Mpg/power gain suggestions 99 5.9 magnum

[Redneck760]

Lookin for some tips or suggestions from some elder ramers,
Iv got a 99 1500 5.9 magnum, she's got 190k on her, 35s, 4" lift, with only a AFE cold air intake. I'm currently getting around 9mpg city. Now I know old 5.9s are very much not fuel efficient, but Iv read some people are getting around 15mpg. Was thinking of getting electric fans, AFE throttle body spacer, and a flash paq programer. Iv heard a lot of negative feed back on the tbi spacers as well as the elec fans. Basically. It's it worth the upgrades, or should I just accept the 9mpg?

 

[MoparMagic'00]

one big question.. what gears are you running with those 35s? 4.56s are recommended to go to a basic stock tire size of 265s with 3.55 (stock specs) I will probably go with 4.88s or dana 60 swap for mine..

 

[dodge dude94]

Psh, I'm getting 9 mpg city and I'm stock running 33s. I say be happy with what you have because it won't get much better.

 

[Merc225hp]

As posted gear's will help a lot, but not a cheap investment. The better you make the motor breathe the more efficient it will get, thing is its not cheap to mod these motors and you will never get your money back out of those parts via better mpg.

TB spacer = waste of cash
SCT tuner = Big plus for your year truck
Elec fans = If I thought anything was to be gained I would have had them on long ago.

Part you could look at installing

A good set of headers, IE Gibson, JBA, like that not cheap.
A good flowing full dual exhaust.
Mopar M1 intake.
Double roller timing chain set.
1.7 roller rockers.
A full tune up with quality parts.

 

[BBartow]

Good info here. Just want to mention 4.56s and 35s won't bring you back to stock, 4.10s will. These trucks were under geared from the factory so that's why we recommend them.


Sent from my iPhone using Tapatalk