My '15 Mirage is a month old. I have done two modifications to help increase power, mileage and acceleration. First, I changed the restrictive stock muffler with a free-flow MagnaFlow. This did NOT increase interior noise but let the exhaust get out without taking power to PUSH it out. Significant power increase. Secondly, I modified the restrictive stock airbox so it could be directly connected to a K&N and a 5" polished Stainless Steel spacer to get the air filter AWAY from the radiator and the hot air coming through it. Now it is off to the side and brings cool air into the engine. Again, this if Free-Flow so mileage, power and acceleration are all DRAMATICALLY improved. What will mileage be? Not sure, but I don't have to depress the accelerator hardly at all now to get the vehicle moving fast quickly. That will translate into better mileage. See how clean this set up is with attached picture. The Mass Air flow is connected, so the engine computer system remains happy. It just has access to more and cooler air than before. I'm thinking about posting this as a kit for sale on eBay for a bolt on improvement for the new Mirage.
What do you think?
Enjoy the pictures.