Changing Oil Brands and Winter

[Fastbrz]

Originally Posted by jvincent

We're going to have to agree to disagree.

Agreed.

[bluesubie]

Originally Posted by sixthree

Hello,



Car noob here. I've been running Motul oil for the last 3 changes but plan on going to a subaru dealer to change it back to just the subaru provided oil. My original garage is too far away now and theres no one around my area that provides motul.



Is it okay to mix oil brands and is there such a thing as winter/cold weather ready oil??



Thanks

Motul 300V or Motul 8100?
It's ok to mix API certified oil, or oils made to API specs (Motul 8100), as they must pass ASTM D6922.

5.1 It is important that engine oils from different manufacturers be homogeneous and miscible with each other, because operators of automotive engines often do not have prior knowledge of the manufacturer of the oil that is currently used in their application, and engine failure can occur if oils are combined that do not stay homogeneous and function properly.

http://www.astm.org/Standards/D6922.htm

The cold cranking viscosity of 0W is measured at -35C and the cold cranking viscosity of 5W is measured at -30C. In both cases, this is regardless of what the second number is.

http://www.pqiamerica.com/coldcrank.htm

I guess you could say that 0W is more of the winter grade, but 5W will cover some very cold temps as well.

-Dennis

[OkieSnuffBox]

Originally Posted by Fastbrz

I do agree that it may be more track oriented but I think 10w30 offers way better protection. 0w-20 was picked for emissions.

What empirical evidence are you basing this on?


The trend toward lighter oils is because of better machining tolerances and the need for better fuel mileage (lighter oil = less drag on internal components = less lost HP).

[bluesubie]

Originally Posted by OkieSnuffBox

What empirical evidence are you basing this on?

The owner's manual? We're definitely and but in certain driving conditions (like the track as mentioned) the owner's manual absolutely allows it.

SAE 0W-20 is the best choice for good fuel economy and good starting in cold weather.

The 20 in 0W-20 indicates the viscosity characteristic of the oil when
the oil is at high temperature. An oil with a higher viscosity (one with a
higher value) may be better suited if the vehicle is operated at high

speeds, or under extreme load conditions.

A 10W-30 may not be needed, but it's certainly allowed and 0W-20 is recommended for fuel economy.

-Dennis

[jvincent]

I ran 0w20 on the track this year with no issues, other than some relatively high oil temps.

I am definitely getting an oil cooler and may consider 5w30 for track season.

IIRC, the heavier oil will result in more wear until it comes up to temperature, which will take longer. So there's a tradeoff. More wear vs high temp performance.

[bluesubie]

Originally Posted by jvincent

IIRC, the heavier oil will result in more wear until it comes up to temperature, which will take longer. So there's a tradeoff. More wear vs high temp performance.

Actually, thinner oil will flow more quickly but it will not necessarily heat up any more quickly than thicker oil. Thicker oil will heat up just as quickly due to the friction it creates while pumping through the engine.

That's not from me, that's from engineers at bobisthoilguy.

OTOH, thinner oils provide better cooling and have shown to result in lower oil temps at the track. But that's not the topic of this thread!!


-Dennis

[sixthree]

Thanks for all the opinion everyone.

Now question is. Thicker or thinner oil for daily driving during winter? Averages around -20 degrees in my city during winter

ALSO, I have a drop in filter currently in my car. Should I switch back to stock during winter?

[Fastbrz]

Originally Posted by jvincent

I ran 0w20 on the track this year with no issues, other than some relatively high oil temps.

I am definitely getting an oil cooler and may consider 5w30 for track season.

IIRC, the heavier oil will result in more wear until it comes up to temperature, which will take longer. So there's a tradeoff. More wear vs high temp performance.

Don't forget to check your oil pressure.

[Fastbrz]

Originally Posted by sixthree

Thanks for all the opinion everyone.

Now question is. Thicker or thinner oil for daily driving during winter? Averages around -20 degrees in my city during winter

ALSO, I have a drop in filter currently in my car. Should I switch back to stock during winter?

Personally I would run a 5w30 in the summer And a good 0w20 like redline would be fine for the winter. The drop in filter is irrelevant you don't have to change it for weather conditions.