This is only true on the Model 3. Indeed, on the S, the dual-motor variants were more efficient due to different gearing. It is still unclear the community why

This is only true on the Model 3. Indeed, on the S, the dual-motor variants were more efficient due to different gearing. It is still unclear the community why the 3 dual motor variants are as much as 10% less efficient. It is not totally accounted for by weight, and the extra induction motor should be capable of torque sleep.