There's two factors that lead to increased consumption from the larger, performance wheels. One, the increased weight leads to increased rotational mass. You can look into this on your own, but it's quite well proven that this requires additional energy to spin. Not all of that energy is recovered during regeneration thus overall consumption is higher. Second, these wheels are designed to increase airflow to the braking system for cooling purposes. The energy to cool the brakes is not free. There's an old saying, your mileage may vary, and it's certainly true with Teslas. How you drive is the biggest factor, but certainly the weight of the wheels can not be ignored.
I posted a photo showing the 19s and 21s with tires years ago on the scale. The 21's were maybe 1/2 lb more than the 19s. Like I said, there's no difference in mileage between the two sets on my car.
I got a P85 Sep 2020 with 94K miles, 19" tires, Atlanta and averaged 248 Wh/mi until the weather turned colder. Since November or so my average is 264 Wh/mi (Jan 2021 at 106K). I will leave B as lifetime (just since Sep) and begin resetting A each month. For now, all numbers are cumulative. Incidentally, I generally drive at or BELOW the speed limit with limited HVAC. Demos are largely over with. The tremendous acceleration is not a big feature for me (previous car was a Prius).
This is interesting, considering 19” OEM Goodyear Eagle Touring tires weigh 26 lbs versus the 21” staggered OEM Contis that are 28 lbs up front and 31 lbs in the rear. For the overall weight to be only half a pound difference means the larger 21” wheels will have to be considerably lighter material...and still somehow account for staggered vs squared. I just know my Wh/m immediately dropped 12.5% after downgrading from 21” to 19” stock wheels. Went from 302 Wh/m to 264Wh/m the moment I switched tires, same commute, same weather conditions, same driving behavior. The 21s obviously look better but I’m sticking with the 19s for range and lower tire costs.
I am very impressed with all the consumption I read on here... With my 2019 Oct Raven Performance Model S I have a 378 lifetime average. Mixture of motorway (75mph) and short local trips. I don't drive without aircon or heated seats etc because what is the point. That makes my full range 264 miles, quite a lot short of the claimed 347. I am thinking about changing it for a Taycan Turbo because the the build quality / reliability of the S is so bad, but if the Taycan has the same relationship between claimed range and actual range as my Tesla then the Taycan's 260-odd claimed quickly becomes under 200, which is not really enough. But I still get free fuel from Tesla so cannot complain really, it just means more stopping.
@2madcal you might want to see if Tesla can do an over the air check on your car. My car matches yours - October 2019 build, Performance. I have 19" wheels versus maybe 21's on yours? Our driving habits seem identical. Either on the highway averaging 75 mph or in town running errands. No rush hour stop and go driving. Heat and A/C always used when appropriate. My November 2020 one year average was 287 Wh/m and I'm not all that hesitant to enjoy the torque. This winter has involved zero longer trips and despite the short trip and cold weather penalty on efficiency the average has only risen to 289 Wh/m. Your numbers seem really high for what you describe as pretty sane driving.