How do you get better fuel economy in a 2001 dodge ram 1500?

Not much you can do beyond making sure the tires are running at the correct pressure, the air filter is clean, you are not carrying around cargo you need not carry and driving for fuel economy. No jack rabbit starts, driving the speed limit and not above. You can install a cold air intake system with free flow filter but you will never recoup the cost of the system unless you drive this vehicle for years. Even that may only provide a 1/2−1 mpg increase. True dual exhaust with headers will help but then again you have to drive the vehicle for years to recoup the cost of installing the headers, mufflers, pipes, and an additional catalytic converter needed.