I currently have a stock feeding 4.0. Im debating a full exhaust with header....perhaps those neon injectors everyone babbles about. Im not sure if I wanna do intake, being that the heat displacement in the engine seems to go against what a cold air intake is designed for. By the time the air makes it to intake manifold I feel it would be just as hot as before .....and I know more air means more fuel to mix a proper air fuel ratio....and im looking for leaner but effective conditions. So I might be thinking too hard on physics that's why I need you guys to give me real life scenarios. 4.0High output preferably but ill accept any input from any setup. I know gears play a big part in this....so, please provide this info.....
1. Engine (specify H.O. if applicable)
2. Tire size
3. Gear ratio
4. Intake / injection / exhaust modifications ....please be specific
5. And provide any improvement or lack of in your mpg department....don't need specifics as everyones driving style is different just if it got better or worse and by how much.


Hopefully this thread will grow and allow every jeep owner helpful information to be able to make proper expensive investments to keep their jeep and not have to sell it for one of those 'green cars'

Thanks!

 

Anyone?

 

Well I got the Spectre Cowl Intake, Magnaflow Hi Flow Cat, Magnaflow muffler with 2.5 pipe. Also did Royal Purple in both differentials. Actually had big difference in mpg and power. Getting 19mpg city. I want to put in the injectors soon

Then I got a lift...with 31" BFG ATs...so no more fun mpg...

 

1998 with newly remanufactured 4.0 ATK longblock, new cooling system, new AC system. new cap,plugs, rotor, wires, coil, yada, yada.

new 235/75-15 Firestone Destination ATs
2" lift
Aw4
3.55
New but stock spec muffler and cat
Stock intake, throttle body, and air cleaner

Drove it with the above configuration for a couple of months, then I put in the neon injectors. I didn't notice any mileage gains, but it starts faster, idles smoother, and seems to have much better throttle response. Worth money in my opinion.

 

1995 2.5, ax5.

worn 31x10.5R15, 3" lift

IAT relocation, CAI w/ heat shield, 4.0 TB, new oem cat, champions, lots of exhaust leaks

26 mpg, no clue on the HP, never touched a dyno. But its a seat of the pants difference from stock.

 

How did you do the IAT relocation with a CAI??
And what exactly does the relocation do...

 

Just tapped it into the intake pipe after the filter, The IAT relocation gives a little more hp and mpg at temps above 80°..

 

mines a 1994 with
4.0
ax-15
"cold" air intake
4.5in of lift on 33in MTR's
aftermarket header, high flow cat and no muffler

i got 15.5 mpg city and then i did the neon injector swap and now i get 17.5mpg city and a better throttle response. 10$ for all six injectors at the jy so it was definitely worth it.