over cool. yes.
an engine is designed to run at an optimum, most efficient temperature.
running cooler than that can cause condensation issues within the engine, which in its turn, can cause corrosion etc.
an engine is designed to run at an optimum, most efficient temperature.
running cooler than that can cause condensation issues within the engine, which in its turn, can cause corrosion etc.
as hot as possible, however yu then get into associated problems with HGF. usually it is between 85 & 95 deg C.
On a track day, you'd like the coolant temp to be around 90C all long (whether it stays there is another matter!)
On normal start/stop driving where part-throttle response is more important, mid-nineties is better.
Emissions are lowest around 100C, that's why manufacturers try to keep temps around there.
But the Octane requirements of the engine increase with coolant temperature. For an 11C increase of the water jacket (say from 80C to 91C) there needs to be a raise of 2 AKI points, if we are to keep the safety margins intact. That could be 2 RON and 2 MON points, or 4 RON points. Quite a lot, eh?
On the other hand, a cold engine (below 70C) should never be pushed hard. Metals need to expand, fluids need to warm up. Let them assume battle stations before applying full throttle!
On a track day, you'd like the coolant temp to be around 90C all long (whether it stays there is another matter!)
On normal start/stop driving where part-throttle response is more important, mid-nineties is better.
Emissions are lowest around 100C, that's why manufacturers try to keep temps around there.
But the Octane requirements of the engine increase with coolant temperature. For an 11C increase of the water jacket (say from 80C to 91C) there needs to be a raise of 2 AKI points, if we are to keep the safety margins intact. That could be 2 RON and 2 MON points, or 4 RON points. Quite a lot, eh?
On the other hand, a cold engine (below 70C) should never be pushed hard. Metals need to expand, fluids need to warm up. Let them assume battle stations before applying full throttle!
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