Jason Hughes released this month his second video from efficiency tests of Tesla P85D and P85.

In the first one, the P85D with firmware v6.0 2.0.81 was ~16% less efficient than the P85.

Now. with firmware v6.1 2.2.140, it seems that the efficiency results between the two cars are similar. The reason is sleep mode for one of the motors at lower loads.

"Final results!

P85: 111.3 miles, 35.0 kWh, 315 Wh/mi P85D: 112.3 miles, 35.4 kWh, 316 Wh/mi

For comparison, the results of the previous test (pre-torque sleep) were: P85: 111.3 miles, 34.1 kWh, 306 Wh/mi

P85D: 112.2 miles, 39.5 kWh, 352 Wh/mi"

"Leg 1 of my second efficiency test of my new P85D (firmware v6.1 2.2.140) and a P85 on the same route, at the same time, at roughly the same speeds.

The previous test on older firmware can be found here: https://www.youtube.com/watch?v=Ndxjt2f2Tf8

Detailed information on this run can be found here: http://www.teslamotorsclub.com/showthread.php/42134-P85D-vs-P85-Efficiency-Testing-Take-2?p=897458&viewfull=1#post897458

Sorry for the shaking of the dash videos. The GoPro mount bounced/vibrated a bit on the trip. The dash videos are also perspective corrected so the dash looks straight on (the GoPros were mounted to the left side of the dash looking at it on an angle)

This was immediately after Tesla pushed the first "torque sleep" update to the P85D. The P85 and P85D are nearly identical in energy usage now."