Does 5W-30 helps to protect the engine?
 

Hi there, Im pretty noob and wanted to know if 5W-30 is better to protect the engine for long run?
I'm in Toronto, and I also heard that it is good to have different oil in summer and winter.
Cause I've heard that Subaru uses 0W20 is only for consumption reason.

PS: No engine mods, planning to keep the car for long run.

Depends on alot of things, yes, no, maybe.

Do alot of reading first

Read your owners manual for cold climate regions.
Nothing wrong with 0w20.

You may want to rethink the intelligence of the 'people' you heard it from.

Seeing as how you describe yourself as 'noob' you probably have little/no track experience. 0W20 will be more than sufficient for your daily driving needs, including the occasional red lining.

Yes, if you drive the car hard, 5w-30 will be better but you will lost some mpg.


I would do 5w30 in the summer & 0w20 in the winter since you are in toronto.

I'm in Sydney, Australia

Winter temps are from 0°C in the winter to 45°C in the summer.

Currently running 5w 30

Thicker oil does come with some issues, your oil/engine temps may rise a little (thicker oil not as efficient at cooling), and they take longer to come down.

I'm going to run 0w 30 next and see if that floats my boat.

My assumptions and thoughts for my oil weights are:
Ambient temps
Start up wear
Current oil temp, engine coolant temp when loaded
Street
Khana
General high rpm runs thru the twisties
Forester OEM cooler to help get temps up and to help get rid of some heat from short bursts of high load

Options may vary

There is a ton of info on the interwebs, research the hell out of it and pick something for your application.

You can get your oil tested, but, unless you know what the results from multiple sampling actually means it's not worth the cost, albeit minimal.

Same conditions, more or less, here in Greece and I use the thickest 5W30 oil (Redline) for my car, for those that want to follow factory recommandations my user manual mentions it clearly, for hard use 5W30 as alternative oil viscosity!

Exactly, this is listed on US manual as well. :cheers:


But op if you use good 0w-20 & have a oil temp gauge it's good enough as long as you monitor the oil temperature. :thumbsup:

Hey OP
I'm in Newfoundland, run 0W-20, have the subaru oil warmer/cooler installed as well as oil temp. / oil pressure gauges. The car is at 33 000km now and I have had the 0w-20 tested (Blackstone labs) at every oil change. Always comes back with excellent results. Drive your car normally, you wont have any problem.
However, extended high rpm running (above 4000rpm) in the summer heat will quickly drive oil temps into the 110 C plus range and oil pressure at redline down into the 40 psi range. Lots of discussion on here regarding this. When I see these numbers, I back off. Basically, if your not tracking or auditioning for Fast/Furious 15, 0w-20 is fine.

The idea behind the thicker oil is typically to maintain good oil pressure at whatever your average temp is when you're using the car the way it's meant to be driven. The track guys who abuse their cars far more than street driven cars use heavier oil because they operate at temps that would otherwise be out of 0w20's efficiency range (or some get oil coolers, or both).

On a street/stock car in Toronto, I wouldn't worry much. Your 0w20 will suit you fine. I live in FL and after 4-5 pulls up to redline in 90F the hottest my oil got was 212F even after sitting at a few lights.

Get oil analysis and see where you are at. I just did it and got a great report on idemitsu 0w20 with a 5k oil change with 33k on her. Report was so good they told me to have more fun with BRZ. Currently tuned with catless header. I do drive many highway miles so that’s the primary reason for the good report.

Although oil analysis will not tell you about what oil pressure you maintain at high revs, except you rev it often so you'll see increased engine wear.
I see you live in Toronto so the best 0W20 you can find probably suits better your ambient temps, but if you thrash it better fit an oil cooler.