My ct is completely modded out with exhaust, coilovers, under bracing, strut tower braces, quantum solenoid, 18x9 wheels, etc and it doesn’t decrease my gas mileage. I actually am still getting 45 consistently driving freeway and streets 50/50. I’ve put in $16,000 of mods so far, and it’s not a waste of money if someone enjoys it. After all, the ct sounds like **** without an exhaust when accelerating hard. At least it sounds like a car now. To OP, if you have an questions or anything about this car regarding mods, ask me on Instagram @clean__ct. You can check out the car and I can give you some good beginner mods since I myself got the car 8 months ago at age 19.