HyperTech MaxEnergy for the 3.7L V6

[FLYCAV]

Here's the results after testing out my new Hypertech tune.

Before programming, and changing plugs I was getting around 17.9 MPG on the highway with cruise set at 75 on the relatively flat terrain between Cleveland, OH and Ann Arbor, MI. At 65 MPH I would get low 18's (18.2-18.5 MPG).

After installing the Hypertech program (and resetting the computer by unplugging the neg battery cable and putting the key in the on position) I started the engine and let it idle for about 5 minutes. I then headed out for a stop and go trip through town for about 10 minutes, then headed for the highway. I set the cruise at 60, reset the MPG and drove for about 10 miles and got 22 MPG. I got off the highway and got back on going the other direction to head home. This time I set the cruise to 70 and averaged 20.2.

Besides the improved MPG, the improved acceleration is really noticable. A side benefit is that my speedometer is now within 2 MPH of what my GPS reads at highway speed.

In hindsight I wish I would have got a good baseline after changing out my spark plugs before the programming so I could tell how much of the improvement was from the plugs and how much was from the program.

[VegasUnderworld]

Interesting results. Thanks for the report.

Could you list the specific parameters that can be altered using the programmer?

[FLYCAV]

Originally Posted by VegasUnderworld

Interesting results. Thanks for the report.

Could you list the specific parameters that can be altered using the programmer?

The optional parameters are
1. Top speed limiter
2. Engine RMP rev limiter
3. Speedometer/odometer correction for changing from stock tire size.
4. Option to chooose the tune based on fuel (Regular or Premium)

The programmer also has parameters for changing shift points and shift firmness but these parameters are not able to be used on the XK.

[VegasUnderworld]

Is it worth the cost? I would think definitely if it changed shifts points. If it can't even change shift firmness, I'm on the fence about getting one.

Having such a soft first gear on the road isn't a problem, but I'm offroad twice a week. I don't care for that sloppy delay going uphill from a stop. I really want it to be more predictable when I need to hop up and over rocks.

[Nitemare3219]

Originally Posted by FLYCAV

The optional parameters are
1. Top speed limiter
2. Engine RMP rev limiter
3. Speedometer/odometer correction for changing from stock tire size.
4. Option to chooose the tune based on fuel (Regular or Premium)

The programmer also has parameters for changing shift points and shift firmness but these parameters are not able to be used on the XK.

Can also change the cooling fan temp. It ramps it up to 100% and I hear it quite often compared to when it was at stock.

Hypertech told me they don't touch transmission settings on anything Chrysler/Dodge/Jeep.

[07JeepXK]

It's worth the cost if you ever plan to do a gear swap.

[VegasUnderworld]

My last Jeep was a Wrangler with 33's and 3.73 gears and I got used to it, so my bar is set pretty low. I'll never regear.

Would you men mind updating this thread in about a month and report if you're still seeing the fuel savings? If the fuel savings are consistant, that may make the purchase valuable to me.

[FLYCAV]

Originally Posted by Nitemare3219

Can also change the cooling fan temp. It ramps it up to 100% and I hear it quite often compared to when it was at stock.

Hypertech told me they don't touch transmission settings on anything Chrysler/Dodge/Jeep.

I forgot to mention the cooling fan setting.

I only paid $254 on Autoanything.com. It was almost worth it to have my speedometer read correctly, but with the improved acceleration and hopefully long term gas mileage improvement I have no regrets. I put on 15-20k mile/year and if I only got 2 MPG improvement It'll pay for itself in less than a year.

[VegasUnderworld]

Thanks for the info. I may get one just to clear codes and the fuel savings. If it helps in other areas, I'll consider it a bonus. It'll have to wait until after Christmas. Santa robs me every year.

[Nitemare3219]

I'm getting fairly poor MPG, not sure why. Doing 50-55 on flat roads for a few miles and only getting 19 MPG. When I had previously been checking over the past few thousand miles, I would be getting at least 21-22 in the same instance. The only things that have changed are mileage, the programming, and it now being winter. Vehicle was driven for roughly 20 minutes at these speeds before I checked the EVIC (was 45 degrees out). It may be a cold and winter fuels thing as last year my MPG went to absolute crap during the colder months. If I get a chance sometime soon, I'll go back to stock again and see if it fares any better.

I bought this vehicle used at 116k and it's now at 127k. I haven't noticed any obvious performance differences since I've had it, but I have no idea if the plugs are in good condition or completely shot. And I know it can happen. My own mother is driving her 09 Hemi Aspen around with 100k miles and is still on the ORIGINAL plugs...