2013 Mustang GT / 5.0. Pretty much what the title says. I was wondering if coolant temps directly or indirectly affect either engine oil or transmission temps.
I’m asking because I just installed a 160 degree thermostat to replace the OEM one and then had my tuner write me a new tune programmed to make the fans come on earlier to take advantage of cooler temps that could be gained from going to a cooler thermostat and am now seeing ECT temps of 180 max when before I would get 218 max.
My question is will having lower ECT temps cause my engine oil or transmission temps to be lower as well? I noticed after an hour of stop and go and highway driving that the highest my transmission temps got to was 181 which is also slightly cooler than what they’d max out at before which was about 190 something.
Not sure if coolant temps affect these things or if it’s just a coincidence.
Your transmission lines go through your radiator and tranny cooler. lowering the temps your fan comes on and lower thermostat will keep the radiator temps cooler and intern the tranny fluid temps cooler.
I’d expect at least slightly lower oil and transmission fluid temps as well. One other advantage is you’ll get less thermal parts expansion/contraction problems, so various gaskets might last longer. You may however discover some downsides to this idea, higher HC exhaust levels may degrade the catalytic converter faster, the spark plugs may tend to soot foul more quickly, so good idea to keep an eye on those. .
Yes everything will run cooler, BUT
30 degrees cooler may seem like a good idea but with the precision machining of modern engines it’s not a good idea.
Most engine wear occurs when the engine is cold. Bearings, rings, and other parts are not fully expanded. These “loose” parts move around and wear faster.
Lower ECT will lower the oil temps. Adding an oil cooler will help keep the ECT temps lower.
Your car does not have an integral transmission cooler with the radiator. It uses a stand alone cooler on the passenger side in front of the radiator. It also has a thermostat for the trans fluid that opens at 185 F.
If your tuner changed the lockup point on your torque convertor to happen earlier, that will lower the transmission temps. I found that at a track day test. 2 of my tunes created higher trans temps than the factory tune.
Makes since about the tranny being cooler since there’s coolant lines going to it.
How much cooler will Engine oil be? Likely not 38 degrees cooler right? There’s no way i know of to monitor oil temps using OBD, only coolant and trans temp.
I’m running long tube headers, high flow cats, intake manifold from a 2018 car, cold air intake, bigger throttle body and 93 octane tune so my tuner recommended lower temp thermostat since 219 is a little high especially since the headers make the engine bay hotter than stock
Likely you are running 190 F oil temps or less. Before I installed a cooler, I’d see 225 max at a track day but 175 on road. I installed a temp gauge. That’s not enough to be concerned about with conventional oil let alone synthetic oil. The Coyote doesn’t heat the oil very much. I have always used a factory t-stat.
Oh, and I mentioned this before…ECT is faked with software from cylinder head temp. There is no ECT sensor.
If that were true there would be a significant difference in the longevity of northern versus southern cars.
I might be wrong (and someone please correct me if I am) but I believe most engine wear occurs within the first 20-30 seconds after a completely cold start, especially if ambient temperature is below freezing. An engine running slightly cooler than factory spec shouldn’t wear out faster correct? And there shouldn’t be any faster engine wear running at 175-180 vs 200-219 right?
Correct
Also correct.
Right.
You might lose a bit of fuel economy, though. Higher temps mean less heat transfer from combustion into cooling and more heat pushing the pistons down.
Maybe a bit more power but this isn’t an old 302 Ford with long passages in the head and upside down cooling (block UP instead of heads down). It is a short runner DOHC V8 with a plastic manifold to insulate the incoming air.