I’ve owned the Defender for about a month. When I reach a red light and release the accelerator, the car slows down, but I feel like it sometimes light jerks a few times before coming to a complete stop. It’s like a person running, feeling tired and breathing unevenly. I experience something similar when I accelerate; the car seems to speed up very abruptly instead of gradually. Is this normal when I’m using the comfort mode, or is there something wrong?

 

Assuming you're under warranty, take it to the dealer and have a technician or service advisor ride with you so you can show them the problem. It sounds to me like the transmission will need to be recalibrated.

 

The sensation you describe while decelerating to a stop just sounds like the transmission is shifting down a few times, as it normally does. With each shift, there's a small change in engine braking that you can feel. You can feel that even when braking lightly. Brake heavily and the braking will mask the shifts. If that's what you are feeling, then this is normal.

The abrupt acceleration is probably just the boost kicking in. Also normal.

It doesn't sound like there's anything wrong to me.

 

I feel like the start/stop causes the car to jerk when slowing down, actually stopping the engine before stopping the car. The first thing I do after starting the car is turn it off.

 

Yes. I also feel this issue when lightly brake. Your car is same?

 

Yes, it's normal and my car does the same.

But the engine start-stop should absolutely not turn off the engine if the car is moving even a little. Only at a complete stop.

 

Auto stop/start on the MHEV can shut off the engine at 2-3mph and use the 48v system the rest of the way. This is how most MHEV systems work and it is a lot more unintrusive and seamless than auto stop/start on conventional ICE vehicles. Some vehicles with larger MHEV batteries, mainly Audi and Mercedes products allow the auto stop/start to activate as high as 5-6 mph, use the system to provide torque fill to eliminate turbo lag, and allow the engine to turn off when coasting at high speeds.

Audi introduced a new MHEV plus technology that allows for full electric driving at low speeds (i.e. in stop & go traffic or slow city driving) and provides more boost to the ICE engine. This is debuting on the new A5 and Q5, but will not be available in the US, as our emissions regulations are lax compared to the EU. It is very interesting and impressive tech and worth reading the press release about it: https://www.audi-mediacenter.com/en/...-at-audi-16470