Thats the bumbest thing I have ever heard how will oil changes, transmission adjustments, Dual Exhaust, andKeeping the air filter as clean as possible decrease mileage? and here is the math for you.
I spent a total of $300 for the plenum kit, 180* t-stat, plugs, wires, cap,rotor, and thecai. I started at 13 mpg and get a solid 18mpg now but just recently got 22mpg but figuring on 18mpg and paying 2.89/gallon it takes me 4854 miles to pay for the mods/repairs so I call it a savings of $300 per oil change. another oil change= throttle body 2 more oilchanges after that= exaust.
AND DONT GET ME STARTED ON PAYING FOR A HYBRID!

 

Jenny,
I would not spend the money on a name brand CAI as you will not see any benefit over vs. an open element air filter like the 14" round Mopar Performance one sold for $70.00 at Summit. Don't get me wrong, they both will help, but why spend the extra $200.00 and get the same performance?

A new high flow catalytic converter and Flowmaster 40 muffler will help get the added air flow from the open air filter out of the motor and consequently help with performance. Also adding a quality set of shorty headers will help with flow too.

I would also recommend changing your plugs, wires, cap and rotor. Get the brass contact ones, and the 7.5mm Mopar Performance wires. Don't skimp, cause changing them out is a bitch and you only want to do it once. A 3" body lift makes a world of difference in the accessabiltyof the distributor BTW (maybe your not in to making your truck taller, but if you are, there is another good reason supporting a body lift).

A 50mm throttle body likea Fastman will alsohelp get air into the engine and help with performance.

Now the mith......performance add on components likeI just listed will reduce your milage......not true!

By allowing your engine to breath better, you can see substantial gains in MPG. The problem is, most guys installing stuff like that, can't keep their foots off the skinny pedal, and since they add performance by adding increased air flow, your engine uses more fuel to counter the increased air flow and their milage goes down.

So if you can learn to keep your foot out of the accelerator, these mods will help MPG tremendously.

 

The fastest and easiest mods to improve MPG
are
changing to low rolling resistance tires (good for up to 2 MPG gain)
and for city driving...an electric block heater (good for 1 MPG gain)



There has never been a careful scientific test
that showed that aftermarket air filters or inlet systems
improved MPG
but the myth continues
because 50% of those that do bad tests
will randomly show a MPG gain on their next tank of gasoline.

Both the SAE (society of automotive engineers)
and US EPA (environmental protection agency)
have tried to educate the public on this
but every year millions of $ are spent seeking higher MPG with intake kits.
The EPA has had an 'open invitation' for 17 years
to test air intake kits for MPG gain but none have ever shown a gain
and most aftermarket companies are afraid to do the test.

Much more on two dozen more mods that do give
'real' MPG gains
in a very long read:

https://dodgeforum.com/m_447500/tm.htm

 

What's an electric block heater? Surely yer' not talking about the cold weather thingies.

 

Yes, a plain old low technology
$65 electric block heater for the coolant
so that the engine will reach
"fully warmed up"
faster and get better MPG
on the first 6 miles of each trip
like the above graph from the Florida Dept of Transportation shows.