is there anything i can put on my pickup to increase the fuel mileage by 3 mpg w/o spending over $500. It's an '02 with the 4.7 w/ the 20's.

 

The 20's hurt you a bit, but as a rule of thumb, anything to get it breathing better increases mpg's. That would start with cat back exhaust with a good, solid, higher flowing muffler. Then look at CAI's. Lastly a set of headers (preferrably LT's but at least mid's) would complete the picture.

I know the addition of LT Headers after having a cat-back and CAI in place increased my mpg's by 2-2.5 mpg's by itself. To date, the best mpg mod I've done by far (and the added torque/HP and deeper exhaust note didn't break my heart either)...

 

i do have flowmaster series 40's

 

The search is your friend: https://dodgeforum.com/m_398241/tm.htm

 

this is the picture of the CAI for my truck but i have a 5.7l so urs prolly looks a bit different you can definately get it for less then 500$$ good LUCK

[IMG]local://upfiles/81798/1C64D5C031114C7C8524E5CC7A4F4C92.jpg[/IMG]

 

I am convinced that my tonno cover helped mileage by as much as 1-1.5 mpgespecially on the highway. I got an Extang from summit racing for under 200$

 

Helium balloon on your right foot? Proper tire pressure and wheel alignment. Clean air filter and TB. New plugs by now, unless they've already been replaced a time or two.

 

Highway MPG can go up by about 3 for less than $500 if you make your own tonneau cover and a few other aero mods.

Getting City MPG higher by 3 is much tougher,
but 'HyperMiler' driver behavior,
an electric block heater from a salvage yard,
and a few other mods would at least get you 1.5
perhaps a bit more if you can find lower rolling restistance tires
to use as daily drivers on your 20" wheels from a salvage yard

many mods listed in this long read
that has been proof read and approved
by engineers from Chrysler, GM and Toyota:

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

 

When i got my truck it got around 14.5 mpg. Then I spent $280 on a magnaflow exhaust, $299 on a roll up cover, that put my mpg at 15.5. So then I spent $180 on a trueflow cai (got it used), and it put my mpg back around 14.3. So if I could do it all over I would save my $800, and spent it on something that would be worth it

 

Damn, I don't know what the hell's the matter with me lately. My mpgspeech always used to start with the old tire pressure, tune-up schtick before I talked mods. At least somebody out here is thinking...