Well, let's see.

We think we know that the car has ~10% less range on the same battery (Sig XP90D @240 EPA vs SP90D @ 253 EPA "+6%" per Tesla.)

We think we know that the car is 1200 pounds heavier (a tech gave the weight as 6100 pounds to someone on the forum (Post#543

here,) and that's consistent with the promised 0-60 times vs the model S 0-60 times.)

We think we know that the X is 198" long, 66.3" high, and 89.4" wide with 7.2" ground clearance vs the S's 196" length, 56.5" height, 86.2" width, and 5.6" ground clearance. The S is 77.3" with the mirrors folded. (Post#447

here:)

We assume the same powertrain efficiency and the same tire/drivetrain rolling resistance per pound.

With a 24% heavier car, the rolling resistance should be 24% higher - but rolling resistance is typically a small factor at freeway speeds compared to aerodynamics.

The X is (66.3-7.2) 59" tall vs the S's (56.5-5.6) 50.9" - 16%% more cross sectional area. Assuming the same mirrors, it's also 3.2" wider = 4% more cross sectional area.

If rolling resistance had no effect, the Cd has to be ~9% lower to get the demonstrated range with ~20% more frontal area. If rolling resistance is 50% of the freeway number, Cd has to be at least 20% lower to get the range shown - because the losses from rolling resistance exceed the demonstrated range loss, and the car has to have a lower overall CdA.

The reality is presumably somewhere in between these two cases assuming our baseline "facts" are correct.

Walter