Wow, at 90 mph that is spectacular, but I guess in hot weather you get the offset of lower air drag. I have averaged 330 Wh/mi over the life (so far) of my 2015 P85D and Tesla tell me that I "pay" for the P with some reduction in efficiency. At 90 mph (totally illegal here) I would be looking over 400 I think.
90mph is the max speed for TACC/Autopilot, and while you think that's what you're driving for a sustained period, with traffic, getting on/off interstates to get to chargers, that's not an overall average for a day. Nonetheless 322 Wh/mi for that trip in S90D is excellent. My lifetime Wh/mi in my S90D was 342.
On the recent crosscountry trip, compare to my Raven lifetime 308 Wh/mi:
May 30: Las Vegas to Eagle CO 653 miles. TACC to Beaver was set at 80mph, and after that to 85 or 90. Calculated distance/time speed while driving was 79mph, which shows the discrepancy between TACC settings and what actually happens. That leg had a net elevation gain of 4,000 feet and consumption was 330 Wh/mi.
June 4: Eagle, CO to Wichita, KS 654 miles. TACC was 5mph over speed limit in Colorado and 85mph in Kansas. Calculated distance/time speed while driving was 74mph. Consumption was 291 Wh/mi, favorable due to net elevation loss of 5,000 feet.
June 6: Wichita, KS to Osage Beach, MO 290 miles. This was all on the secondary route Hwy 54 and I needed to limit TACC to the 65mph speed limit in order to make it with no chargers on that route. Consumption was 288 Wh/mi.
June 8: Osage Beach, MO to Auburn, AL 740 miles. The first leg was 260 miles to Miner, MO, about half on secondary roads. TACC on the interstates was 75 or 80 but there was some heavy rain and also about 20 minutes of slow driving in and out of Birmingham. Calculated distance/time speed while driving was 68mph and consumption was 331 Wh/mi. Notice this is the same consumption as the Nevada to Colorado day averaging 11mph faster. The reason for the earlier day being more efficient is not hot weather (overall temperatures were not that different) but that the earlier day was in thinner air averaging around 6,000 feet.
June 9: Auburn, AL to Belleaire Bluffs, FL, 484 miles. The first leg was 180 miles of mostly secondary roads, the rest TACC on the interstates at 75 or 80, with some short bursts of heavy rain. Calculated distance/time speed while driving was 65mph and consumption was 318 Wh/mi.
Bodyhauler's trip was over 4,000 feet in all of New Mexico and part of Arizona, so had a similar assist in efficiency due to altitude. While in Colorado I took a 204 mile daytrip to Independence Pass at 12,000 feet. That averaged 250 Wh/mi, which was assisted by slower speed on mountain roads as well as the altitude.
One other note: My S90D had similar consumption at home as on road trips. The drivetrain efficiency improvements to the Raven are especially helpful in city driving. Consumption was 297 Wh/mi during the first 3 months of the Raven before taking any long trips.