changing thermostat??

[vncj96]

Ok my wife has a 99 Breeze 2.0 and I just changed the thermostat over the weekend. I know that cars engines and computers need certain things to be able to run at optimum performance and economy. Her car was always running cool and was getting a solid 30mpg avg she also drives 25 miles one way to work on the hwy at 60mph, So after the change she is at 33 mpg and her car is running much warmer and i am sure this is where it should be but would a car running cool kill the mileage that much? Oh, and her old thermostat had completely broken, the u shaped harness that holds the cylinder in place had just snapped, i have never seen or heard of this

[FireRed]

Yes! Not sure if you have noticed how much higher temperatures the late model autos run, higher temps give better all around performance.

[bry2500]

At cooler temps the computer will actually give more gas to the engine because cooler air is denser.The engine thinks that it needs to add more gas, just like a choke on a carb, it is closed at startup but then opens as the engine warms up. So with a warmer engine the fuel consumption will actually be less and will also cause better combustion. But beware too hot is not good for engine life,it causes oil breakdown and can wear internal parts prematurely. There is a fine line in there and car manufacturers are trying to push it.