[mbehr]

I have an '07 Wrangler 4dr with the 3.8L V6 and automatic. I'm looking to reprogram the ECU to improve the gas mileage and automatic shifting. I'd like the Forum's consensus on the best ECU reprogrammer. Hypertech, Superchips, Edge, and BullyDog come to mind. All make great and wonderful claims but what real world results do we have?

[Prot]

It's a Jeep. It's not a Prius. If gas mileage was a concern, you bought the wrong vehicle. Driving style more than anything will have an effect on your fuel economy. Going past 65 mph drastically increases fuel consumption. I and a few others have documented this. Someone decided to not go past 55 and got their fuel economy up to 24. There isn't anything on the market that provides any sort of realistic increase in power or torque for the JK yet, however, hypertech does make a programmer that allows some adjustments, the most useful of course, is the ability to adjust your speedometer/odometer to compensate for different tire sizes. I'm merely stating facts here. Jeeps, particularly Wranglers, have never been known for fuel economy and the JK is no exception. People report anywhere from 12 to 26 mpg.

bone stock I got 19 mpg, that is 4.10 gears, 18" wheels, and 32" tires
I switched to 17" wheels, 35" tires and stayed with stock gearing for 12 mpg
I regeared to 5.13 gears and got all of my lost power back and then some and get 17 mpg

[mbehr]

I'm only interested in technical answers and not a lifestyle lecture. This is not my first Jeep; actually my third. I do choose to modify as much as my pocket book and freetime will allow. I am to conclude from your post that you have not reprogrammed your ECU but have heard that Hypertech does make one. Thank you for your input. Next.

[igofshn]

Read prots post again. He told you that nothing on the market will give you better mpg's. You think he is making this up??? Nothing out there will help you with mpg's except your driving style. If you don't like his answer then don't ask the question.

[Seabass004]

Originally Posted by mbehr

I'm only interested in technical answers and not a lifestyle lecture.* This is not my first Jeep; actually my third.* I do choose to modify as much as my pocket book and freetime will allow.* I am to conclude from your post that you have not reprogrammed your ECU but have heard that Hypertech does make one.* Thank you for your input.* Next.

Easy.....you asked for opinions, you got one.* What i read was Prot doesn't think it's worth the money.* No reason to get sensitive.

[Warlord2]

Hypertech will give you a gain...I believe any good aftermarket computer chip will give some gain to a N/A engine and even more for a F/I. I am actually getting the hypertech just to get my odometer strainghted out and am hoping it will give me that extra umf to get over some of these hills around here.

[mbehr]

Since I am keeping score for the different reprogrammers-

Hypertech - 1
Unichip - 1 (from a search of this forum)

I'm hoping to get good or bad responses from those who have tried the reprogrammers to narrow this down to a single manufacturer that would most benefit those who wish to do as I intend to. Mileage, low rpm torque, and improved automatic shift quality are the criteria.

Thank you for the technical responses.

[Prot]

FWIW, my transmission shifts better since regearing the differentials. It shifts better than it did when it was bone stock right off of the lot.

I did provide technical data in the form of fuel economy figures. My speedometer and odometer are adjusted for my modifications via reprogramming.

Unichip has been on the market for some time. Nobody on this forum to my knowledge has reported any measurable gains in performance or fuel economy using it. The hypertech hasn't been on the market as long, and I haven't seen people chime in with it. The programmer I used to correct my speedometer/odometer does diagnosticss and adjustments for tire size and gear ratio changes. It was one of the first on the market to offer the ability to adjust for these factors. I and a few others on this forum have benefited from it as I have loaned it out to forum members.

I would like to think that your caustic response was misinterpreted and something was lost in translation from words coming out your mouth to text on the screen.

[nota4re]

You are mistaken if you believe a programmer will increase fuel mileage on a modern FI motor. Short lesson on engine management: The majority of the time you are driving, your ECU will be in closed-loop mode. Closed-loop means that the ECU is pulsing the injectors and then polling the O2 sensors in an attempt to achieve a perfect 14.7:1. You must note that O2's are only reliable to report that they are either above or below 14.7. The ECU simply "walks the fence" and, in doing so, keeps the a/f right at 14.7:1.

Regardless of vehicle or ECU, tuners cannot change the operation of closed-loop mode. Say, for example, a tuner wants to run a little leaner.... a target of 15.5:1, for example. It can't happen. Again, the issue is the O2 sensors. You CANNOT have a target other than what the O2's are capable to perform.

So, at best, the tuners can change open-loop mode operation (the ECU reverts to open-loop under heavier acceleration) and the tuners have some capability to play with timing.

But, the reality is that the OEMs do a damn good job of closed loop. advancing the timing a bit would yield slightly better mileage - but you risk introducing pinging.

In brief, the answer you got back from the first response was accurate. Driving habits will be your best bet to improve fuel mileage.

[ChicagoGuy]

Prot's repsonse is actually the best response you are likely to get regarding programmers.

I use LT1 Edit religiously, after ever minor changes on the Corvette, so it's not like I'm anti-programmer or anything. But with the stock motor in the Jeep, there is little if anything you can do with any of the programmers on the market to make a noticeable fuel mileage increase.

IF you had added a bunch of aftermarket parts, from headers on back and also a full intake, you in theory could optimize a bit more than stock, and for that, I'd go with Unichip based on what I've seen/heard. But for a stock motor, nothing really on the market is going help.

Sorry it isn't the answer you wanted to hear, but it was the correct one.

[dmerc]

So no-one makes something like a Power Commander, used on motorcycles?
I'm not here to argue, BUT, fuel injection CAN be controlled, O2 sensors CAN be bypassed, and I can vary the mileage by 10-15 mpg on a liter bike, without changing riding habits.

[liquids]

Originally Posted by igofshn

Read prots post again. He told you that nothing on the market will give you better mpg's. You think he is making this up??? Nothing out there will help you with mpg's except your driving style. If you don't like his answer then don't ask the question.

Prot's answer was his opinion, not fact. So's your contention about mpgs. The OP acknowledged Prot's answer then asked for more.

Originally Posted by Prot

I would like to think that your caustic response was misinterpreted and something was lost in translation from words coming out your mouth to text on the screen.

"Caustic" is a misinterpretation in itself, IMO. His response sounded pretty level-headed and he asked for the next person's input.

Sometimes this place needs a schoolmarm.

As far as the subject matter, some people would choose to regear to change the driveability. He, however, wants to change the programmed shift points of the auto trans. Seems reasonable to me.

So, has anyone used one the mentioned products to change shift points?

[ChicagoGuy]

Originally Posted by dmerc

So no-one makes something like a Power Commander, used on motorcycles?
I'm not here to argue, BUT, fuel injection CAN be controlled, O2 sensors CAN be bypassed, and I can vary the mileage by 10-15 mpg on a liter bike, without changing riding habits.

Hypertech and Unichip both make something like this, but as far as I can tell, they mostly work at WOT or by adjusting like you are describing for premium fuel, which then just offsets the cost (i.e. you pay more to run a tank of premium at the better MPG over the cost of a tank of regular).

Technically, they do WORK, just not in a way that makes them useful for this particular motor, at least as it relates to MPG. Think of it this way, if you are getting 90+ MPG on your bike, 10 MPG is a 10% improvement. And you don't have anywhere near the rolling resistance or aero drag (or driveline power loss) the Jeep does. So even if we got 10% on 16 MPG, that's now 17.5 MPG.

For changing shift points, they all work about the same. I'll spare the lecture on getting a real auto trans valve body upgrade instead (although that is what I would do) . Borrow someones for a quick upload of a new stock program with different shift points, or buy the cheapest one if just being able to change them is all you really need.

[BeerMonkeY]

the ripp supercharger system claims in increase in mpg under normal driving. i also go t a small increase after getting a custom exhaust done

[igofshn]

Originally Posted by BeerMonkeY

the ripp supercharger system claims in increase in mpg under normal driving. i also go t a small increase after getting a custom exhaust done

Ripp as well as other companies CLAIM alot. Your gas increase is probably gone now, because your computer has had time to reprogam itself and overide any increase. Same thing with intakes, as soon as the computer figures out more air is coming in, it wil compensate and run normal. Here is alink that describes what I am talking about.

http://www.omninerd.com/articles/Improve_MPG_The_Factors_Affecting_Fuel_Efficiency