low temp thermostat

There were very good reasons why the engineer who designed your engine and it's cooling system specified the temperature of the thermostat, unless you know better, stick with the manufacturer's recommendation.

A thermostat that opens at a lower temp than the computer is designed to operate at, can actually be harmful. Wear will be increased if the computer stays in open-loop mode because the coolant isn't up to temp, the richer mixture during warmup mode can wash oil off the cylinder walls.

Despite what many people seem to think, running a lower temperature thermostat will not give you extra margin against overheating- because an overheated engine will have already opened a high temperature thermostat anyway.

Running at the higher end of the normal temperature range (195 to 210 or so degrees farenheit) reduces cylinder wall wear and improves combustion efficiency. Running at the low end (160 farenheit) can help some engines get more total power by allowing more aggressive timing and compression without detonation. In general, the hotter the better (up to a point) for engine longevity and efficiency.

Yes, hotter may mean more efficient, but it also means more NOx compounds, which will mean you're more likely to flunk your emissions tests, if required.

Remember that air is mostly nitrogen >Joseph Fox wrote:

Getting lots of opinions, aren't you? Heres mine: I agree with mark walsh that factory engineers knew what was needed. Low engine temps accelerate engine wear. The small performance difference (if there is one) is more than offset by the cost of engine parts and worn engines. Also, using a lower temp t-stat has NO effect on whether you can use plain water or anti-freeze, thats just plain wrong. Nox emissions are caused by high combustion temps. Lower t-stat temps may have a negligable effect on their production. If your emission system is working as designed, your car will pass emissions tests with the proper t-stat. My 2cents

In the great scheme of things a thermostat is not going to make much difference in engine wear. The temperature difference between thermostats is not nearly as much a starting an engine on a cold morning and then cruising down the highway an hour later at 80 mph.

If you ever try to flush an engine running with a high temperature thermostat or try to limp home with a cooling system that won't hold pressure you will find that it will boil before the thermostat opens because there are hot spots in the block that are much hotter than the temperature at the thermostat.

This helps alot. Thanks a load.