Does thinner oil heat up more quickly on start up?

[BuickGN]

One thing I think we all agree on thick or thin is that getting the engine to operating temp as quickly as possible is a good thing.

I've realized how deep my oil obsession goes when I almost ordered a pan heater and block heater for the TL for my 32F to 110F climate. I guess admitting it is the first step to recovery.

 

[demarpaint]

Originally Posted By: mechtech2
Viscosity when cold is my only consideration, and that is important.
Thinner oils do run cooler, like when on a long run on the highway - maybe 10 deg. F or so.
But are thin oils warmer/cooler from start to mid temps.?
Not an issue, and has no practical value.


I'm with you, and prefer a 0W-xx oil if I'm using a synthetic oil, in an engine that is leak free. I've been told the 0W-xx oils can find their way out of an engine that has slight leaks, where as a 5W-xx is a little less likely to leak. I can only speak from what I've heard, I am fortunate the two vehicles I run synthetic oils in don't leak.

I think the faster an oil gets to operating temps no matter what ambient temperatures are is a plus. In lets say 70*F and hotter it won't matter much at all, but when temps get to say 50*F and below an oil that reaches operating temps, faster is best. Providing it is a viscosity spec'd for the engine.

 

[BuickGN]

Originally Posted By: demarpaint
Originally Posted By: mechtech2
Viscosity when cold is my only consideration, and that is important.
Thinner oils do run cooler, like when on a long run on the highway - maybe 10 deg. F or so.
But are thin oils warmer/cooler from start to mid temps.?
Not an issue, and has no practical value.


I'm with you, and prefer a 0W-xx oil if I'm using a synthetic oil, in an engine that is leak free. I've been told the 0W-xx oils can find their way out of an engine that has slight leaks, where as a 5W-xx is a little less likely to leak. I can only speak from what I've heard, I am fortunate the two vehicles I run synthetic oils in don't leak.

I think the faster an oil gets to operating temps no matter what ambient temperatures are is a plus. In lets say 70*F and hotter it won't matter much at all, but when temps get to say 50*F and below an oil that reaches operating temps, faster is best. Providing it is a viscosity spec'd for the engine.


I don't get why you would run a 0w in a fairly warm 50F... It's just not necessary. It won't get to internals any faster than a 10w. Now if you're a short tripper, by all means use it.

 

[SuperBusa]

"Does thinner oil heat up more quickly on start up?"

It all depends on the heat capacity of the oil. I doubt there is much of a difference in heat capacity to see, but technically if say 1 qt of 20w-50 weighs more than a qt of 0w-20 then the 0w-20 should gain temperature a little faster if the same amount of BTUs is absorbed by it.

The heating of the oil is mainly from heat generated due to combustion process, and the direct and indirect heat transfer to the oil. I doubt the actual shearing of the oil in the bearings, etc contributes much of the total heat input ... at least not enough to see any real difference on the road.

 

[SuperBusa]

Originally Posted By: BuickGN
Originally Posted By: oilyriser
Thin oil will flow through the bearings and heads sooner instead of getting bypassed back to the sump, so it should warm up faster.


No, as long as it's correct for the ambient temps thicker oil will flow through the bearings and heads just as quickly.


Yep ... pretty much, due to the fact that the oil pump is a positive displacement device. It tries to push the same volume through the system, and will up to the point of pressure relief.

If a super thick oil was used, the pump would go into pressure relief sooner, and then the amount of oil volume being pushed through the engine would show a decrease as compared to a thinner oil ... but only at pressure relief point and above.

 

[SuperBusa]

Originally Posted By: labman
I see little way for the average car owner to tell how much the oil pump is bypassing.


The only way you can get an idea if your oil pump is in pressure relief mode or not (you call it "bypassing"), is if you have a decent engine oil pressure gauge.

When the oil is cold, and you run the engine up in RPM you will see the oil pressure go up to a max value and hold there. Let's say the oil pressure reads 75 psi at 3000 RPM and above with cold oil. After warm up at 3000 RPM the gauge, the gauge might only read 45 psi. This would indicate that the 75 psi reading was with the pump in pressure relief.

 

[Gary Allan]

Originally Posted By: BuickGN

I've realized how deep my oil obsession goes when I almost ordered a pan heater and block heater for the TL for my 32F to 110F climate. I guess admitting it is the first step to recovery.



To recover ..first you have to have a problem. What's the problem?

 

[BuickGN]

Originally Posted By: Gary Allan
Originally Posted By: BuickGN

I've realized how deep my oil obsession goes when I almost ordered a pan heater and block heater for the TL for my 32F to 110F climate. I guess admitting it is the first step to recovery.



To recover ..first you have to have a problem. What's the problem?

I like your thinking...

 

[Gary Allan]

Originally Posted By: BuickGN
Originally Posted By: oilyriser
Thin oil will flow through the bearings and heads sooner instead of getting bypassed back to the sump, so it should warm up faster.


No, as long as it's correct for the ambient temps thicker oil will flow through the bearings and heads just as quickly.


Well, it's going to depend on the visc/temp. If your pump is spinning its tires, there's going to be less volume. Now depending on how your engine caches oil ..if your oil filter stays reasonably full ..then the "time to flow" will be the same. You may be pushing tooth paste, but flow will surely be there at whatever volume is available.

I can see that if that's where you're coming from.

 

[BuickGN]

Originally Posted By: Gary Allan
Originally Posted By: BuickGN
Originally Posted By: oilyriser
Thin oil will flow through the bearings and heads sooner instead of getting bypassed back to the sump, so it should warm up faster.


No, as long as it's correct for the ambient temps thicker oil will flow through the bearings and heads just as quickly.


Well, it's going to depend on the visc/temp. If your pump is spinning its tires, there's going to be less volume. Now depending on how your engine caches oil ..if your oil filter stays reasonably full ..then the "time to flow" will be the same. You may be pushing tooth paste, but flow will surely be there at whatever volume is available.

I can see that if that's where you're coming from.


Which brings up another point. I see many people that are obsessed with startup flow, the time it takes for oil to reach every part of the engine, but the same people don't go out and find which oil filter has the best ADBV. I would think this would contribute more to the time to pressure and flow and a 0w vs 5w oil.

 

[CATERHAM]

Originally Posted By: demarpaint
Originally Posted By: Steve S
I have to agree 100% on the oil pan heater there is always talk about cold start wear . The time it takes the oil to get to the oil pump from the pan is the most important item on the list of what causes cold start wear because it is probably the only thing that will make a difference in extreme cold.


That's how I feel. The only question I have is once the engine is fired up, does the oil cool off as it hits the colder upper regions of the engine? Or is enough heat generated to maintain the temps achieved by the pan warmer, and the temp slowly rises from there?

That's why I think a block heater/pan warmer is the best combo for Northern USA and Canada. But given a choice of only 1 I'd still go with the oil pan heater. JMO


The other thing that's important, particularily if you live in a northern climate, is a heat exchanger. In fact I wouldn't buy a new car that didn't have one, and if I knew how to practically install one I would in a couple of my cars.
If you're a true motorhead like I am, and really want to scare yourself, install an oil temperature gauge. In the winter the oil NEVER comes close to hitting proper operating temperature. I'd say cars without a heat exchanger typically run oil temps in the 125F to 140F range max'. At those temps even a light 0W-20 is more like a 60 wt oil in the sump.

 

[BuickGN]

Originally Posted By: CATERHAM
Originally Posted By: demarpaint
Originally Posted By: Steve S
I have to agree 100% on the oil pan heater there is always talk about cold start wear . The time it takes the oil to get to the oil pump from the pan is the most important item on the list of what causes cold start wear because it is probably the only thing that will make a difference in extreme cold.


That's how I feel. The only question I have is once the engine is fired up, does the oil cool off as it hits the colder upper regions of the engine? Or is enough heat generated to maintain the temps achieved by the pan warmer, and the temp slowly rises from there?

That's why I think a block heater/pan warmer is the best combo for Northern USA and Canada. But given a choice of only 1 I'd still go with the oil pan heater. JMO


The other thing that's important, particularily if you live in a northern climate, is a heat exchanger. In fact I wouldn't buy a new car that didn't have one, and if I knew how to practically install one I would in a couple of my cars.
If you're a true motorhead like I am, and really want to scare yourself, install an oil temperature gauge. In the winter the oil NEVER comes close to hitting proper operating temperature. I'd say cars without a heat exchanger typically run oil temps in the 125F to 140F range max'. At those temps even a light 0W-20 is more like a 60 wt oil in the sump.


Depends on the car and driving conditions.

Before the addition of the cooler, my GN would hit a good 160 in the winter with mild city driving and 180+ going down the freeway. Summer added 20 degrees to those figures and under boost the temps would rise very quickly.

I didn't want to deal with an oil thermostat so after seeing 120 degree temps in the winter with the cooler, I installed it out of the main airflow and added a fan with a thermostat that turned it on at 180 degrees. Even with the cooler, I can quickly overwhelm it with just a little aggressive driving.

 

[Gary Allan]

That's considered a non-issue from the OEM. In the case of (something like) Ford ..with their "S" suffix on the filters, it has to be for customer complaints. If it was some vital engine longevity issue, there would be some prohibition on nitrile ADBV and alternative aftermarket parts would not be able to state "meets or exceeds" if that was a mandated part of the spec. The ADBV spec's don't require 100% integrity as a spec. They merely have to slow/delay the back flow for xxx amount of time.

That's where you get into the potential effects of the time component due to viscosity. I personally don't latch on to this too much since the engine is under no load (bearings, anyway) and is stone cold (it's got a ways to sizzle what oil is there).

..but you can always stretch it to extremes ..and in this case, shorter/less is better.

 

[BuickGN]

Originally Posted By: Gary Allan
That's considered a non-issue from the OEM. In the case of (something like) Ford ..with their "S" suffix on the filters, it has to be for customer complaints. If it was some vital engine longevity issue, there would be some prohibition on nitrile ADBV and alternative aftermarket parts would not be able to state "meets or exceeds" if that was a mandated part of the spec. The ADBV spec's don't require 100% integrity as a spec. They merely have to slow/delay the back flow for xxx amount of time.

That's where you get into the potential effects of the time component due to viscosity. I personally don't latch on to this too much since the engine is under no load (bearings, anyway) and is stone cold (it's got a ways to sizzle what oil is there).

..but you can always stretch it to extremes ..and in this case, shorter/less is better.

But if they stop the backflow completely, it seems this would be more important than fighting over a very small difference in viscosity.

I've stated it before, there was no difference in the time it takes for the oil pressure light to go out from a 20wt to a straight 30wt yet changing brands of filters of the same size made a noticable difference.

 

[Gary Allan]

Quote:
But if they stop the backflow completely, it seems this would be more important than fighting over a very small difference in viscosity.


Apparently it's hard to achieve and not considered that important. Due to orientation, most GM's didn't have ADBV's at all. Once the center tube was breached, it stopps any back siphon. I have to assume that there was no substantial oil column above the filter.

But as far as a "very small" difference in viscosity ..that tends to broaden as one moves colder. Again, in your case, I wouldn't do anything other than what you're doing. Nor do I where the OEM spec'd 15w-40 for all climates. We don't have the ability yet to make an oil for all conditions. When electric oil pump systems become widely adopted (as Doug has told us are in use in some high end alloy) then many of these issues will evaporate.

Some will look at a pre-oiler as a waste of money, but I'll venture that when electric "volume/pressure on demand" systems trickle down to the commercial or mundane, you'll see them used to an advantage at the initial starting of the engine.

That is, until we have oils with a VI of 600+

 

[CATERHAM]

Originally Posted By: BuickGN
Originally Posted By: CATERHAM
Originally Posted By: demarpaint
Originally Posted By: Steve S
I have to agree 100% on the oil pan heater there is always talk about cold start wear . The time it takes the oil to get to the oil pump from the pan is the most important item on the list of what causes cold start wear because it is probably the only thing that will make a difference in extreme cold.


That's how I feel. The only question I have is once the engine is fired up, does the oil cool off as it hits the colder upper regions of the engine? Or is enough heat generated to maintain the temps achieved by the pan warmer, and the temp slowly rises from there?

That's why I think a block heater/pan warmer is the best combo for Northern USA and Canada. But given a choice of only 1 I'd still go with the oil pan heater. JMO


The other thing that's important, particularily if you live in a northern climate, is a heat exchanger. In fact I wouldn't buy a new car that didn't have one, and if I knew how to practically install one I would in a couple of my cars.
If you're a true motorhead like I am, and really want to scare yourself, install an oil temperature gauge. In the winter the oil NEVER comes close to hitting proper operating temperature. I'd say cars without a heat exchanger typically run oil temps in the 125F to 140F range max'. At those temps even a light 0W-20 is more like a 60 wt oil in the sump.


Depends on the car and driving conditions.

Before the addition of the cooler, my GN would hit a good 160 in the winter with mild city driving and 180+ going down the freeway. Summer added 20 degrees to those figures and under boost the temps would rise very quickly.

I didn't want to deal with an oil thermostat so after seeing 120 degree temps in the winter with the cooler, I installed it out of the main airflow and added a fan with a thermostat that turned it on at 180 degrees. Even with the cooler, I can quickly overwhelm it with just a little aggressive driving.


A hear exchanger where the coolant heats the oil, not an oil cooler.

 

[BuickGN]

Originally Posted By: Gary Allan
Quote:
But if they stop the backflow completely, it seems this would be more important than fighting over a very small difference in viscosity.


Apparently it's hard to achieve and not considered that important. Due to orientation, most GM's didn't have ADBV's at all. Once the center tube was breached, it stopps any back siphon. I have to assume that there was no substantial oil column above the filter.

But as far as a "very small" difference in viscosity ..that tends to broaden as one moves colder. Again, in your case, I wouldn't do anything other than what you're doing. Nor do I where the OEM spec'd 15w-40 for all climates. We don't have the ability yet to make an oil for all conditions. When electric oil pump systems become widely adopted (as Doug has told us are in use in some high end alloy) then many of these issues will evaporate.

Some will look at a pre-oiler as a waste of money, but I'll venture that when electric "volume/pressure on demand" systems trickle down to the commercial or mundane, you'll see them used to an advantage at the initial starting of the engine.

That is, until we have oils with a VI of 600+


That would be very neat, have the pump kick on a second before the engine fires. I do run a preluber on the GN. Originally for shutdown, not to prelube the engine but I'm sure it helps.

I'm not trying to argue, just to understand. You mention the column of oil. In my TL, there's a nearly foot column of oil above the filter and although the filter is oriented upright, the ADBV does make a difference on this car. It's maybe half a second difference in the amount of time it takes for the oil pressure light to go out if it sits overnight.

The GN is the same, but the filter is oriented nearly parallel with the ground. Of course, my results (pre-preluber) went against everything that is taught here and even my own common sense. It got pressure faster with a thicker oil. As it became worn, you could hear the rods rattle for the first second and literally as the guage moved it would disappear. I'm not sure if the thicker oil produced a better seal in the ADBV or if it helped the primative pump seal up and not bypass as much between the gears and end plate.

 

[BuickGN]

Originally Posted By: CATERHAM
Originally Posted By: BuickGN
Originally Posted By: CATERHAM
Originally Posted By: demarpaint
Originally Posted By: Steve S
I have to agree 100% on the oil pan heater there is always talk about cold start wear . The time it takes the oil to get to the oil pump from the pan is the most important item on the list of what causes cold start wear because it is probably the only thing that will make a difference in extreme cold.


That's how I feel. The only question I have is once the engine is fired up, does the oil cool off as it hits the colder upper regions of the engine? Or is enough heat generated to maintain the temps achieved by the pan warmer, and the temp slowly rises from there?

That's why I think a block heater/pan warmer is the best combo for Northern USA and Canada. But given a choice of only 1 I'd still go with the oil pan heater. JMO


The other thing that's important, particularily if you live in a northern climate, is a heat exchanger. In fact I wouldn't buy a new car that didn't have one, and if I knew how to practically install one I would in a couple of my cars.
If you're a true motorhead like I am, and really want to scare yourself, install an oil temperature gauge. In the winter the oil NEVER comes close to hitting proper operating temperature. I'd say cars without a heat exchanger typically run oil temps in the 125F to 140F range max'. At those temps even a light 0W-20 is more like a 60 wt oil in the sump.


Depends on the car and driving conditions.

Before the addition of the cooler, my GN would hit a good 160 in the winter with mild city driving and 180+ going down the freeway. Summer added 20 degrees to those figures and under boost the temps would rise very quickly.

I didn't want to deal with an oil thermostat so after seeing 120 degree temps in the winter with the cooler, I installed it out of the main airflow and added a fan with a thermostat that turned it on at 180 degrees. Even with the cooler, I can quickly overwhelm it with just a little aggressive driving.


A hear exchanger where the coolant heats the oil, not an oil cooler.


Ah, I should've specified an air to oil cooler. Looking back, a coolant to oil exchanger may have been better. I would run both but I want as little complexity in the oil system as I can get away with. Less stuff to fail.

As I get more wise, I'm starting to see the benefits of ultra fast warmup. I've changed my early morning startup routine to reflect this. In a car like my TL I would no doubt go with an oil to coolant exchanger. I just figured there would be a little extra cooling capacity with the oil to air unit and under boost it will surpass 280 quickly.

 

[SuperBusa]

Originally Posted By: BuickGN
Looking back, a coolant to oil exchanger may have been better.


Coolant to oil heat exchangers have two benefits ... it helps heat the oil quicker up to coolant temp, and also helps cool the oil to coolant temp. A lot of newer cars come standard with them. It also alleviates the need for a "cooler bypass" valve used in a standard air to oil cooler design to ensure the oil is not too cold.

Quote:
In a car like my TL


It might have one now ... depending on how new it is. My 04 Nissan V6 and also 05 Tacoma V6 both have a coolant-to-oil heat exchanger on the base of the oil filter mount - typically that's where they are located.

 

[demarpaint]

Originally Posted By: BuickGN
Originally Posted By: demarpaint
Originally Posted By: mechtech2
Viscosity when cold is my only consideration, and that is important.
Thinner oils do run cooler, like when on a long run on the highway - maybe 10 deg. F or so.
But are thin oils warmer/cooler from start to mid temps.?
Not an issue, and has no practical value.


I'm with you, and prefer a 0W-xx oil if I'm using a synthetic oil, in an engine that is leak free. I've been told the 0W-xx oils can find their way out of an engine that has slight leaks, where as a 5W-xx is a little less likely to leak. I can only speak from what I've heard, I am fortunate the two vehicles I run synthetic oils in don't leak.

I think the faster an oil gets to operating temps no matter what ambient temperatures are is a plus. In lets say 70*F and hotter it won't matter much at all, but when temps get to say 50*F and below an oil that reaches operating temps, faster is best. Providing it is a viscosity spec'd for the engine.


I don't get why you would run a 0w in a fairly warm 50F... It's just not necessary. It won't get to internals any faster than a 10w. Now if you're a short tripper, by all means use it.




Unfortunately because of the Incorporated Village, 3 cars and a one lane driveway, we have a forced short trip issue. We have to always move one vehicle to get the other two out. That and my wife caring for 2 sick parents locally makes for some short trip driving more often than not. We need all the help we can get from the oil.