How can I get better gas mileage for my '03 1500

Trade it in and get a smaller truck or car, other than that keeping the oil changed and a new air filter (I change it every 2nd oil change), and keeping it tuned up. Also keep off "hard" throttle starts. A truck is a truck, I dont beleive that dodge trucks are known for fuel milage. Best of luck.

I dont want to sound "rude", just a quick answer, read it after I posted it. Sorry nothing bad was meant.

I had an 05 Dodge. Got about 16 hwy if I babied it. Going into wind would drop it by 2-4 depending. Pulling trailer unto wind and 11 mpg was best I could do. I sold it. Also Hemi engines start to loose mileage around 80,000 mile mark. I've seen it first hand and heard many people say dame thing. I own a 96 RAM 1500 now and it dies better mileage all around than the 05.

k&n air filter, exhaust, programer for economy, and drive like a grandma...even then, after 100s of dollars you may still only get one or two possibly even 3 more miles per gallon. My record is 22mpgs, drafting behind a semi, cruise control at 65, and larger than stock tires (lower gear ratio than stock). I might could get 23 if i got rid of the stock Y-pipe and fixed my plenum gasket. also lowered truck offer less wind resistance