Can someone please explain to me what it is and if this is an important option not to miss?

 

https://landroverforums.com/forum/20...please-108788/

Discussed in the old thread linked above.

I'd recommended the upgraded audio system with the active rear diff. To cover up the clunking sounds at low speeds.

 

I think it's a rare owner that would actually need it but to each his own. There was a YT video somewhere that had one with and one without for comparison. The one without was very capable and well beyond doing whatever I would be doing with it. If you're buying it first and foremost to offroad then in that case yes I'd say go for it, add it on. Otherwise my JLR dealer said it best with a chuckle, virtually nobody actually takes these things offroad. It's the look. For snow driving if that's your primary it's exceptional without the extra diff, I can vouch for that.

 

I don't have active diff.
Drove thru the snow yesterday( on winter tires and no specific drive program selected), runs like on tracks, while accelerating in turns - almost no drift or anything, good traction, good braking.

 

We have it along with the torque vectoring. The only time I’m aware that the computer used it was off-road in CO. Steep downhill off-angle into a hard switchback covered with melting wet snow and mud. Geared low, maybe 2mph, both feet on the floor. I could hear and feel the brakes locking independently to keep from sliding. Insanely smart.

 

I “wanted” the rear locker, but when I found a near perfect specced Def that didn’t have it, I got real with myself. I’m driving my def on the freeway back and forth to work. I’m not rock crawling in the mountains and never will. Camping is mostly fire roads where the raised height and center diff are more than sufficient to get me to where I’m going.

I think it’s a “Lifestyle” choice that 97% of Defender owners wont ever use. I’m not taking my 90k defender off road anywhere that the rear locker would make a difference. Better to buy a 2012 FJ cruiser for that.