[CalTom]

Here is the presentation video of this weeks unveiling of the 500X at the Paris Auto Show. It is a video of the powertrain, If I'm not mistaken, this is the same as the Renegade:

 

[BeepBeep]

Does the Renegade also come with the rear drive decouple in 4x4 for higher Hwy mpg?

 

[CalTom]

Does the Renegade also come with the rear drive decouple in 4x4 for higher Hwy mpg?

Yes, that is correct, from the jeep.com Renegade brochure:

"Class-Exclusive Rear-axle Disconnect Standard on 4x4 Models"

 

[tony]

good to see it does, but what sort of difference in MPG could this make? is it significant or minimal?

 

[raz-0]

good to see it does, but what sort of difference in MPG could this make? is it significant or minimal?

decoupling the spinning bits with mass? IIRC about 10% is a reasonably middle of the road estimate. It really depends on various ratios, mass of the bits, the rolling resistance of the tires, and how much of the mass the rear tires are spinning in a purely parasitic setup.

That's if you are comparing traditional AWD vs something that decouples. If you are talking "let the computer sort it out" vs. "I pressed the just leave it unlocked button", probably pretty small to negligible.

As a point of reference, back when people were trying to figure out how to make 1G and 2G eclipses and talons go fast, pulling all the driveline from the transfer case back resulted in about 25% higher dyno numbers. Of course with that you weren't dragging the rear wheels, taking losses from bearing friction and tire deformation, etc. Manufacturer claimed differences between FWD and AWD were 20%, reality was less than that, and you weren't taking into account the drag from gears in the transfer case, rear differential, and cost of spinning the prop shaft. Some of the geekier engineering geeks tried to come up with an answer, and that boiled down to less than 20% but more than 5%, which was pretty much a "well duh, we knew that" conclusion.

 

[tony]

Seems like all we can do is just guess it

 

[Rivmage]

Why not just look at a FWD vs AWD mpg to see the gains, I know the AWD system weights more so will impact the results some but, should give a good idea what the MPGs will be with the rear disconnect.

Scott

 

[raz-0]

Why not just look at a FWD vs AWD mpg to see the gains, I know the AWD system weights more so will impact the results some but, should give a good idea what the MPGs will be with the rear disconnect.

Scott

We could. but nobody has actual MPG numbers for the us engine options. So....

 

[Rivmage]

We could. but nobody has actual MPG numbers for the us engine options. So....

I know...I meant once they are released.

Scott