JPop

The stock 3.8 is no more of a pig than the I-6 motors, just a different rpm range. In fact the stock 3.8 has more hp and torque, you just need to pump about 30% more rpm into it which certainly isn't conducive to off road ventures.

As for performance gains from the Superchips, and with my tests I'm pulling an additional 15 hp based off of improved 0-60mph times, went from 9.84 seconds to 9.14 seconds. Yes, still a pig, but an improved pig where there isn't the option to change mechanicals as many have done with a better cylinder head, and fuel injection on the 4.2L.

The cost/value of the Flashpaq exceeds any performance upgrade for the JK that I am aware of. Certainly there is more power to be had with a RIPP SC Kit, but dollar per hp it's two totally different leagues. Also, squeezing more power out of the 4.2L didn't exactly come on the cheap either as a cylinder head replacement and fuel injection upgrade would lighten your wallet by a couple grand, albeit with better increases.

WNCJEEP

Correct me if I am wrong, but the 4.2 hasn't been used since the mid 80's. The 4.0 came online late 80's with the High Output 4.0 in the 90's. I've had all three in past Jeeps. I agree that the 3.8 minivan moto they put in the JK is comparable to the 4.2 on highway performance but the 4.2 could pull a house down, the 3.8 would blow a gasket screaming over 5k rpm to just get close to the 4.2 in that regard. The 4.0 first edition or High Output is still my favoirte Jeep motor, even when I had a 350 dropped in one Jeep. It is ironic that EPA regs prevented the 4.0 motor use in the JK, b/c I got better mpg out of my old 4.0 Jeeps than I do my new 3.8 JK (granted JK Unlimited is much bigger with 4 Doors and cargo space).

My wife has a 3.5 (honda) motor in her 09 Pilot, which is basically a slightly smoothed out brick and weighs even more, she can't stand the accelration in the JK, the Pilot kicks the poop out of the JK AND gets much better mpg. I don't understand why the JK is sooooo inefficient, which is why my focus is on mpg improvements first, power second.

I still haven't heard any real information on which is better, hypertech econ max or superchips, for mpg. Comments?

JPop

Yeah it's been a while since the 4.2 has been available, perhaps late 80s and the primary difference is in rpm to hit peak hp and torque numbers. Your also spinning a lot more weight with a JK with bigger tires, wheels and axles as compared to what would have rolled off the line in a CJ or YJ. The 3.8 and twisting the motor as you need to certainly isn't conducive to off roading, but I can't remember anyone sticking 5.38s in their CJ to get the revs up 20 years ago either.

While I am not the guy to ask about which programmer works better as my rig was outside the bounds of what Hypertech could deliver, I had way better results with the Superchips in both performance and efficiency. Also, if you really wanted to throw some dollars at it, which might not be so wise, I'm sure you could get some pretty stellar results out of a Diablo Sport Tuner and aftermarket upgrades not supported by Superchips or Hypertech.

szqnva

Based on your info, I'm hoping to see a difference. I have an automatic w/ 35's and 3.73's.

Arcticanalog

are you using the performance tune or the gas mileage tune for those resultS?

Tuto

This are the Feautures that the Superchip offeres-


TUNING

Industry leading Jeep tuning

91-Performance

87-Performance

Towing: Heavy Load Use

Mileage XS: Fuel Economy

CRAWL: High low-end torque off-road mode

All tunes work in 2WD, 4WD-HI & 4WD-LO
OFF ROAD FEATURES

Superchips exclusive CRAWL off-road tune

Tire size calibration of speedometer available on properly equipped Jeeps

Transfer case gear calibration on 2005 and newer Jeeps if properly equipped

Axle gear calibraton on 2005 and newer Jeeps if properly equipped

4WD-HI axle lock with auto-disengage safety feature

Tire Pressure Monitoring System threshold adjust

Real time idle control for running accessories
TRANSMISSION
Superchips Optimized transmission performance standard on all Jeeps

Wide Open Throttle shift points tuned on most Jeeps

Shift firmness optimized on all Jeeps

Advanced transmission tuning product available on newer Jeeps allowing for custom shift schedules, firmness and shift points
ADVANCED ENGINE PERFORMANCE
Rev limiter adjustable on 2005 and newer Jeeps

Speed limiter adjustable on all Jeeps

Throttle body relearn available on newer Jeeps

Spark advance settings available on older model Jeeps

Fan temperature on/off available on Jeeps with electronic fan control

Read & clear diagnostic trouble codes standard on all vehicles

NOTE: Features vary be year, make, model and engine. Search by vehicle in question to find out the details. All Superchips tuning products for gasoline-fuled vehicles are either covered under CARB Executive Order number or are in a pending state. All non-racing Superchips tuning products for diesel-fueled vehicles are on the CARB products in progress list pending CARB testing and approval.