Using 5W20 in a 5W30 application

[mechtech2]

You change it twice a year?
A viable option is to use the 20 in the cold months, and the 30 in the warm ones.

Using the 30 year round is my first choice, unless you have specific problems.

 

[subiedriver]

Our bulk oil at the Kia dealer I work for is 5w-20. This goes into everything that comes in for an oil change. I haven't seen any blown up motors yet. I would absolutely not put that oil in my Subie though, no way!

We only use 5w-30 if the customer makes a request for it.

 

[oggb]

Did this in my Mirage. It worked, even when it was REALLY hot out. Don't think I'd do it with a vehicle I couldn't afford to repair, though.

 

[RAYSGV]

Do you think i would be okay with the RL 0W20? Would i benefit from trying the 0W30 from my current oil?

Originally Posted By: CATERHAM
Originally Posted By: RAYSGV
Specs on the Redline 0W40 are quite impressive. I'm leaning towards it. I can get it for 43.99/gallon in my area.

No it's too heavy for you're application.
Their 0W-30 is more appropriate or even their VII free 0W-20.
RL 0W-20 is really a light 30wt oil and will be heavier in service to a typical 5W-30 like M1 since it does not shear.

Anyway you're getting ahead of yourself since RL is not recommended for new engine break-in.
Another oil to consider for your new engine is Quaker State Defy 5W-30. It has a higher ZDDP content.

 

[JackB1]

I listed a link to an interesting study of oil weight and indications that auto manufacturers have moved to low weight oils to help them with the CAFE mileage standards possibly sacrifing engine life in the process.
http://www.machinerylubrication.com/Read/518/motor-oils