WRX - Fear of Red Line 5W40 in Chicago Winter

a5m

Joined
Aug 9, 2021
Messages
36
Next OCI coming up. Been running Castrol Edge 0W40 but bit the bullet and decided to try Red Line 5W40. Mainly to change things up, but potentially improve wear and protection.

Less than 200 miles away. Figured 5W40 would be fine year-round, but with temps getting into the teens and single digits I'm having second thoughts now.

Castrol Edge 0W40 has a CCS of [email protected]°C and Viscosity at 40°C and 100°C of 74 and 13.2, while Red Line 5W40 CCS is [email protected]°C, Viscosity at 40°C and 100°C of 97 and 15.6. Plus Red Line is an ester based oil, so how does that factor in? Dave at Red Line said ester improves heat transfer but nothing to substantially alter warm up time. 5W40 would be fine but he recommended 5W30 for my application.

This is for a stock motor and tune 2010 WRX approaching 122K miles. Here is my last UOA on Castro Edge 0W40.

Given the butter-like toughness of these EJ engines, and the heavier than typical weight of Red Line oils, should I just stick to Castrol for another OCI and then RL once the weather warms up? Or am I overthinking this and should just send it?

In all honesty, I don't fully understand what the viscosity specs mean for the conditions I'm describing other than that the differences seem substantial. Haven't found anything specific to my application so posting this hoping someone can shed some light or point me in the right direction to understand all this better.

Thanks in advance.
 
Joined
Feb 6, 2021
Messages
874
Location
Massachusetts
Even a 10w would be fine above 0°F, 5w is good well into the negatives. Best thing to do in the cold is give your car 30-60 seconds idle time before driving off, then drive gently keeping RPM below 3k.

My personal choice for cold weather is M1 FS 0w40, it cranks very easily in very cold temperatures, better than Castrol 0w40 and RL 0w40.
 
Joined
Feb 27, 2009
Messages
7,117
Location
down in the park
Next OCI coming up. Been running Castrol Edge 0W40 but bit the bullet and decided to try Red Line 5W40. Mainly to change things up, but potentially improve wear and protection.

Less than 200 miles away. Figured 5W40 would be fine year-round, but with temps getting into the teens and single digits I'm having second thoughts now.

Castrol Edge 0W40 has a CCS of [email protected]°C and Viscosity at 40°C and 100°C of 74 and 13.2, while Red Line 5W40 CCS is [email protected]°C, Viscosity at 40°C and 100°C of 97 and 15.6. Plus Red Line is an ester based oil, so how does that factor in? Dave at Red Line said ester improves heat transfer but nothing to substantially alter warm up time. 5W40 would be fine but he recommended 5W30 for my application.

This is for a stock motor and tune 2010 WRX approaching 122K miles. Here is my last UOA on Castro Edge 0W40.

Given the butter-like toughness of these EJ engines, and the heavier than typical weight of Red Line oils, should I just stick to Castrol for another OCI and then RL once the weather warms up? Or am I overthinking this and should just send it?

In all honesty, I don't fully understand what the viscosity specs mean for the conditions I'm describing other than that the differences seem substantial. Haven't found anything specific to my application so posting this hoping someone can shed some light or point me in the right direction to understand all this better.

Thanks in advance.

The diiference only becomes substantial at -30C, which is -22F. Other than that viscosity is your friend if you want engine protection. It ensures metal part separation at low and mid temperatures where the anti-wear chemistry is not fully activated.
 
Joined
Dec 28, 2011
Messages
3,906
I believe you are a ok with what you are using. If that worried, move to Mobil 1 0-40. The Mobil 1 is a little more like a heavy 30wt or a light 40wt depending on your view.
 
  • Like
Reactions: a5m
Joined
Dec 26, 2005
Messages
21,542
Location
Upper Midwest
Less than 200 miles away. Figured 5W40 would be fine year-round, but with temps getting into the teens and single digits I'm having second thoughts now.

Castrol Edge 0W40 has a CCS of [email protected]°C and Viscosity at 40°C and 100°C of 74 and 13.2, while Red Line 5W40 CCS is [email protected]°C, Viscosity at 40°C and 100°C of 97 and 15.6. Plus Red Line is an ester based oil, so how does that factor in? Dave at Red Line said ester improves heat transfer but nothing to substantially alter warm up time. 5W40 would be fine but he recommended 5W30 for my application.

In all honesty, I don't fully understand what the viscosity specs mean for the conditions I'm describing other than that the differences seem substantial. Haven't found anything specific to my application so posting this hoping someone can shed some light or point me in the right direction to understand all this better.
If you don't understand them then why are you worried about them? Use the winter rating, that's what it's for. And in your case with the temperatures you are listing the differences between an oil with a 5W rating and one with a 0W rating are meaningless. And given that, what is most important here is the condition of your battery.
 
Last edited:

OVERKILL

$100 Site Donor 2021
Joined
Apr 28, 2008
Messages
50,693
Location
Ontario, Canada
You appear to be shaving two digits off the CCS figures for both lubes. Edge would be 5,600cP at -35C, whilst the Redline product 5,800cP at -30C. The reason they are at different temperatures is because they have different Winter ratings (0W vs 5W). Unless you are seeing below -30C, the Redline is fine.
 
Last edited:

FZ1

Joined
Feb 7, 2008
Messages
5,516
Location
Texas
Next OCI coming up. Been running Castrol Edge 0W40 but bit the bullet and decided to try Red Line 5W40. Mainly to change things up, but potentially improve wear and protection.

Less than 200 miles away. Figured 5W40 would be fine year-round, but with temps getting into the teens and single digits I'm having second thoughts now.

Castrol Edge 0W40 has a CCS of [email protected]°C and Viscosity at 40°C and 100°C of 74 and 13.2, while Red Line 5W40 CCS is [email protected]°C, Viscosity at 40°C and 100°C of 97 and 15.6. Plus Red Line is an ester based oil, so how does that factor in? Dave at Red Line said ester improves heat transfer but nothing to substantially alter warm up time. 5W40 would be fine but he recommended 5W30 for my application.

This is for a stock motor and tune 2010 WRX approaching 122K miles. Here is my last UOA on Castro Edge 0W40.

Given the butter-like toughness of these EJ engines, and the heavier than typical weight of Red Line oils, should I just stick to Castrol for another OCI and then RL once the weather warms up? Or am I overthinking this and should just send it?

In all honesty, I don't fully understand what the viscosity specs mean for the conditions I'm describing other than that the differences seem substantial. Haven't found anything specific to my application so posting this hoping someone can shed some light or point me in the right direction to understand all this better.

Thanks in advance.
Save the Redline for summer. Run the 0w for cold weather. Best starting place for vis increase is the oil spec in the manual and/or the oil cap. .02
 
  • Like
Reactions: a5m
Joined
Aug 4, 2003
Messages
2,562
Location
NJ
Agreed with the others. You should be fine with 5W-40. There is someone here that ran RT6 5W-40 in his WRX some years ago during winter in WI.

Having said that, there is also the point that @kschachn mentioned about the battery. I noticed more of a starting difference with a better battery in single digit temps than I ever did with a 5W or 0W oil. While the EJ turbos do love thicker oil, you do not need to go as thick with Red Line due to a higher HTHS than typical oils. That's presuming that you're referring to the High Performance line and not the Professional Series line.
 
Joined
Nov 29, 2021
Messages
3,450
Even a 10w would be fine above 0°F, 5w is good well into the negatives. Best thing to do in the cold is give your car 30-60 seconds idle time before driving off, then drive gently keeping RPM below 3k.

My personal choice for cold weather is M1 FS 0w40, it cranks very easily in very cold temperatures, better than Castrol 0w40 and RL 0w40.
I personally believe that is because it has a lower HTHS than those two oils.
 
  • Like
Reactions: a5m
Joined
Jun 8, 2016
Messages
2,540
Location
Texas, USA
I remember when 5W-30 was the winter oil and 10W-40 was the summer oil in Wyoming (1980s). VERY cold winters, Castrol GTX, no issues.
Batteries were much more a problem than the oil, although I had heaters on both after a few years of jump starting in the 0 degree or colder weather.
 
  • Like
Reactions: a5m

a5m

Thread starter
Joined
Aug 9, 2021
Messages
36
Thanks all for your replies and suggestions. This thread sort of sums up my confusion about this topic, as we seem to have a 50/50 split on what I should do.

Even a 10w would be fine above 0°F, 5w is good well into the negatives. Best thing to do in the cold is give your car 30-60 seconds idle time before driving off, then drive gently keeping RPM below 3k.

My personal choice for cold weather is M1 FS 0w40, it cranks very easily in very cold temperatures, better than Castrol 0w40 and RL 0w40.
Thanks, I already practice this with the current fill. As someone mentioned, that might be with M1 due to it being a bit on the thin side.

If you don't understand them then why are you worried about them? Use the winter rating, that's what it's for. And in your case with the temperatures you are listing the differences between an oil with a 5W rating and one with a 0W rating are meaningless. And given that, what is most important here is the condition of your battery.
I'm worried because I want to fully understand them. I've read up on what those values are measuring, so I understand the definition so to speak, but am a bit unsure in terms of real-world use, specifically for my application. The EJ isn't anything special but not all engines are created equal. Just trying to prolong its life the best I can. Good point about the battery, I should be replacing mine soon.

You appear to be shaving two digits off the CCS figures for both lubes. Edge would be 5,600cP at -35C, whilst the Redline product 5,800cP at -30C. The reason they are at different temperatures is because they have different Winter ratings (0W vs 5W). Unless you are seeing below -30C, the Redline is fine.
Red Line lists the CCS in poise instead of centipoise so I went with that. Thanks for explaining the testing temp difference, that makes a lot of sense.

That redline 5W40 is too robust for you stock engine even in the Summer.. You should spec the 30 grade.
Can you return it?
I'm not sure that's true for an EJ, especially in the summer. As in most cases with Red Line, I had to order it online. I may be able to return it, but I don't think it'll make economical sense.

Agreed with the others. You should be fine with 5W-40. There is someone here that ran RT6 5W-40 in his WRX some years ago during winter in WI.

Having said that, there is also the point that @kschachn mentioned about the battery. I noticed more of a starting difference with a better battery in single digit temps than I ever did with a 5W or 0W oil. While the EJ turbos do love thicker oil, you do not need to go as thick with Red Line due to a higher HTHS than typical oils. That's presuming that you're referring to the High Performance line and not the Professional Series line.
P.S. - BTW, for the 2010 Model Year, the manual states that 10W-40 and 10W-50 is allowed down to -4F.
Thanks Dennis. Firstly yes, I'm referring to the High Performance line. My factory battery is getting pretty tired, as I've noticed sluggish starts on a couple really cold mornings. I'm not worried about the car starting due to viscosity, but about the oil getting to where it needs to in time. As much as I want to just do it, I may hold off for the summer. I don't know.

I've taken the manual recommendations with a grain of salt but hadn't come across this. Do you remember what section it's in?
 
Joined
Jun 22, 2015
Messages
1,351
Location
montreal ,canada
Next OCI coming up. Been running Castrol Edge 0W40 but bit the bullet and decided to try Red Line 5W40. Mainly to change things up, but potentially improve wear and protection.

Less than 200 miles away. Figured 5W40 would be fine year-round, but with temps getting into the teens and single digits I'm having second thoughts now.

Castrol Edge 0W40 has a CCS of [email protected]°C and Viscosity at 40°C and 100°C of 74 and 13.2, while Red Line 5W40 CCS is [email protected]°C, Viscosity at 40°C and 100°C of 97 and 15.6. Plus Red Line is an ester based oil, so how does that factor in? Dave at Red Line said ester improves heat transfer but nothing to substantially alter warm up time. 5W40 would be fine but he recommended 5W30 for my application.

This is for a stock motor and tune 2010 WRX approaching 122K miles. Here is my last UOA on Castro Edge 0W40.

Given the butter-like toughness of these EJ engines, and the heavier than typical weight of Red Line oils, should I just stick to Castrol for another OCI and then RL once the weather warms up? Or am I overthinking this and should just send it?

In all honesty, I don't fully understand what the viscosity specs mean for the conditions I'm describing other than that the differences seem substantial. Haven't found anything specific to my application so posting this hoping someone can shed some light or point me in the right direction to understand all this better.

Thanks in advance.
Too much ado about nothing. Castrol 0w40 year round.
 
Joined
Apr 30, 2004
Messages
1,618
Location
Indiana
Back in the day I ran 20W50 Valvoline in my 302 Z28 Camaro in Flint Mich. There were a few times at -20F I needed a jump start, but the motor was fine.
 
Top