If you're looking to drop IAT (Inlet Air Temperatures) by up to 42 degrees Fahrenheit, the Mishimoto Intercooler Core is a great upgrade! This larger Intercooler allows your Civic 1.5T, Si to not pull back engine timing which reduces engine power levels, especially in the summer when the factory Intercooler becomes completely heat soaked after short while of spirited driving. "Heat soaked" refers to the surface of the intercooler being too hot, and not cooling down the passing air enough for it to return cool back into the intake manifold.
This is a direct fit Intercooler Core for the 2016+ Honda Civic 1.5T and Si - the piping kit is not included; you can re-use your factory piping. The Mishimoto Intercooler Kit with their piping kit is also available, and would be recommended if you are Full Bolt On (FBO), or have extended periods of spirited and/or track driving as the Silicone piping is more robust than factory Rubber piping, and keeps the air flowing through smoother and cooler, with less chances of cracks over time.
Not significant, but max power gains of 3whp, and 8ft-lbs of torque on the stock tune can be expected. We have the Mishimoto IC (full kit with Piping) on our Blue Si, as it's FBO and sees the track. Since install, the car has never heatsoaked!