Our Oil Temperatures in cold weather...maybe RL 5W-20 is not such a bad idea?
12-16-2005, 06:36 AM
#1
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Our Oil Temperatures in cold weather...maybe RL 5W-20 is not such a bad idea?
<center><img src="http://x11.putfile.com/12/34817182869.jpg"></center><p>
So I did some looging on what kind of oil temperatures I see in my car during my commute to and from work.
Looking at these numbers I think that if you dont track and abuse your car running RL 5W-20 in cold winter months might not be such a bad idea?<ul><li><a href="http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic&f=1&t=013319" >Take a look at my data and discussion on oil forum</a></li></ul>
So I did some looging on what kind of oil temperatures I see in my car during my commute to and from work.
Looking at these numbers I think that if you dont track and abuse your car running RL 5W-20 in cold winter months might not be such a bad idea?<ul><li><a href="http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic&f=1&t=013319" >Take a look at my data and discussion on oil forum</a></li></ul>
12-16-2005, 06:56 AM
#3
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we need a 0W .. thin oil @ low temps .. 20 is the viscosity @ high temps ..that will not help either
<ul><li><a href="http://b6s4.com/wuzup/audi/tsb/audi_oil.pdf">have to consider this:</a></li></ul>
12-16-2005, 07:26 AM
#4
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but, oil viscosity it is the function of temperature..so
These ratings are given @ 100C
So if I have 5W-40 in my engine now and my oil temp never gets over 90C as it doesn't in this cold weather and normal driving conditions (info in the link provided above) that means that I am actually running with 50-60wt oil, not 40...
Therefore 20wt oil (I am talking about hot viscosity here) @ 90C would behave as 30-40wt oil.
Manufacturers give out their oil specs in one size fits all fashion..
You think someone driving in alaska and someone driving in florida will need same oil viscosity?
So if I have 5W-40 in my engine now and my oil temp never gets over 90C as it doesn't in this cold weather and normal driving conditions (info in the link provided above) that means that I am actually running with 50-60wt oil, not 40...
Therefore 20wt oil (I am talking about hot viscosity here) @ 90C would behave as 30-40wt oil.
Manufacturers give out their oil specs in one size fits all fashion..
You think someone driving in alaska and someone driving in florida will need same oil viscosity?
12-16-2005, 12:38 PM
#5
AudiWorld Super User
This would be a good arguement for a straight weight oil.
But with multigrade oil it shouldn't be a problem.
A 5w-30 oil means it flows like a straight 5 weight oil at a given (low) temperature, but protects like a straight 30 weight oil at a given (high) temperature.
So by using 5w-20 you get the same low temperature flow rate as a 5w-30, but only have the high temperature protection of a 20 weight. The same holds true for 5w-40...flows like a 5, but protects like a 40. Now, does that mean you need 40 weight high temperature protection for 17 minutes of stop-and-go commuting in the winter...probably not. However the Audi Engineering (VW502.00 spec) recomendation comes from Autobahn style 100+MPH driving for extended periods of time. So that is likely why they make the higher weight recomendations. Since that driving style nearly never happens in the US a 30 weight would be fine, or if you are daring a 20 weight. However I personally wouldn't sacrifice my high temperature protection by using a 20 weight oil.
A 5w-30 oil means it flows like a straight 5 weight oil at a given (low) temperature, but protects like a straight 30 weight oil at a given (high) temperature.
So by using 5w-20 you get the same low temperature flow rate as a 5w-30, but only have the high temperature protection of a 20 weight. The same holds true for 5w-40...flows like a 5, but protects like a 40. Now, does that mean you need 40 weight high temperature protection for 17 minutes of stop-and-go commuting in the winter...probably not. However the Audi Engineering (VW502.00 spec) recomendation comes from Autobahn style 100+MPH driving for extended periods of time. So that is likely why they make the higher weight recomendations. Since that driving style nearly never happens in the US a 30 weight would be fine, or if you are daring a 20 weight. However I personally wouldn't sacrifice my high temperature protection by using a 20 weight oil.
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