Originally Posted By: Lorenzo
OK, I suppose I meant read it carefully and completely. My fault for not being clear.
In your first post you describe your usage as severe service. In the owner manual for my '02 WRX with the same engine as yours, it recommends up to 20w50 for severe service. I assume your Legacy manual has similar recommendation.
Originally Posted By: 2002 WRX Manual
SAE viscosity number and applicable
temperature
1) 5W-30, SAE 5W-30 preferred
2) 10W-30, 10W-40
Recommended grade and viscosity
under severe driving conditions
If the vehicle is used in desert areas, in areas with
very high temperatures, or used for heavy-duty applications
such as a towing a trailer, use of oil with
the following grade and viscosities is recommended.
API classification SJ or SH:
SAE viscosity No.: 30, 40, 10W-50, 20W-40,
20W-50
Hi, thanks for the information. It must be me who failed to read completely. Let me counter check with my manual again.
With regards to the severe driving condition, how do we define "very high tempreature area" and "heavy-duty application (beside towing)"?
