2.3 DOHC motor - correct operating temp

[thebanjoman]

I've been running a 2.3 Aerio engine in my 1998 Sidekick Sport for several months now, Daily driving to work, some 70 miles round trip.

 Love the additional power over the 1.8 motor.

 I have a question about engine temp.

 I'm running a dual 10" fan setup using a an aluminum baking sheet as a fan shroud.



 I have a bosch temp gauge and have a 180 thermostat installed.

 I drive 70-80 mph up the interstate and the gauge shows about 170 degrees while running.

 At stop lights it gets up to around 200 but quickly cools down again below 180, even in 90 degree heat.

 What should be the optimal operating temp for the J series DOHC motors??    

 I *Might* be getting worse gas mileage because of the low temps.  

I know the thermostat is working. It's been in a few weeks and i can tell it's opening.