Superchips?

[srmitchell]

Hey guys.

I'm borrowing my dad's superchip tuner for jeeps.

I've tried the 91 octane setup, (with 91 of course)
I've also tried the mileage xs, and 87 tune.

I noticed pretty much no improvement. Has anone else tried one?
I really wanted a mpg improvement, but that's pretty much impossible with the 4.0.

I have a cold air intake, free flow exhaust, and 4 hole injectors in my 2001 4.0.

Just want some opinions! It isn't that great in the 4.7 wj either.

 

[old_man]

A can of BG44K to clean the carbon and fuel injectors is probably about as good as it is going to get.

 

[CherBear]

Agreed, I have yet to see anyone who has seen real improvements from a superchip.

 

[srmitchell]

I'm glad I didn't buy one, because it seems to do nothing. I might convince him to sell it, and put it towards something useful.

91 octane does feel pretty snappy at 1/2-full throttle, but I'm trying to save fuel, not shave 1/4 mile times.

 

[CherBear]

I'm glad I didn't buy one, because it seems to do nothing. I might convince him to sell it, and put it towards something useful.

91 octane does feel pretty snappy at 1/2-full throttle, but I'm trying to save fuel, not shave 1/4 mile times.

For the 350$ those things cost, id much rather spend it on a nice intake or exhaust, or bored TB. You might actually get some mpg gain. Maybe.

 

[srmitchell]

Currently I have-
Iron Rock 2.5 inch cat back
Cowl Snorkel
4 hole precision injectors
Electric Dual fans (no clutch)

I guess next should be a bored throttle body.

I think it's tapped out as far as mpg.

 

[bails85]

wht are you getting for mpgs as of right now? just curious.

 

[srmitchell]

14 Average. The ohc says 14-15 at 65.

I can get 18-19 if I keep it at 55. That's very optimistic, and hard to maintain.

Btw, 4 inches of lift, 32's, 4.56 gears. No roof rack.

 

[1990JEEPXJ]

weird. i get about that mileage with 33's and stock gears. stock intake and injectors as well.

 

[Jeepguy03]

Superchips are useless on a 4.0L. Maybe a duramax or something that is more computer controlled. In some cases I've even seen them make 4.0L's run too rich.

As for MPGs...
-check all your O2 sensors, they are only good for around 100k before they get lazy. They can be bad without throwing a CEL
-how are your plugs?
-run fuel system cleaner through it like stated above
-whats your tire pressure?
-heavy bumpers?

I'd start with a tune up. Obviously a lifted jeep with heavy bumpers won't get great mileage, but you could do a bit better.

Just curious, what RPMs are you running at 65 vs 55?

 

[srmitchell]

First off, humboldt county, we get horrible quality gas.
2nd, lots of hills.

Plugs are only 5k miles old.
Upstream O2 sensors are 6k miles old.
Tire pressure is 34 psi.
Steel front bumper, sliders, steel rear bumper, roll cage.

At 55 I believe it does 2100 rpm. 65 it is 2500.

 

[Jeepguy03]

First off, humboldt county, we get horrible quality gas.
2nd, lots of hills.

Plugs are only 5k miles old.
Upstream O2 sensors are 6k miles old.
Tire pressure is 34 psi.
Steel front bumper, sliders, steel rear bumper, roll cage.

At 55 I believe it does 2100 rpm. 65 it is 2500.

Well at those speeds your engine is still in the powerband. I'd say weight plays a big factor, but more so the issue of horrible gas. I assume in CA they use ethanol in the gas. I did a test where I drove on the same stretch of highway, completely stock XJ, everything else the same except the gas. My first trip I got 18 mpg with 10% ethanol gasoline. The next time I used gasoline with no ethanol content and got 22 mpg. I'd definitely run some fuel system cleaner through it if you know the gas isn't that great. I can only imagine what poor quality gas does to your fuel system. I try to run some in mine every couple tankfuls, since ethanol is corrosive.

 

[srmitchell]

I'm also in the north part of the state. All gas is barged in, so it probably has water in it too.