I understand the different cold temp grades and what factors they play during cold startup but what effect does operating temerature weight have on engines? Is it better to have thicker or thinner operating temperature weight in winter?
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Operating Temp Weight - #w20, #w30, #w40
- Thread starter byez
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"Is it better to have thicker or thinner operating temperature weight in winter?"
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Ideally the running viscosity would remain relatively unchanged no matter the ambient OR running temp. Realistically though, heat exchange rates through the oil pan and load rates will cause overall temperature fluctuations, and due to thermal behavior of the oil fluid and flow characteristics, there are temperature gradients within the flow regions that grow with increasing workload. An oil-coolant/air (with thermo) heat exchanger would help regulate oil temps better, but a gradient is inevitable (it exists with the engine coolant system as well, only water/antifreeze has a better thermal transfer and flow rate, so I figure.).
That said, one would IDEALLY not need to change oil weights no matter the swing in ambient temps, but one usually doesn't find such extreme measures of temperature management in the everyday consumer vehicle. One might otherwise chose a lower running weight (within OE recommendations...or not as some have experimented and continue to do so), in winter attributed to the greater heat transfer potential from colder air around oil pan if increasingly expecting to be at speed, as well as the general observation that lower running weights also have better cold flow characteristics at comparable temperatures, which aids starting and decreases a mpg penalty the more one finds themselves doing short trips (oil increasingly not being run-up to operating temps - increasing energy loss to pump oil).
Take care.
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"Is it better to have thicker or thinner operating temperature weight in winter?"
-----
Ideally the running viscosity would remain relatively unchanged no matter the ambient OR running temp. Realistically though, heat exchange rates through the oil pan and load rates will cause overall temperature fluctuations, and due to thermal behavior of the oil fluid and flow characteristics, there are temperature gradients within the flow regions that grow with increasing workload. An oil-coolant/air (with thermo) heat exchanger would help regulate oil temps better, but a gradient is inevitable (it exists with the engine coolant system as well, only water/antifreeze has a better thermal transfer and flow rate, so I figure.).
That said, one would IDEALLY not need to change oil weights no matter the swing in ambient temps, but one usually doesn't find such extreme measures of temperature management in the everyday consumer vehicle. One might otherwise chose a lower running weight (within OE recommendations...or not as some have experimented and continue to do so), in winter attributed to the greater heat transfer potential from colder air around oil pan if increasingly expecting to be at speed, as well as the general observation that lower running weights also have better cold flow characteristics at comparable temperatures, which aids starting and decreases a mpg penalty the more one finds themselves doing short trips (oil increasingly not being run-up to operating temps - increasing energy loss to pump oil).
Take care.
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byez,
Curious about said it all. The deal is that the difference in operating temp weight is hardly anything compared to cold temp weight. You want the thinnest oil possible during the warm up period while still maintaining the minimum acceptable operating temp weight that works with your engine. Most engines can work just fine with 20 weight oils. Some cannot. Synthetics are the best bet on having the least thickening when cold for a given hot temp spec.
Curious about said it all. The deal is that the difference in operating temp weight is hardly anything compared to cold temp weight. You want the thinnest oil possible during the warm up period while still maintaining the minimum acceptable operating temp weight that works with your engine. Most engines can work just fine with 20 weight oils. Some cannot. Synthetics are the best bet on having the least thickening when cold for a given hot temp spec.
FWIW: According to a NORIA publication, the following grades will have approximate equal viscosities when at the temperatures listed:
SAE 50 @ 260F
SAE 40 @ 240F
SAE 30 @ 220F
SAE 20 @ 190F
Also says multiviscosity and straight weight with the same back number (e.g., SAE 30 and 10w30) will be very similar.
SAE 50 @ 260F
SAE 40 @ 240F
SAE 30 @ 220F
SAE 20 @ 190F
Also says multiviscosity and straight weight with the same back number (e.g., SAE 30 and 10w30) will be very similar.
Originally Posted By: byez
Is it better to have thicker or thinner operating temperature weight in winter?
My theory is thicker helps offset fuel dilution thinning, and if that's backwards TELL ME. On a cool morning my old Nissan is still warming up even after my 25 minute highway drive to work. Running high mileage 10w30, 20w-50 mix.
Is it better to have thicker or thinner operating temperature weight in winter?
My theory is thicker helps offset fuel dilution thinning, and if that's backwards TELL ME. On a cool morning my old Nissan is still warming up even after my 25 minute highway drive to work. Running high mileage 10w30, 20w-50 mix.
Originally Posted By: jorton
Originally Posted By: byez
Is it better to have thicker or thinner operating temperature weight in winter?
On a cool morning my old Nissan is still warming up even after my 25 minute highway drive to work.
If you have not reached full operating temp after 5 mins let alone 25 mins of highway driving you need to replace your thermostat as it has failed open preventing your engine from properly heating up.
Originally Posted By: byez
Is it better to have thicker or thinner operating temperature weight in winter?
On a cool morning my old Nissan is still warming up even after my 25 minute highway drive to work.
If you have not reached full operating temp after 5 mins let alone 25 mins of highway driving you need to replace your thermostat as it has failed open preventing your engine from properly heating up.
Quote:
If you have not reached full operating temp after 5 mins let alone 25 mins of highway driving you need to replace your thermostat as it has failed open preventing your engine from properly heating up.
Are you talking water operating temp? Then yes...5 mins should be plenty.
If you are talking about oil operating temp which was what I believe the original question was about, I've never owned a car that got to oil operating temp within 5 mins.
In fact, my Charger takes about 20 mins to reach it's normal 220-222*F oil temp at highway speeds.
If you have not reached full operating temp after 5 mins let alone 25 mins of highway driving you need to replace your thermostat as it has failed open preventing your engine from properly heating up.
Are you talking water operating temp? Then yes...5 mins should be plenty.
If you are talking about oil operating temp which was what I believe the original question was about, I've never owned a car that got to oil operating temp within 5 mins.
In fact, my Charger takes about 20 mins to reach it's normal 220-222*F oil temp at highway speeds.
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It's something to see numbers like what NORIA gives as what I guess is a rough guideline. Clearances, surface area, surface finishes, load, operating rpm and oil supply rate(s) are other variables that are not taken into account, though perhaps averaged.
Still food for thought.
Take care.
Still food for thought.
Take care.
I've been wondering about this myself. It takes about a mile for my coolant temp to reach operating temperature(according to the stock gauge). The oil reaches 160 at the end of my 10 mile trip to or from work. Now with the colder temps (30s)the oil just hits 150 by the time I get home.
I have a 6 quart capacity running 0w20.
I have a 6 quart capacity running 0w20.
I was refering to the water temp as most cars today do not have an oil temp guage. And as to the water temp gauges in many cars today there is a resistor in the circuit that forces a normal reading to be displayed most of the time. This was done to reduce the number of people going to their dealers complaining about "overheating" when their gauge went just above the normal line during the summer months after spending all winter below that line.
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Oil does not get as hot in winter, for sure.
Therefore you can use a thinner oil.
Therefore you can use a thinner oil.
Originally Posted By: Robert1955
Originally Posted By: jorton
Originally Posted By: byez
Is it better to have thicker or thinner operating temperature weight in winter?
On a cool morning my old Nissan is still warming up even after my 25 minute highway drive to work.
If you have not reached full operating temp after 5 mins let alone 25 mins of highway driving you need to replace your thermostat as it has failed open preventing your engine from properly heating up.
After 5 minutes water temp is always normal. On cool mornings idle speed is still fast when I get to work. Must be too cool inside the engine compartment. Probably my fault for removing plastic close-outs from under the radiator. I see multiple rings(fuel)on blotter card, too.
If the thermostat failed to open, car would have boiled over last summer.
Originally Posted By: jorton
Originally Posted By: byez
Is it better to have thicker or thinner operating temperature weight in winter?
On a cool morning my old Nissan is still warming up even after my 25 minute highway drive to work.
If you have not reached full operating temp after 5 mins let alone 25 mins of highway driving you need to replace your thermostat as it has failed open preventing your engine from properly heating up.
After 5 minutes water temp is always normal. On cool mornings idle speed is still fast when I get to work. Must be too cool inside the engine compartment. Probably my fault for removing plastic close-outs from under the radiator. I see multiple rings(fuel)on blotter card, too.
If the thermostat failed to open, car would have boiled over last summer.
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Quote:
replace your thermostat as it has failed open
Quote:
If the thermostat failed to open
replace your thermostat as it has failed open
Quote:
If the thermostat failed to open
Like Gary has pointed out above I said that your thermostat was stuck open not that it is stuck closed. Most people do not realize that the thermostat (usually) has no control over the high temp your engine will get to, it just controls the minimum operating temp i.e a 192deg F will make your engine warm up to that point then it will open to allow coolant to flow thru the system and maintain that temp by closing and or opening to regulating total coolant(water)flow to maintain the temp it was built for.
Having said that I thought in the begining thats what you were talking about - water temps not oil temps.
Having said that I thought in the begining thats what you were talking about - water temps not oil temps.
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