I have a '93 Geo Metro 3 cylinder with 150,000 miles on it.

I found out that the default thermostat is a 195 deg type.

Would I prolong the engine life if I put a 180 deg thermostat
in that car?

It would lower the efficiency, but it would probably prolong
the engine lifespan by running it cooler - no?

Lower oil temp, less wear and tear on the hoses and it would
run cooler in the summer. I can always put a piece of cardboard
over the radiator in the winter.

DoctorBill

Usually the OE stuff is right on the money. Don't think a lower thermostat temp will make a difference. best way to go is keep your cooling system tuned up. :2cents:

To keep the really important parts of your engine cool (the exhaust valves) make sure your EGR system is working. It recycles CO2 into the intake manifold; CO2 does not support combustion, so the engine burns cooler.

My 95 1.0L 5sp uses a 180 degree thermostat. Never had a problem. I just replace them every 40K miles or so as a precaution.

I can't speak authoritatively about the 93s though, as 95 was the first year of a new model redesign.

I think you should use whatever temperature thermostat the specs require. A cooler tolerance will make the car run rich and, I believe, cause the ECM to run in a closed loop. Not good for fuel economy and emissions.

Mike

engine will have less wear at 195 degrees. just stay with stock one.