It is a transmission issue but nothing to do with gas vs diesel (unless they are using two different transmissions). I had an FPace for 40k+ miles and no hesitation at all. It is a Discovery thing.

 

 

Had a similar issue with a 2010 Escalade, had a 400HP 6.2L V8 with the (then) new 6 spd auto. At certain speeds when hitting the gas it had a lag where the ECU and transmission was trying to decide on a gear while cutting power to the engine. Definitely not an engine issue as those engines have a ton of power at any RPM, but rather a transmission and engine ECU programming issue. I would think they will program the Si6 very different from the TD6 on shift behavior to adapt for the different engine power profiles.

Waiting on my 2019, and hoping the issue is better or resolved by then (or at least have an update to fix it). Sounds like a pain.

 

That is why I want to reset my ECU. I think I broke it in per instructions and somewhat softly. Having driven it harder lately - it seems that some lag has gone away.

 

I was trying to make a point on the downshifting algorithm.
Two cases for comparison purposes:
Si6: --> gas paddle pushed down hard --> ECU first think to down shift to 6, then hesitating about why not shift to 5 instead --> delay in the thinking/ramping RPM process
TD6: cruising RPM 1800 @ 7th gear --> ECU knows max RPM is 4-5K --> ok, shift to 6th and that is all I can give

On the other side, this TD6 seems to ramp up in RPM fairly quickly, unlike typical diesel engines...

On the side, the paddle shifter can be set to work in both D and S mode, this is proven to be effective to avoid unwanted tranny hesitation.

 

My t/m hesitation is only 1st to 2nd and 2nd to 1st. Perfect shifts in other gears.

 

That is good info. Perhaps more spirited driving from new will be a good thing, the instructions just state not to floor it or high rpm while cold

 

The major hesitation I get (and it is not every single time) is in first or second gears. I originally thought that the issue was a 2nd gear start, but even shifting into Sport mode (which should mean 1st gear start) it will still bog.

There doesn't seem to be any rhyme or reason to it. Standing start, creeping start, seems to happen, or not happen, during all.

 

How long have you guys been in the vehicles? I had this happen to me for the first 500 or so miles after I bought used ~10k miles, then it stopped. I am not sure if my driving style has changed or if it "learned" how I drive, but the gear 1-2 or 2-3 shift that seems to lurch, no longer does this. I have put on about 2k miles.

 

I've been in this D5 Si6 for almost two months and have put about 3,500mi on it.