Subaru WRX STI Owner's Manual page 546

Alternative engine oil
If the SUBARU approved oil is unavailable, the following alternative oil can be used.
NOTE
. Each quantity indicated here is only a guideline. The necessary quantity for replacement may differ slightly depending on
the temperature and other factors.
. In choosing an oil, you want the proper quality and viscosity, as well as one that will enhance fuel economy. Oils of lower
viscosity provide better fuel economy. However, in hot weather, oil of higher viscosity is required to properly lubricate the
engine. The following table lists the recommended viscosities and applicable temperatures.
. When adding oil, different brands may be used together as long as they are the same API classification and SAE viscosity
as those recommended by SUBARU.
Oil grade
API (American Petroleum Insti-
tute) classification SN with the
words RESOURCE CONSER-
VING
or
ILSAC (International Lubricant
Specification Advisory Commit-
tee) GF-5, which can be identi-
fied with the ILSAC certification
mark (Starburst mark)
I n f o r ma t i o n P r o v i d e d b y :
SAE viscosity No. and
applicable temperature
5W-30 synthetic oil is the required oil
for optimum engine performance and
protection. Conventional oil may be
used if synthetic oil is unavailable.
*: If 5W-30 synthetic oil is not available,
5W-40 conventional oil may be used if
replenishment is needed but should be
changed to 5W-30 synthetic oil at the
next oil change.
12-5
Specifications/Specifications
Engine oil capacity
STI:
· Adding the oil from L to F level:
1.1 US qt (1.0 liter, 0.9 Imp qt)
· Changing the oil and oil filter:
4.5 US qt (4.3 liters, 3.8 Imp qt)
· Changing the oil:
4.2 US qt (4.0 liters, 3.5 Imp qt)
Except STI:
· Adding the oil from L to F level:
1.1 US qt (1.0 liter, 0.9 Imp qt)
· Changing the oil and oil filter:
5.4 US qt (5.1 liters, 4.5 Imp qt)
· Changing the oil:
5.2 US qt (4.9 liters, 4.3 Imp qt)
CONTINUED