Originally posted by DelSolSIinMD
The best I've ever done is 35 in my 94 Si... but lately, the best I'm doing is around 30. The car never totally warms up in the 20-degree weather we've been getting. It will only get all the way up to under the halfway point if the heater is off - which, of course, is unbearable. Otherwise it hovers somewhere just between the top of the "C" and below the first hash mark. So with the car not reaching peak operating temp., my mileage must be suffering.
On a side note, anyone know why the car won't reach and maintain normal operating temp.? I just changed plugs, wires, flushed the coolant, changed oil and filter, and all belts/water pump - all before this latest cold streak. My theory is that the cold air is chilling all the cooling system elements - block, hoses, heater core, etc. So when the car runs with the heater on, this ultra-cold coolant is running through lots of cold piping, and takes forever to warm up. I bet if I ran it long enough, all the various pieces would get warm enough and it would hold a steady temp, heater on or off. Anyone know for certain?
You need a new thermostat bud. It's been about 15 degrees here lately, and it takes about 5-6 minutes for it to warm up.