[JeepEngineers]

Originally Posted by Unlimited04

my dad's commander has the 4.7L V8 and gets around 8 to 10 mpg. it is serviced regularly at the dealership. his previous WJ with the same engine got 25mpg on the highway. is the extra weight of the commander to blame here? what is Jeep doing to improve fuel economy in the commander, WK and all other vehicles? A suggestion - diesel with 30mpg available in all models.

Weight and aerodynamics are definately a factor - the XK/WK are much heavier than a WJ, and of course an XK is heavier than a WK.

As far as the diesel suggestion - we appreciate the feedback!

[jeep5253]

Originally Posted by JeepEngineers

We have actually pushed to have the antenna moved. (The toys I haul on the roof of my Commander interfere with my satellite radio reception too.) But so far, astetics have won out. If you don't mind, I'll forward your thoughts to those that control these decisions - as a customer you will have more influence than I do.

Hmmm.......Aesthetics or functionality ? I'll take the functionality, please. They could move it up front and paint it body color if they are worried about looks. Plenty of other vehicles have them up front. Yes, please forward to proper channels. Also, every Commander owner on the jeepcommander.com forum feels the same way.

[JeepEngineers]

Originally Posted by ahmed255

Could you please explain in more technical details the difference between the ESP modes operation “ESP partial OFF” and “ESP full OFF”

ESP partial off turns off engine management, but still uses the brakes during an ESP event. This means that the engine does not reduce torque.

ESP full off turns off engine management and brake management. This is the mode in 4 low and is selectable in 4 high at low speeds.

The brake limited differential part of traction control can not be turned off - it is used to provide torque to a slipping wheel when needed. This may not be considered part of the ESP portion of the system, but may be noticed.

Hope that helps.

[JeepEngineers]

Originally Posted by Unlimited04

my dad's commander has the 4.7L V8 and gets around 8 to 10 mpg. it is serviced regularly at the dealership. his previous WJ with the same engine got 25mpg on the highway. is the extra weight of the commander to blame here? what is Jeep doing to improve fuel economy in the commander, WK and all other vehicles? A suggestion - diesel with 30mpg available in all models.

The Commander is heavier and has more aero drag than the WJ, so your assessment is correct. There are many engineers working on fuel economy improvements for all of the Jeeps. Every avenue is being explored. We can't discuss future product, so we cannot share any changes that are coming. Every model year Commander has had some fuel economy improvement. We do offer the Grand Cherokee with a 3.0L diesel.

[ahmed255]

[QUOTE=JeepEngineers;5212138]

The brake limited differential part of traction control can not be turned off - it is used to provide torque to a slipping wheel when needed. This may not be considered part of the ESP portion of the system, but may be noticed.

QUOTE]

So what are the other parts or functions of the Traction control other than "The brake limited differential"?

[ds3806]

I'll second Jeep5253's comments. Once you use the racks the reception is gone.... kinda defeating the point especially on road trips when I like to listen to the sat. radio the most. Thanks again for your time.

[JeepEngineers]

Originally Posted by ahmed255

Is there any way to change the clock format from 24h to 12h in Commander 07?

Is your radio currently in 24hr format or 12 hr format?

[Unlimited04]

Astetics over-ruling functionality is a scary proposition for a Jeep. The Jeep has always symbolized to epitome of functionality. If you stray from the functionality history of the "Jeep" brand, then you defeat the entire purpose someone will buy one in the first place. Note: The most successful Jeep models ever produced have all put functionality first and astetics second. If we wanted a pretty car that didnt function worth a crap, we'd go to another company.

[ahmed255]

Originally Posted by JeepEngineers

Is your radio currently in 24hr format or 12 hr format?

24hr format

[ArloGuthroJeep]

Originally Posted by JeepEngineers

Weight and aerodynamics are definately a factor - the XK/WK are much heavier than a WJ, and of course an XK is heavier than a WK.

As far as the diesel suggestion - we appreciate the feedback!

1) How much does the XJ weight (aprox)?

2) What is the cause of all of the excess weight when (to my understanding) a unibody is supposed to be lighter then a frame/tub vehicle?

3) Are there realistic changes (assuming money is the driving factor) that could be implemented to save a worthwhile amount of weight (not asking for future, just asking whether weight could realistically be saved)?

4) Looking forward at future government regulations on safety & performance, do you forsee any significant barriers to the Jeep brand?

[JeepEngineers]

[QUOTE=ahmed255;5212149]

Originally Posted by JeepEngineers

The brake limited differential part of traction control can not be turned off - it is used to provide torque to a slipping wheel when needed. This may not be considered part of the ESP portion of the system, but may be noticed.

QUOTE]

So what are the other parts or functions of the Traction control other than "The brake limited differential"?

Traction control only has 2 parts.
1. Brake limited differential (BLD)
2. Engine management (torque reduction)

Essentially if BLD can restore traction that's all that is used. If that is not enough, then the power is reduced until traction is restored.

[ahmed255]

I noticed in Star Scan that there two thresholds for the Tire pressure gage sensor system, the first at 20 psi and the second was at (I think) 7 psi.

The alarm goes off at 20 psi, what happens when it reaches 7 psi (the lower threshold?

[JeepEngineers]

Originally Posted by ArloGuthroJeep

1) How much does the XJ weight (aprox)?

2) What is the cause of all of the excess weight when (to my understanding) a unibody is supposed to be lighter then a frame/tub vehicle?

3) Are there realistic changes (assuming money is the driving factor) that could be implemented to save a worthwhile amount of weight (not asking for future, just asking whether weight could realistically be saved)?

4) Looking forward at future government regulations on safety & performance, do you forsee any significant barriers to the Jeep brand?

1) Base curb weight for XK 4x2 automatic is 4649 lbs - this will go up a max of 5239 for a 4x4 Overland.

2) A lot of the reason is safety equipment (airbags for example) and all the creature comforts that are expected in a modern vehicle.

3) Exotic/expensive materials such as carbon fiber or magnesium are certainly an option, but of course as you said, cost is a factor.

4) There are significant barriers to achieve the 35 MPG government mandate. On the other side, FMVSS 214 has been updated and will require improved performance in side pole impacts in the future. This requires additional reinforcements which add weight. Still the problem is solvable. We are very aggressively reviewing all fuel economy improvement opportunities.

[ArloGuthroJeep]

Originally Posted by JeepEngineers

3) Exotic/expensive materials such as carbon fiber or magnesium are certainly an option, but of course as you said, cost is a factor.

Carbon fiber is very difficult to weld to and every time I weld to magnesium it bursts into flame

[JeepEngineers]

Originally Posted by ahmed255

24hr format

What kind of radio do you have?