Possible issue with car

Hello everyone I believe that I have a issue with my car. My gas mileage is terrible. Just completely awful and yes I know these cars aren't great on gas but what I'm getting is not every pickup truck mileage. A full tank of 92 octane Shell V Power gas will only last me about 150ish miles. I do have different driving styles though. If I'm beating the hell out of it I get about 130, 150ish is relaxed but some spirited driving included, and 180 if I just baby the thing and cruise at 3500rpm all day. The plugs, wires, and coils are new, maf is cleaned, no check engine lights, and I did the 20 stomp reset. When I first got the car I was getting 230-250 to a tank and still having fun driving the car. Things started going downhill once I started doing basic maintenance like changing all the fluids. I don't believe that anythings wrong since theres no CELs or leaks.



Also car in question is a 6 speed GT 2007 Mazda Rx-8 with 54k miles and solid compression as of august.



Mods done to the Car are: Lighter wheels, went from all season tires to summer, on powertrix coilovers, and sohn adapter. I've read somewhere that summer tires have a high road resistance which affects gas mileage.



I searched around and I saw a thread close to mine and someone mentioned a clogged cat. I looked up the behavior of a car with a bad cat and my car does not act anything close to it.



Sorry if that was a lot to read but I just want to be through so I can avoid the first " have you done this or that" replies. Thank you for reading.