Agreed, which is why I push mine harder than yours with Ludicrous launches from pretty much every stop. But overall, that won't really drive up wh / mile usage overall. Another factor to consider is how steady your throttle foot is. My wife tends to do badly compared to me in the because she's not steady on the throttle even when she's attempting to go a constant speed. She'll vary around a lot in a 5 mph range accelerating slightly and decelerating slightly in a constant cycle that ends up resulting in tons of regen when she's attempting a steady freeway speed vs me where I don't use regen unless I have to. For instance, if I want to slow down from 70 to 60 because of conditions, I coast down to the speed without regen when possible. Sure regen is better than physical breaks but it's not as good as if you never had to take it out of the battery in the first place.
Dr Lucas, I may have identified the steps needed to explain the missing range in Tesla batteries.
Please look at TMC, Model S Forum, Battery & and Charging, sub-thread entitled “Calculate usable battery capacity based on rated miles values”. I followed your approach to test whether my 253 mile Rated Range was illusory. My experience is summarized in the 12th part of the thread. I first found that my 253 had dropped to 252, but then I could not get more than 231 actual miles at the Rated Rate of 310 Wh/mi. In other words, my initial results matched yours.
Thereafter, based on comments I received, I made a number of adjustments that are explained in the posts. The bottom line was that I was able to confirm 252 miles Rated Range. Please see if the method makes sense to you.
The main adjustment was to ignore the car’s metered kWh usage and measure the amount actually loaded into the battery at the end of the test, which I could see using my Remote S app. The second is a rough guess as to how much time the battery was being drained while idling in traffic, etc.
(What is not resolved is Tesla’s overstatement of the available capacity of certain of its batteries. For example, the 85 kWh battery has 77.5 kWh usable, no more. All of this is discussed in other parts of the thread.)