I recently got a used 2000 OBW (95k miles). no manual on board. can anyone tell me what the recommended motor oil viscosity grade is? I'm in Wash, DC (HOT summer). I'm guessing 10w40 in the summer and 5w30 in winter, but would appreciate knowing the manual's recommended grade. thanks.

here is my opinion, royale purple or amsoil , good thing about these are changing oil every 12,000mi changing filter every 6,000mi , or castrol gtx 20-w50 ,every 3,000,mi always use a good filter

...10w40 in the summer and 5w30 in winter...

Bingo... according to my wife's 2000 Outback Wagon owner's manual, off the top of my head. If you want to know the exact temp's, I can get them for you.

Hmmm... Changed my own oil this weekend for the 1st time and I thought it was 10w30. Although I couldn't locate the spec in my manual.

 

 

What's the difference between 10w30 and 10w40, and is it bad I put 10w30 in there?

5W-30 is the recommended oil weight. 10W-30 performs the same at running temp.

 

10W-40 for "heavy duty". That means towing or lots of "racing".

Thank you to all who posted replies. I really appreciate this forum and your time.