Engine air intake temperature
I was messing around with my scangauge the other day while driving to work and I pulled up the intake air temperature gauge. I noticed that on my commute I was seeing intake air temps around 18-20F higher than ambient. As I slowed down for towns, it would raise a few more degrees to about 23F higher than ambient.
This intrigued me as intake air temperature can have pretty significant effects on power output and also fuel economy. So, on the way home yesterday, I kept the intake air temperature gauge up and watched it as I drove. It was pretty steady and very close to ambient until the engine coolant reached temperatures near the thermostat opening. As the engine maintained that thermostat regulated temperature, the intake air temperature continued to rise until it again was hovering about 20F warmer than what it started at. My theory is the radiator was warming up as the engine opened up the thermostat more and more to keep its temperature regulated. This of course warmed up the air in the engine bay, and the intake is in the engine bay.
Now, I am running a full lower grill block (pictured below). So, I know that that will probably raise the intake temperatures because there is less air flow through the engine bay to keep temperatures down.
However, it does make me wonder how warm that engine bay gets without a grill block on it. In the past I would have said its not important and that once you get going there is enough air flow through the engine bay for it not to matter. However, upon seeing the sensor data from my scangauge yesterday, I am wanting to investigate a bit more. It makes me think that Mitsubishi may have really been on to something by adding the intake duct thingy on the 2017 models. That may have had a significant hand in boosting the power output those few hp.
So, now I am wondering if I didn't have the grill block, what would my intake air temperature be? If someone has a gauge that can measure intake air temp and does not have a grill block, I would love to hear what you are seeing for air temps.
View my fuel log 2015 Mirage DE 1.2 manual: 47.2 mpg (US) ... 20.1 km/L ... 5.0 L/100 km ... 56.7 mpg (Imp)