 ***

Time to 200F *** 14 *** 12 *** 13 *** 13 *** 15 *** 12 ***

Miles to 200F *** 5.2 *** 7.4 *** 7 *** 6.9 *** 7.5 *** 8 ***

Avg. Speed *** 34 *** 32 *** 40 *** 35 *** 38 *** 24 ***

Avg. MPG *** 27.8 *** 27.1 *** 27.5 *** 27.3 *** 27.8 *** 22.4 ***

Final Oil Temp *** 208 *** 206 *** 210 *** 205 *** 205 *** 210 ***

Total Drive Time *** 30 *** 32 *** 25 *** 28 *** 27 *** 42 ***

AC Used *** no *** no *** no *** no *** no *** no ***



Oil is Delvac 15w40



Outside Temp. *** 76 *** 86 *** 75 *** 88 *** 76 *** 89 ***

Time to 200F *** 12 *** 11 *** 14 *** 11 *** 12 *** 9 ***

Miles to 200F *** 8 *** 7.2 *** 8.5 *** 5.9 *** 6 *** 6.4 ***

Avg. Speed *** 40 *** 35 *** 40 *** 37 *** 42 *** 35 ***

Avg. MPG *** 28.4 *** 27.3 *** 27.8 *** 25.1 *** 27.7 *** 25.1 ***

Final Oil Temp *** 212 *** 210 *** 215 *** 212 *** 212 *** 212 ***

Total Drive Time *** 25 *** 28 *** 25 *** 28 *** 24 *** 30 ***

AC Used *** no *** no *** no *** yes *** no *** no ***



now the averages:



Oil Used *** 0w30 *** 15w40 ***

Outside Temp. *** 80.2 *** 80.2 ***

Time to 200F *** 13.2 *** 12 ***

Miles to 200F *** 7.0 *** 7.12 ***

Avg. Speed *** 33.8 *** 38.8 ***

Avg. MPG *** 26.7 *** 27.26 ***

Final Oil Temp *** 207.3 *** 212.2 ***

Drive Time *** 30.7 *** 26 ***

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[ July 20, 2005, 12:08 PM: Message edited by: 59 Vetteman ]

 

[bulwnkl]

**POST DELETED** You changed your story as to what kind of oil cooler you have on the car.

[ July 20, 2005, 12:03 PM: Message edited by: bulwnkl ]

 

[Gary Allan]

That, in any definition of the term, is an oil cooler. It is more efficient than a air/oil radiator. The density of the coolant trumps the difference in differential. This is the preferred way to regulate your oil temp. They both are in spec at about the same temperature. They buffer each other and have one thermostatic control. You're reduced to assuring that the radiator is of high enough capacity.

I believe that I asked you about this a couple of times. I was really LOOKING for a reason that you achieved 200F oil temps so quickly.

quote:

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Originally posted by Gary Allan:
..do you have a coolant/oil heat exchanger?? This would explain your relatively short warm up period and your apparent tendancy for sticking around 212°F as the normal peak temp.

No this car does not have coolant/oil heat exchanger..it does have small oil cooler though..

oil will stay @ 212 or so if my speed stays below 75 or in city driving (closer to 205-210)..once you get over 80 it will near 225...once I get close to or over triple digit speeds it will be between 225-250.

all these temperature observations are with dino Delvac 15w40.

Soon we will see what happens when GC goes in!

---

But ...that doesn't necessarily invalidate the data ...we still have to question why the 15w40 showed higher temps. Was it due to higher fractioal hp required to pump it ..adding load that the cooling system had to endure ..hence the sharing more heat with the sump??

 

[bulwnkl]

quote:

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The car does not have oil cooler...but it does have a heat exchanger between coolant and oil

---

Right. That really makes it hard to tell much. Originally you had said (in the other thread) that there was NOT a coolant-to-oil heat exchanger. Since there is, it's very difficult to separate coolant-induced heating versus mechanical heating. I have not run any checks so I don't know, but it still may show that, as predicted, thick oil requires more work and therefore heats up more quickly, but like I said it's just really hard to tell with a coolant-oil exchanger in there.

 

[1sttruck]

One would assume that using AC would present a greater load than using a 40 vs 30 weight oil, but the data doesn't show that either, so I'll guess that 'more work to use a 40W vs 30W oil makes 40W heat up quicker' isn't what is going on.

If thinner oil has better heat transfer then an oil cooler will put it at a disadvantage for getting it up to temp, but so will a cold engine as it will serve as a heat soak.

 

[XS650]

quote:

---

Originally posted by Gary Allan:
But ...that doesn't necessarily invalidate the data ...we still have to question why the 15w40 showed higher temps. Was it due to higher fractioal hp required to pump it ..adding load that the cooling system had to endure ..hence the sharing more heat with the sump??

---

More likely because of the extra work done to shear it in the bearings and on the cylinder walls.

 

[Blue99]

The result, as indicated by the data, of Delvac 15w40 heating up faster, does not surprise me.

But notice the effect of the higher ambient temperature trips of 86, 88, & 89 degrees during the 15w40 runs. This generated the shortest warm-up times of 11, 11, and 9 minutes.

Obviously, as the engine coolant moves up to operating temperature more quickly during the higher temps, the oil cooler/heat exchanger is putting more heat into the oil.

So the oil cooler/exchanger is skewing the results somewhat.

 

[XS650]

Nice work, but it looks like all your data variation is in the noise level except for final oil temperature wich is fairly consistant.

An interesing thing about that data though is that if you plot final oil temp vs air temp, the hotter the outside air, the cooler the final air temp. Not by much though. I thinks it's more just noise level stuff.

 

[zoomzoom]

let me post the data again for easier reading:

Car is 2001 Audi S4 2.7L V6 BiTurbo

Oil is GC 0W-30

Outside Temp. *** 79 *** 83 *** 76 *** 83 *** 79 *** 81 ***
Time to 200F *** 14 *** 12 *** 13 *** 13 *** 15 *** 12 ***
Miles to 200F *** 5.2 *** 7.4 *** 7 *** 6.9 *** 7.5 *** 8 ***
Avg. Speed *** 34 *** 32 *** 40 *** 35 *** 38 *** 24 ***
Avg. MPG *** 27.8 *** 27.1 *** 27.5 *** 27.3 *** 27.8 *** 22.4 ***
Final Oil Temp *** 208 *** 206 *** 210 *** 205 *** 205 *** 210 ***
Total Drive Time *** 30 *** 32 *** 25 *** 28 *** 27 *** 42 ***
AC Used *** no *** no *** no *** no *** no *** no ***

Oil is Delvac 15w40

Outside Temp. *** 76 *** 86 *** 75 *** 88 *** 76 *** 89 ***
Time to 200F *** 12 *** 11 *** 14 *** 11 *** 12 *** 9 ***
Miles to 200F *** 8 *** 7.2 *** 8.5 *** 5.9 *** 6 *** 6.4 ***
Avg. Speed *** 40 *** 35 *** 40 *** 37 *** 42 *** 35 ***
Avg. MPG *** 28.4 *** 27.3 *** 27.8 *** 25.1 *** 27.7 *** 25.1 ***
Final Oil Temp *** 212 *** 210 *** 215 *** 212 *** 212 *** 212 ***
Total Drive Time *** 25 *** 28 *** 25 *** 28 *** 24 *** 30 ***
AC Used *** no *** no *** no *** yes *** no *** no ***

now the averages:

Oil Used *** 0w30 *** 15w40 ***
Outside Temp. *** 80.2 *** 80.2 ***
Time to 200F *** 13.2 *** 12 ***
Miles to 200F *** 7.0 *** 7.12 ***
Avg. Speed *** 33.8 *** 38.8 ***
Avg. MPG *** 26.7 *** 27.26 ***
Final Oil Temp *** 207.3 *** 212.2 ***
Drive Time *** 30.7 *** 26 ***

 

[zoomzoom]

quote:

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Originally posted by bulwnkl:
**POST DELETED** You changed your story as to what kind of oil cooler you have on the car.

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The car does not have oil cooler...but it does have a heat exchanger between coolant and oil...so when the car is cold coolant will help oil get to operating temp faster and when you drive it hard it will help bring down the oil temp since coolant stays around 90C.

 

[Steve S]

quote:

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Originally posted by XS650:

quote:

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Originally posted by Gary Allan:
But ...that doesn't necessarily invalidate the data ...we still have to question why the 15w40 showed higher temps. Was it due to higher fractioal hp required to pump it ..adding load that the cooling system had to endure ..hence the sharing more heat with the sump??

---

More likely because of the extra work done to shear it in the bearings and on the cylinder walls.

---

How about since the oil is thicker when cooler more oil is being bypassed back into the pan. I can't back it up though.

 

[Mitch Alsup]

quote:

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Originally posted by Blue99:
The result, as indicated by the data, of Delvac 15w40 heating up faster, does not surprise me.

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I think the difference is insignificant--e.g. so close it really doen't matter.

 

[williar]

It would be interesting to run the same test with a lighter oil, such as M1 0w30.

 

[darkdan]

So GC is 12.8 cSt when the temp levels out.

The delvac is 15.5 cSt.

So much for the "if you use thicker oil it heats up enough to thin out to a lower grade" argument.

 

[427Z06]

quote:

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Originally posted by darkdan:
So GC is 12.8 cSt when the temp levels out.

The delvac is 15.5 cSt.

So much for the "if you use thicker oil it heats up enough to thin out to a lower grade" argument.

---

I believe you would have to significantly increase the average power levels to see this effect, and here, the oil cooler tends to mitigate it.

 

[zoomzoom]

on my way home yesterday I was monitoring my coolant temp..this audi has a way of displaying coolant temp in C on my climate control display.

I takes really short time for coolant to get up to 90 C, mile or so...

Once on the highway it stays around 93 C at cruise speeds around 70mph.

once you get into city traffic it goes to 95 C and after a car is turned off it will climb to 104 C..

3 scenarios:

1. Cold engine
since the coolant gets to 90C(194F) fast it will warm the oil until temp equilibrium is reached.

2. City driving
coolant is at 95C(203F) so it will take away heat form oil and that explains why my oil temp is always less then 100C in city traffic.

3. Highway driving
collant is at 93(199.4F) so it will take a heat away from oil, but the oil temp will stay higher due to the higher termal input form the engine at highway speeds.

 

[jbas]

"So much for the "if you use thicker oil it heats up enough to thin out to a lower grade" argument."

And what about his MPG results? Thicker gained more MPG(?) Actually coincides with my recent experience of going from Amsoil 0w30 to Pennzoil 'base 10w30 in my Chrysler 2.4L, and the gas mileage - on paper anyway - increased!!!

 

[427Z06]

quote:

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Originally posted by jbas:
And what about his MPG results? Thicker gained more MPG(?)

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Ask anyone who does testing at one of the automakers the lengths they go through to be able to measure a 2% difference in fuel economy in a vehicle and have statistically significant results.

 

[XS650]

quote:

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Originally posted by 427Z06:

quote:

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Originally posted by jbas:
And what about his MPG results? Thicker gained more MPG(?)

---

Ask anyone who does testing at one of the automakers the lengths they go through to be able to measure a 2% difference in fuel economy in a vehicle and have statistically significant results.

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Real test engineers don't use faith based testing. If they did, they would be able to establish a trend from one tank of gas like a lot of non-test engineers do.