[PTCruisin808]

I have a 04 Platinum Limited Edition that I just got. I have a K&N filter, alignment just done, new tires, new Magnecor wires, and new Iridium spark plugs. I am only getting about 220-230 miles a fill up. So, what is that? About 15 mpg. 3/4 of the time I am driving I am on the freeway. So, what's up with that? I don't drive hard, I try not to go above 3000 rpm, but I need to going up hills, otherwise I'll be going 40 mph on the freeway. This car is a brick. I had a Lexus GS300 before this that got better gas mileage, which according to the EPA, I shouldn't be. Is there anything else I can do to improve my mileage? I have a turbo lite, should I be using regular gas to improve my mileage? Thanks.