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Old 12-01-2012, 06:07 PM
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Quote:
Originally Posted by fmugur View Post
Jeff, why dropping the temperature to that range will be bad for the engine?
There are engines that operate in that range.
Is it bad for the engine or the engine does not run as efficient as it can?
Bad is too strong a word. I like modern engines running hot. They get to temperature sooner, and thus wear less. It burns the deposits out of the combustion chamber better, keeping it all cleaner. Also, it is slightly more efficient. And the oil gets hot enough to burn things out of it that we don't want in there. The downside is that the oil is stressed more, but we are now running much better oils than a decade ago, and they stand up well, so I don't worry about that aspect. I don't worry about modern engine operating temperatures, as I haven't seen evidence of any increased wear related to those temperatures. Note that one of the biggest issues relating to the X5 (the entire CCV discussion) is due to too low a temperature, not too high a temperature.

There is a side discussion about changing the thermostat opening temperature (the lower setpoint) and how it relates to absolute engine operating temperatures. Traditionally, putting a colder thermostat in an engine changes when it opens, but it doesn't increase the cooling capacity, as that is limited by the cooling system performance. Once the thermostat is open, it is open. It appears from Civ's measurements that in low-load situations he is seeing a reduced operating temperature (as I would expect), as the cooling system is not at its own limit yet.

I don't want to take anything away from what Civ has done, as it is pretty interesting, and I admire his approach.
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