I was wondering about how long I should let my vehicles warm up with a 0w-xx before I actually take off and drive. I ask this because if the 0w is supposed to flow a little better in the cold temps compared to a 5w it's obviously thinner at startup. So the oil gets around inside the motor quicker but because it's thinner isn't it providing less protection? Seems like you'd want the oil temp to increase some to get the viscosity up before hit the gas and get the rpm's up. Even in the summer time (with 5w-xx) I usually let my vehicle run about a minute and a half to two minutes before driving (if it's been sitting). In winter I wait about 3-4 minutes on average. My wife on the other hand likes to turn the key and put her car in reverse all in one motion. I think I've finally got her broken of that bad habit though. Anyhow, just wondering about this.
Warm up time for 0w vs 5w or 10w
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So the oil gets around inside the motor quicker but because it's thinner isn't it providing less protection?
It is thinner than a comparable 5w or 10w oil, but it is still much thicker than your engine is designed for.
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Seems like you'd want the oil temp to increase some to get the viscosity up
The "viscosity" of the oil decreases as the temperature increases, not the other way around.
Do not think of the first number and the second number as the same unit of measure. The first number gives you an idea of the relative ease of pumping at extremely cold temperatures. The second number gives you an idea of the viscosity of the oil at "normal" oil temperatures in an at temperature engine of 100C.
I'd suggest reading this to get started:
http://www.bobistheoilguy.com/motor-oil-101/
So the oil gets around inside the motor quicker but because it's thinner isn't it providing less protection?
It is thinner than a comparable 5w or 10w oil, but it is still much thicker than your engine is designed for.
Quote:
Seems like you'd want the oil temp to increase some to get the viscosity up
The "viscosity" of the oil decreases as the temperature increases, not the other way around.
Do not think of the first number and the second number as the same unit of measure. The first number gives you an idea of the relative ease of pumping at extremely cold temperatures. The second number gives you an idea of the viscosity of the oil at "normal" oil temperatures in an at temperature engine of 100C.
I'd suggest reading this to get started:
http://www.bobistheoilguy.com/motor-oil-101/
Viscosity DECREASES as temperature increases. Conversely it increases as temperature decreases. It's best to pull away after the idle has settled down (a minute or less, typically) and drive gently. Idling takes too long to warm up the oil. Oil temperature typically takes around 15 minutes of driving to reach full operating temperature. The closer I get to that the more comfortable I am applying more load to the engine.
The temp coming up brings the viscosity down. The quicker you can get it to operating viscosity, which for an Xw30 is around 10, the better. Even if a 0w30 is thinner at 0C it is still much thicker than operating viscosity so no it isn't providing less protection.
As far as warm up, I don't warm my cars up very much just drive easy until they are up to temperature. I like the idea of the engine and transmission warming up together.
As far as warm up, I don't warm my cars up very much just drive easy until they are up to temperature. I like the idea of the engine and transmission warming up together.
also, idle warm ups are not the best way to warm up a car.
http://www.consumerenergycenter.org/myths/idling.html
once the engine has oil pressure and oil is circulating its best to drive rather then let it idle.
drive slowly and Conservatively.
Idling is such a inefficient way to warm up because it take FOREVER. This just means more time the engine is running cold, more time the oil is too thick, more time fuel can be contaminating the oil all while wasting gas because nothing is being accomplished while idling passed 30 seconds.
then once you idle your car for a very long time, you probably take off thinking everything is hot and ready to go, well what about the trans fluid? gear fluid?
its best to drive so that everything can be warmed up together and quickly.
On really cold days go out early and leave for your morning commute early, then drive the first few miles extra slowly. or take the long way out of your neighborhood before hitting major roads with faster speed limits.
Thats what i have been told
http://www.consumerenergycenter.org/myths/idling.html
once the engine has oil pressure and oil is circulating its best to drive rather then let it idle.
drive slowly and Conservatively.
Idling is such a inefficient way to warm up because it take FOREVER. This just means more time the engine is running cold, more time the oil is too thick, more time fuel can be contaminating the oil all while wasting gas because nothing is being accomplished while idling passed 30 seconds.
then once you idle your car for a very long time, you probably take off thinking everything is hot and ready to go, well what about the trans fluid? gear fluid?
its best to drive so that everything can be warmed up together and quickly.
On really cold days go out early and leave for your morning commute early, then drive the first few miles extra slowly. or take the long way out of your neighborhood before hitting major roads with faster speed limits.
Thats what i have been told
A couple of minutes is enough time. A 0w-oil is thinner than a 5w at startup, but it is not thin compared the viscosity either would have at 100C. Say you are comparing M1 0w30 to M1 5w30:
The 0w30 has a viscosity of 10.6 centistokes @ 100C.
The 5w30 has a viscosity of 11.3 centistokes @ 100C.
Minimum allowable viscosity of a 30-weight according to SAE specs is 9.3 cSt.
But on a start at 0C, the oil viscosities would be (according to the Widman calculator):
420 cSt for 0w30.
521 cSt for 5w30.
So the viscosity of the 0w30 is 20% lower than the 5w30 at the low startup temperature, but it is 45 times the minimum allowable viscosity for a 30-weight oil when at high temperature. The very high viscosity present on a cold start will give very high oil film thickness, but will cause a lot of viscous drag in the engine, leading to higher fuel consumption until the oil warms up and thins out.
The 0w30 has a viscosity of 10.6 centistokes @ 100C.
The 5w30 has a viscosity of 11.3 centistokes @ 100C.
Minimum allowable viscosity of a 30-weight according to SAE specs is 9.3 cSt.
But on a start at 0C, the oil viscosities would be (according to the Widman calculator):
420 cSt for 0w30.
521 cSt for 5w30.
So the viscosity of the 0w30 is 20% lower than the 5w30 at the low startup temperature, but it is 45 times the minimum allowable viscosity for a 30-weight oil when at high temperature. The very high viscosity present on a cold start will give very high oil film thickness, but will cause a lot of viscous drag in the engine, leading to higher fuel consumption until the oil warms up and thins out.
Start car. Put on seat belt, check mirror settings, seat settings, radio, HVAC, etc. Glance at oil pressure gauge to be sure its up to normal. Drive away and keep it gentle until the coolant temp gauge starts to climb.
Same procedure applies regardless of oil grade or engine, except in special cases like older diesels, some air-cooleds, some older carbureted cars that might be prone to stalling until the intake manifold hot-spot gets warm enough to fully vaporize fuel via exhaust gas heat, etc. Those might require a whole 90 seconds to two minutes.
As others have pointed out, the visc. difference between a 0wXX and a 5wXX at cold temps is certainly measurable, but compared to the HOT visc. that the engine really is designed for, its like the difference in height between a 6'6 guy and a 5'8 guy compared to the height of the Chrysler building.
Same procedure applies regardless of oil grade or engine, except in special cases like older diesels, some air-cooleds, some older carbureted cars that might be prone to stalling until the intake manifold hot-spot gets warm enough to fully vaporize fuel via exhaust gas heat, etc. Those might require a whole 90 seconds to two minutes.
As others have pointed out, the visc. difference between a 0wXX and a 5wXX at cold temps is certainly measurable, but compared to the HOT visc. that the engine really is designed for, its like the difference in height between a 6'6 guy and a 5'8 guy compared to the height of the Chrysler building.
Originally Posted By: Sonic
I ask this because if the 0w is supposed to flow a little better in the cold temps compared to a 5w it's obviously thinner at startup.
0w may be thinner than 5w but only once you get to really extreme arctic type ambient temps like below 0F. There isn't much difference between them otherwise.
Also, I'd say your idle times are excessive.
I ask this because if the 0w is supposed to flow a little better in the cold temps compared to a 5w it's obviously thinner at startup.
0w may be thinner than 5w but only once you get to really extreme arctic type ambient temps like below 0F. There isn't much difference between them otherwise.
Also, I'd say your idle times are excessive.
Thanks for the replies guys. I see I screwed up and use the term viscosity when what I should have wrote was weight. Yes, I do know that cold oil is thicker than warm oil, my bad. I just kept thinking that an oil that starts at 0w would take longer to get up to a 30w as compared to a 5w30 or 10w30. It seems everyone agrees to take it easy on the gas pedal when you first take off in cold weather and that was actually what got me asking about this in the first place. After I leave the house in the morning the oil is nowhere near a 30 weight, it started at 0. As the oil temp increases so does the weight and level of protection right? I'm probably overthinking this.
Originally Posted By: 440Magnum
Start car. Put on seat belt, check mirror settings, seat settings, radio, HVAC, etc. Glance at oil pressure gauge to be sure its up to normal. Drive away and keep it gentle until the coolant temp gauge starts to climb.
^^^ same here, turn key, wait for glow plugs, fire it up, make sure it has oil pressure and off I go.
Start car. Put on seat belt, check mirror settings, seat settings, radio, HVAC, etc. Glance at oil pressure gauge to be sure its up to normal. Drive away and keep it gentle until the coolant temp gauge starts to climb.
^^^ same here, turn key, wait for glow plugs, fire it up, make sure it has oil pressure and off I go.
Originally Posted By: Sonic
I just kept thinking that an oil that starts at 0w would take longer to get up to a 30w as compared to a 5w30 or 10w30.
Actually, it's just the opposite. Since a 0w-XX oil doesn't thicken up as much in cold weather, it should reach it's operating viscosity faster as the engine warms up.
I just kept thinking that an oil that starts at 0w would take longer to get up to a 30w as compared to a 5w30 or 10w30.
Actually, it's just the opposite. Since a 0w-XX oil doesn't thicken up as much in cold weather, it should reach it's operating viscosity faster as the engine warms up.
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Originally Posted By: Sonic
Thanks for the replies guys. I see I screwed up and use the term viscosity when what I should have wrote was weight. Yes, I do know that cold oil is thicker than warm oil, my bad. I just kept thinking that an oil that starts at 0w would take longer to get up to a 30w as compared to a 5w30 or 10w30. It seems everyone agrees to take it easy on the gas pedal when you first take off in cold weather and that was actually what got me asking about this in the first place. After I leave the house in the morning the oil is nowhere near a 30 weight, it started at 0. As the oil temp increases so does the weight and level of protection right? I'm probably overthinking this.
It sounds like you still don't quite grasp the concept.
The numbers before and after the "w" simply represent viscosity ranges at temp.
A straight 30 has to be between 9.30 and 12.49 cST @ 100C to be classified as a 30 weight oil.
The same goes for a multigrade with 30 after the "W". So 0w30, 5w30, 10w30, 15w30, 20w30, 25w30 and 30w30 would all fall inside this.
However, the number in front of the W, IE, the 0 in 0w30, the 5 in 5w30, the 10 in 10w30....etc corresponds with ANOTHER range of viscosities that are measured at a low-temp point that corresponds to that rating.
0w30 has to fall within this range at -40C
5w30 has to fall within this range at -35C
10w30 has to fall within this range at -30C
This is measured through MRV
So:
Mobil 1 0w30: 13,250cST @ -40C
P Ultra 5w30: 13,000cST @ -35C
PUltra 10w30: 10,300cST @ -30C
Thanks for the replies guys. I see I screwed up and use the term viscosity when what I should have wrote was weight. Yes, I do know that cold oil is thicker than warm oil, my bad. I just kept thinking that an oil that starts at 0w would take longer to get up to a 30w as compared to a 5w30 or 10w30. It seems everyone agrees to take it easy on the gas pedal when you first take off in cold weather and that was actually what got me asking about this in the first place. After I leave the house in the morning the oil is nowhere near a 30 weight, it started at 0. As the oil temp increases so does the weight and level of protection right? I'm probably overthinking this.
It sounds like you still don't quite grasp the concept.
The numbers before and after the "w" simply represent viscosity ranges at temp.
A straight 30 has to be between 9.30 and 12.49 cST @ 100C to be classified as a 30 weight oil.
The same goes for a multigrade with 30 after the "W". So 0w30, 5w30, 10w30, 15w30, 20w30, 25w30 and 30w30 would all fall inside this.
However, the number in front of the W, IE, the 0 in 0w30, the 5 in 5w30, the 10 in 10w30....etc corresponds with ANOTHER range of viscosities that are measured at a low-temp point that corresponds to that rating.
0w30 has to fall within this range at -40C
5w30 has to fall within this range at -35C
10w30 has to fall within this range at -30C
This is measured through MRV
So:
Mobil 1 0w30: 13,250cST @ -40C
P Ultra 5w30: 13,000cST @ -35C
PUltra 10w30: 10,300cST @ -30C
Good to know, that's why I'm here, to ask questions.
I had a guy in a motorcycle forum tell me the exact opposite a while back. We were discussing using oil such as T6 5w40 in colder weather as compared to a 20w50. He told me to let the bike warm up longer before taking off since it starts at such a low weight. Most bikes are spec'd for a 10wxx or 20wxx. But what you're saying makes sense though. Do you know if it is actually a fact or not? Thanks.
I had a guy in a motorcycle forum tell me the exact opposite a while back. We were discussing using oil such as T6 5w40 in colder weather as compared to a 20w50. He told me to let the bike warm up longer before taking off since it starts at such a low weight. Most bikes are spec'd for a 10wxx or 20wxx. But what you're saying makes sense though. Do you know if it is actually a fact or not? Thanks.
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Originally Posted By: Sonic
Good to know, that's why I'm here, to ask questions.
I had a guy in a motorcycle forum tell me the exact opposite a while back. We were discussing using oil such as T6 5w40 in colder weather as compared to a 20w50. He told me to let the bike warm up longer before taking off since it starts at such a low weight. Most bikes are spec'd for a 10wxx or 20wxx. But what you're saying makes sense though. Do you know if it is actually a fact or not? Thanks.
What I've posted above are how it is defined by the SAE (Society of Automotive Engineers).
The MRV values I posted are pulled directly from the product data sheets for those oils provided by their manufacturers.
It is accurate data.
All multi-grade oils start off heavier than their hot temperature by quite a wide margin. How wide this margin is can be easily witnessed by looking at an oil's PDS, which will often (but not always) show its low temp MRV value in cST (as I posted above). Another important factor is the oil's VI (Viscosity Index). The higher this number is, the less the oil thickens as it cools. This is how an oil like M1 0w40 can be thinner at all temps below 0 than Castrol "GC" 0w30, despite being heavier when hot.
Good to know, that's why I'm here, to ask questions.
I had a guy in a motorcycle forum tell me the exact opposite a while back. We were discussing using oil such as T6 5w40 in colder weather as compared to a 20w50. He told me to let the bike warm up longer before taking off since it starts at such a low weight. Most bikes are spec'd for a 10wxx or 20wxx. But what you're saying makes sense though. Do you know if it is actually a fact or not? Thanks.
What I've posted above are how it is defined by the SAE (Society of Automotive Engineers).
The MRV values I posted are pulled directly from the product data sheets for those oils provided by their manufacturers.
It is accurate data.
All multi-grade oils start off heavier than their hot temperature by quite a wide margin. How wide this margin is can be easily witnessed by looking at an oil's PDS, which will often (but not always) show its low temp MRV value in cST (as I posted above). Another important factor is the oil's VI (Viscosity Index). The higher this number is, the less the oil thickens as it cools. This is how an oil like M1 0w40 can be thinner at all temps below 0 than Castrol "GC" 0w30, despite being heavier when hot.
Originally Posted By: Sonic
I had a guy in a motorcycle forum tell me the exact opposite a while back. We were discussing using oil such as T6 5w40 in colder weather as compared to a 20w50. He told me to let the bike warm up longer before taking off since it starts at such a low weight.
LOL! This is tragic.
Let's illustrate. It'll be an exaggeration, but I'm just trying to help you understand it better:
- When 5w-40 is first started at say 32F, it has consistency/thickness of light honey.
- When 20w-50 is first started at 32F, it has consistency/thickness of grease.
- When both 5w-40 and 20w-50 are at operating temp, they are similar in consistency/thickness to juice (the Xw-50 being just a slightly thicker juice, but both very fluid).
The object is to reach the juice consistency as quickly as possible. So, which of the two would you expect to get there faster? Answer: the one that's somewhat thinner to begin with (5w-40). So it is actually the 20w-50 that would need a longer warmup time in very cold weather. That is why most engine mfgs even don't suggest using a 20w-XX oil in very cold weather to begin with.
I had a guy in a motorcycle forum tell me the exact opposite a while back. We were discussing using oil such as T6 5w40 in colder weather as compared to a 20w50. He told me to let the bike warm up longer before taking off since it starts at such a low weight.
LOL! This is tragic.
Let's illustrate. It'll be an exaggeration, but I'm just trying to help you understand it better:
- When 5w-40 is first started at say 32F, it has consistency/thickness of light honey.
- When 20w-50 is first started at 32F, it has consistency/thickness of grease.
- When both 5w-40 and 20w-50 are at operating temp, they are similar in consistency/thickness to juice (the Xw-50 being just a slightly thicker juice, but both very fluid).
The object is to reach the juice consistency as quickly as possible. So, which of the two would you expect to get there faster? Answer: the one that's somewhat thinner to begin with (5w-40). So it is actually the 20w-50 that would need a longer warmup time in very cold weather. That is why most engine mfgs even don't suggest using a 20w-XX oil in very cold weather to begin with.
Originally Posted By: Quattro Pete
Originally Posted By: Sonic
I had a guy in a motorcycle forum tell me the exact opposite a while back. We were discussing using oil such as T6 5w40 in colder weather as compared to a 20w50. He told me to let the bike warm up longer before taking off since it starts at such a low weight.
LOL! This is tragic.
It is, very. But don't worry Sonic, you've come to the right place!
Originally Posted By: Sonic
I had a guy in a motorcycle forum tell me the exact opposite a while back. We were discussing using oil such as T6 5w40 in colder weather as compared to a 20w50. He told me to let the bike warm up longer before taking off since it starts at such a low weight.
LOL! This is tragic.
It is, very. But don't worry Sonic, you've come to the right place!
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I used to warm my car till the temp guage began to move before I`d drive away,but now I just let it idle for maybe a minute to make sure it`s good and lubed,then drive easy till the needle begins to move.
I let mine run about 5 minutes in winter: 6 pumps of pedal to the floor, turn key and engine starts. Give one quick shot after about 15 seconds to kick idle down one step, then wait for choke to open enough to drive.
In summer this takes only about 30 seconds to a minute.
In summer this takes only about 30 seconds to a minute.
Originally Posted By: Sonic
I was wondering about how long I should let my vehicles warm up with a 0w-xx before I actually take off and drive. I ask this because if the 0w is supposed to flow a little better in the cold temps compared to a 5w it's obviously thinner at startup. So the oil gets around inside the motor quicker but because it's thinner isn't it providing less protection? Seems like you'd want the oil temp to increase some to get the viscosity up before hit the gas and get the rpm's up. Even in the summer time (with 5w-xx) I usually let my vehicle run about a minute and a half to two minutes before driving (if it's been sitting). In winter I wait about 3-4 minutes on average. My wife on the other hand likes to turn the key and put her car in reverse all in one motion. I think I've finally got her broken of that bad habit though. Anyhow, just wondering about this.
There is no need to warm up an engine for more than 10 seconds. Thicker oil works better in the boundary-lubrication regime (such as in the valvetrain) anyway. But don't go over 4000 RPM before you reach the normal operating temperature and drive gently until then.
If the weather is extremely cold or the vehicle hasn't been driven for several days, it may be wise to warm up the engine for a minute or two. But, otherwise, ten seconds is sufficient to ensure oil flow.
Also note that ZDDP, moly, and most other antiwear additives in the oil don't get activated until you reach the normal operating temperature. Therefore, until you reach the normal operating temperature, your antiwear film on the metal parts will be wearing away and you should drive gently until the film starts forming again when the normal operating temperature is reached.
Once again, ten-second warm-up and gentle driving until normal operating temperature is best way to extend engine life. Lengthy warm-ups probably decrease the engine life and also waste fuel.
I was wondering about how long I should let my vehicles warm up with a 0w-xx before I actually take off and drive. I ask this because if the 0w is supposed to flow a little better in the cold temps compared to a 5w it's obviously thinner at startup. So the oil gets around inside the motor quicker but because it's thinner isn't it providing less protection? Seems like you'd want the oil temp to increase some to get the viscosity up before hit the gas and get the rpm's up. Even in the summer time (with 5w-xx) I usually let my vehicle run about a minute and a half to two minutes before driving (if it's been sitting). In winter I wait about 3-4 minutes on average. My wife on the other hand likes to turn the key and put her car in reverse all in one motion. I think I've finally got her broken of that bad habit though. Anyhow, just wondering about this.
There is no need to warm up an engine for more than 10 seconds. Thicker oil works better in the boundary-lubrication regime (such as in the valvetrain) anyway. But don't go over 4000 RPM before you reach the normal operating temperature and drive gently until then.
If the weather is extremely cold or the vehicle hasn't been driven for several days, it may be wise to warm up the engine for a minute or two. But, otherwise, ten seconds is sufficient to ensure oil flow.
Also note that ZDDP, moly, and most other antiwear additives in the oil don't get activated until you reach the normal operating temperature. Therefore, until you reach the normal operating temperature, your antiwear film on the metal parts will be wearing away and you should drive gently until the film starts forming again when the normal operating temperature is reached.
Once again, ten-second warm-up and gentle driving until normal operating temperature is best way to extend engine life. Lengthy warm-ups probably decrease the engine life and also waste fuel.
As well, lengthy warm-ups generate more polution as the catalytic convertor isn't as effective until it is warmed up.
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