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Old 02-01-2023, 09:15 PM   #39 (permalink)
EcoCivic
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Quote:
Originally Posted by Christian View Post
Thanks for the heads up, 47-48mpg would be amazing for me, but since I'm almost exclusively short city drives, I feel that EOC would be a great method to squeeze extra efficiency out of my civic. I really want to wire a killswitch to the injectors, because I hate fiddling with the key and having my radio shut off.

My civic sits right around 193-197 degrees Fahrenheit when warmed up and driving around. I will definitely need to figure out at which temperature my fans turn on, in order to ensure my fuel economy & fan efficiency don't counteract. Hopefully, I won't need to worry too much, as our weather isn't great most of the year, and I rarely run A/C.



This is a great idea, I saw mention of this in another thread, and it definitely would be helpful to be able to watch my fans so precisely. Who knows if I end up doing it though, as mentioned, I hate messing with wires.
A killswitch would be a good idea if you plan on killing the engine regularly, it's much easier and safer than messing with the key and would save substantial wear on the ignition switch in the long run. But first, I would do some testing to see if killing the engine rather than letting it idle is significantly beneficial for your driving style. For what it's worth, when I tried EOC, I saw a slight drop in my average MPG if I killed the engine when it was still cold, presumably because doing so significantly delayed warmup. By a narrow margin, I seemed to get the best results with EOC by killing the engine only after the coolant was fully warm, but we're talking about +/- about 1-2 MPG, so easily within testing variance.

193-197 degrees coolant temp is about 10 degrees hotter than I see with an OEM thermostat, but still perfectly fine. Perhaps someone installed a hotter thermostat. The OEM fan switch is supposed to activate at 93 degrees C (~199 degrees F) according to the service manual, but since the fan switch is on the thermostat housing and sees cooled return coolant while the temp sensor sees hot supply coolant, that seems to translate to the fans activating at about 204 degrees F indicated coolant temp on my car. So as long as you aren't seeing 200+ degrees, the fans shouldn't be on.
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Christian (02-01-2023)