My N/A car engine's normal operating temp
in the ~185 F - ~205 F range. Being somewhat "old school", this suggests to me that the thermostat spec would be ~195 F (90 C = 194 F).
I wasn't able to find a definitive single-number T-stat temp spec. However, the '07 Forester service manual section on the thermostat (see attached) provides the following info:
Starting temperature to open:
Non-turbo model: 80 — 84°C (176 — 183°F)
Turbo model: 76 — 80°C (169 — 176°F)
Non-turbo model: 95°C (203°F)
Turbo model: 91°C (196°F)
Frankly, I'm not quite sure how a thermostat temp spec is defined these days ("Start to open"
? Between "start to open"
and "fully open"
?). If the spec is based on "start to open", then it looks to me like the reference '07 non-turbo / turbo t-stat specs are 180 F (82 C) / 172 F (78 C).
If the spec is based on something usefully in-between "start to open" and "fully open", then it looks to me like the reference '07 non-turbo / turbo specs are 194 F (90 C) / 185 F (85 C).
FWIW, I'd prefer this definition, as I'm used to a thermostat setting being a target value. However, I also appreciate that mechanical automotive thermostats can only react to coolant temperature, and don't really control it.
Based on the "start to open" definition above, the 160 may be OK in a turbo motor operated in generally warm-to-hot climates or conditions. However, I'd still caution against putting one into a current non-turbo motor, and using a 160 in a turbo motor in cold conditions may not be beneficial.
Jim / crewzer