The PCM's memory is flashed with the tune it is not going anywhere.FLORIT said:Also, I would think, if you ever disconnected the battery, your PCM would reset to defaults and you'd lose the "Mail Order Tune". (Don't quote me on that, I may be wrong.)
Since the early 80"s, if the A/C is off, the fans do not come on until 228. All together different if the A/C is on. Do not be alarmed at 228 degreesmistermike said:I've done a fair amount of observing the ECT while driving. At speed, the temp will settle to around 192 to 194 depending on outside temp. Idling, it will climb to 228 before the low speed fan kicks on. That's a little too wide a swing for me. Less temperature variation is good for the engine regardless of your desired setpoint. I suspect the factory engineers allow it to get that high to avoid frequent cycling of the fans, which some may find annoying, and will degrade economy slightly, due to the alternator drag. I personally would favor a lower fan trigger, even with a stock thermostat.
Acctually installing a 160 t-stat will do jack squat without reporgramming the fans. If the fans dont cool the system until 215+ degees then it doesnt much matter when the t-stat opens up.dms said:To start, I do not thinkg the coolant system is large enough to keep the coolant temp at or around 165 degrees on a warm day. There are reasons for 195 degree thermostats. the oil last longer and is better for the engine. Witout reprogramming other items, you can stay in open loop longer, and create other types of emissions and contamination probelms. Granted it is important to lower the temp if you are significantly pumping up the hp. But just remember one of the basic laws of physics: with every action, there is an equal reaction. You should think about the ultimate goal you want with the vehicle.