0W-20 or 5W-30 alternate per Manual

[Tokay444]

The logic of retaining the zero is sound.

[Clipdat]

Right. Viscosity difference of having 0w vs 5w only really comes into play well below freezing temps.

Originally Posted by Tokay444

Which is 2 degrees above freezing.

Keep telling yourself that over and over, and eventually in your head it might become true.

Originally Posted by Tokay444

The logic of retaining the zero is sound.

[Tokay444]

Originally Posted by Clipdat

Right. Viscosity difference of having 0w vs 5w only really comes into play well below freezing temps.



Keep telling yourself that over and over, and eventually in your head it might become true.

The operating range of 40 stops well above freezing. So what is it you're suggesting he change to? 5w40? 10w40? 20w?

[Clipdat]

I don't think you understand how motor oil works, so I'm done discussing this with you.

Originally Posted by Tokay444

The operating range of 40 stops well above freezing. So what is it you're suggesting he change to? 5w40? 10w40? 20w?

[Tokay444]

Originally Posted by Clipdat

I don't think you understand how motor oil works, so I'm done discussing this with you.

I'm quite versed in how motor oil works, though I'm starting question your knowledge base, so please, continue.

[DandoX]

I have had this same debate with friends on more than a few occasions. Yes the operating temp to necessitate the 0w is much cooler than zero, however the thought is the oil will still flow around the engine faster and more efficiently during a cold start around 0 c than a 5w-30 which would be slightly thicker thus reducing wear and tear. Now I probably could switch to 5w-30 but it isn't like 0w-30 is going to harm anything. Until I get a used oil analysis myself I will defer to what mobil 1 recommended for the engine which is 0w-20 and 0w-30 for daily driving. I'm more concerned with cold start up wear and tear than running out of viscosity at higher temps which is unlikely since I don't plan on running this oil on track. However I do leave the option that the 5w-30 may be better suited but from the research I have done the 0w-30 I've been running seems to be adequate protection, this will be confirmed after the oil analyses.
My thinking is now that my engine is above 70k I may run 0w-30 in winter and then switch to 5w-30 for summer. Depending on my used oil results.

[Zentec]

Originally Posted by Tokay444

For cold starts.

They say cold starts in the OM the real reason is for fuel economy ratings and brackets. Hence why almost every new Toyota has 0w20 oil Tuck Camery Prius ect dosent matter. All comes down to Fuel economy.

[Tokay444]

Originally Posted by Zentec

They say cold starts in the OM the real reason is for fuel economy ratings and brackets. Hence why almost every new Toyota has 0w20 oil Tuck Camery Prius ect dosent matter. All comes down to Fuel economy.

The oil isn’t cold long enough for the 0 to have any affect on fuel economy.
The 20 is for fuel economy.

[Zentec]

Originally Posted by Tokay444

The oil isn’t cold long enough for the 0 to have any affect on fuel economy.
The 20 is for fuel economy.

Yes this is true as the 0 represents the cold weather tempature heance why it says for cold start. 0 acts as that viscosity at that tempature range. The 20 represents the viscosity at normal engine operating temperatures. But the time is not relevant as un less your in artic temperatures you will never reach that range. They give everyone 0w20 so they can sell to all countries and be covered and get the kick backs for more models that fit the fuel economy bracket.

Subi designed the tolerances to reach that 40 weight. So if your climate dose not reach the temps in your OM for the 0 run the 5w30 and be better off as you will have better protection. If you really track your car and keep it high load or do some crazy thing like FI then you should be at the 40 weight and have at minimum an oil cooler and temp gauges for it. It reall comes down to your climate and driving style/ application if you need an the higher weight oils.

[Tokay444]

Originally Posted by Zentec

Yes this is true as the 0 represents the cold weather tempature heance why it says for cold start. 0 acts as that viscosity at that tempature range. The 20 represents the viscosity at normal engine operating temperatures. But the time is not relevant as un less your in artic temperatures you will never reach that range. They give everyone 0w20 so they can sell to all countries and be covered and get the kick backs for more models that fit the fuel economy bracket.

Subi designed the clearances to reach that 40 weight. So if your climate dose not reach the temps in your OM for the 0 run the 5w30 and be better off as you will have better protection. If you really track your car and keep it high load or do some crazy thing like FI then you should be at the 40 weight and have at minimum an oil cooler and temp gauges for it. It reall comes down to your climate and driving style/ application if you need an the higher weight oils.

And how long you'd really like the engine to last. The 20 isn't in there for it's protection benefits.

[Capt Spaulding]

Originally Posted by Zentec

Yes this is true as the 0 represents the cold weather tempature heance why it says for cold start. 0 acts as that viscosity at that tempature range. The 20 represents the viscosity at normal engine operating temperatures. But the time is not relevant as un less your in artic temperatures you will never reach that range. They give everyone 0w20 so they can sell to all countries and be covered and get the kick backs for more models that fit the fuel economy bracket.

Subi designed the clearances to reach that 40 weight. So if your climate dose not reach the temps in your OM for the 0 run the 5w30 and be better off as you will have better protection. If you really track your car and keep it high load or do some crazy thing like FI then you should be at the 40 weight and have at minimum an oil cooler and temp gauges for it. It reall comes down to your climate and driving style/ application if you need an the higher weight oils.

Out of curiosity. Are we sure about this? What is the information source? I'd really like to believe it since in my motorcycle daze I ran Shell RTS 5w-40 in just about all the bikes with good results. In my part of the world it seldom drops below 40F. It does, however, get over 100F every day for several weeks a year and the highs exceed 95 for 4 to 5 months. At some point, I may want to switch.

[Tokay444]

Originally Posted by Capt Spaulding

Out of curiosity. Are we sure about this? What is the information source? I'd really like to believe it since in my motorcycle daze I ran Shell RTS 5w-40 in just about all the bikes with good results. In my part of the world it seldom drops below 40F. It does, however, get over 100F every day for several weeks a year and the highs exceed 95 for 4 to 5 months. At some point, I may want to switch.

The fact the Japanese manual, referenced in this thread tells you you can use 5w40 would be a good indicator.

[Zentec]

Originally Posted by Tokay444

And how long you'd really like the engine to last. The 20 isn't in there for it's protection benefits.

Nope your right it’s not in there at for protection it’s in for eco.

Personally as long as it can it’s a Subaru and Toyota so baring anything major and regular mantaince is done it will last for well over 100k they make quality stuff.

I have a friend in japan that works for Subaru so he sent me the pic of the brz OM that’s how I got the info straight from the source.

[Zentec]

Originally Posted by Capt Spaulding

Out of curiosity. Are we sure about this? What is the information source? I'd really like to believe it since in my motorcycle daze I ran Shell RTS 5w-40 in just about all the bikes with good results. In my part of the world it seldom drops below 40F. It does, however, get over 100F every day for several weeks a year and the highs exceed 95 for 4 to 5 months. At some point, I may want to switch.

I live in the desert I see upwards of 110f after my oil change I will be running 5w30. Once I get some extra cash I will be running an oil cooler. So your part of Texas your fine with the 5w30. If you track/race it the they recommend the racing oil that’s why it’s there. But for protection wise you will be fine with 5w30.