Is low regen setting best for highway cruising?

[scottm]

Sorry to hear that. My brake pads and discs will probably last the life of the car without change.

 

[Silent Ludicrosy]

..make it simpler to demonstrate laws of physics (conservation of energy) and imperfect energy conversion of modern day electrical systems.

Flat ground. Any speed, but 60 mph is good. Get in any Tesla and drive it.

Sample 1: standard regen.
At point X lift foot off pedal completely.
Begin computing battery charge power. (hard to do but say you could measure this precisely)
Car comes to rest at point Y.
Using only the power returned to battery from this decel cycle, resume driving in any fashion you choose under the car's own power, until that charge amount is depleted. Let's assume (best case) once the energy is depleted, allow the car to roll out rather than halting abruptly.
Car comes to rest at point Z.

Sample 2: zero regen.
Re-do the run arriving at point X at exactly the same speed as first sample. Car can be at any charge level at the beginning of the run.
Flick the car to neutral. No charge is returned to battery.
Car rolls past point Z. Every time.

Repeat at any speed.

Repeat at low regen setting instead of standard.

Sample 2 always surpasses point Z.

Level deceleration is not the same problem as downhill constant speed/ acceleration. But I made a spreadsheet to see what would happen anyway.

Scenario 1: Start at 60 mph and use regen to slow at a rate of 1m/s^2 (about .1 g) until 30mph, then use the regen energy to hold 30mph until the regen energy stored in the battery is gone, then roll out to 0 mph.

Result:
2762m with no headwind
2394m with a 10mph headwind

Scenario 2: Start at 60mph and use no regen, just friction and aerodynamic drag to slow to 0.

Result:
2469m with no headwind
2112m with 10mph headwind.

Assumptions:
Car weight 2250kg (P100D)
Air Density 1.225 kg/m^3
Drag Coefficient .24
Rolling resistance coefficient .01
Frontal Area 2.34m^2
Regen efficiency 90%
Motor efficiency 90%