Awesome range when practicing energy management -- range is as advertised or better in my Cybertruck

[Cybergirl]

My thoughts on possibly coming out ahead by not converting regen power and gaining speed, is that whatever you might gain by this, you're losing by having to increase your speed, and thus increasing wind resistance.

Apparently not judging by the OP's experience.

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[DRKTruck]

Yeah this makes sense. Regen will only help if you wanted to slow down anyway, especially when coming to a full stop.

Can you turn off regen completely with auto pilot and FSD? The computer would not be able to figure out when to not use regen vs using it (not wanting to slow down vs slowing down).

My experience with BMW i3 was the same way. Using regen is akin to driving with your brakes on.

 

[Willspence]

“… and the peddle..."

So sorry your dad couldn’t spell “pedal”.🥹

 

[GhostAndSkater]

I was thinking about the neutral thing but don’t want to get confused and accidentally put it in park

Afaik I know it won't go into park if you are moving unless you hold park for a few seconds, which would engage parking brake in a emergency if you lose your brakes

 

[beastew]

Nice! So glad you posted this. I was starting to worry and my family was just adding in to it by telling me what he read. Can’t wait to get mine & see what I get.

 

[dandor]

Once you learn how to drive a Tesla, your efficiency will get better. You don't have to do anything special. Use Regen to stop and don't use brakes, this takes some time and you perfect it after awhile. Just drive at a constant speed and avoid accelerating like a maniac. Not only will you save money with better efficiency, but your tires will last longer.

I won't baby my truck and from the first 400 plus miles, it looks like 360 to 380 Wh/mi for highway driving will be the number for me. I also will get up to 75 to 80 mph for stretches.

 

[HaulingAss]

My thoughts on possibly coming out ahead by not converting regen power and gaining speed, is that whatever you might gain by this, you're losing by having to increase your speed, and thus increasing wind resistance.

There is some truth to this, it really depends upon the exact scenario, amount of cargo weight, steepness and length of the grade, etc. Imagine a grade that is uniform in steepness and endless and has a terminal velocity in your vehicle of 65 mph. That is, the vehicle will never exceed 65 mph due to increasing aero drag at higher speeds. You will be net energy ahead if, instead of coasting down the hill at 65 mph, you regen down it at 50 mph.

If hypermiling for maximum efficiency (which I do ocassionally for fun) the real trick is to anticipate traffic and grades so you don't need to use regen or pick up excessive speed. For example, if I know after the crest of the hill, there is a long downslope, I can gradually reduce speed up the hill, so I crest it at a very low speed, then I can coast down the otherside, picking up speed. I will generally start to feather in some regen as I approach a speed high enough that aero drag becomes big enough to matter.

To be clear, this can only work on low traffic roads, I would never inconvenience other motorists. But it can be an enjoyable way to pass the trip on rural roads if not in a hurry and just enjoying cruising through the scenery. It's like a video game, only more real.

In general driving in normal traffic, when wanting peak efficiency without inconveniencing other motorists, the most important tip is to never accelerate to a speed that will shortly require you to regen. Try to smooth out the flow of traffic so it flows more predictably.

While regen increases the efficiency of city driving by around 20-40% (depending upon particulars and driving style) it can actually reduce efficiency on the highway if you are not an aware driver and you find yourself using regen to avoid hitting the car in front of you. Humans are terrible drivers (even though most of them think they are better than average). People, in general, do not drive for practicality, they use their vehicles in an emotional manner, perhaps to get their frustrations out, or to try to exert dominance over others. Sometimes it's just a general lack of awareness. This is evident in freeway traffic with the "yo-yo" effect, cars speeding up and down for no apparent reason. Using a larger following distance can increase your efficiency and smooth out the traffic flow behind you. Sure, people will cut in front of you when the gap is bigger, but so what?

Some people are so set in their ways they have difficulty learning a simple thing like one-pedal-driving. They are so accustomed to using the gutless throttle on their ICE car as an on-off switch, they can't seem to grasp the idea that is not a switch, but an infinitely adjustable acceleration control. And that "acceleration" encompasses "deceleration". Science speaks of deceleration as negative acceleration, there is no deceleration. These people can't break the habit of fully lifting their foot off the throttle everytime they want to coast or slow down a little. It's like they were programmed one time and then their brains became fossilized. They are so rigid in their ways, they don't ever want to learn anything new.

In any case, while regen braking can increase overall efficiency substantially, it's almost always more efficient to drive in a manner that requires as little regen as practical in any situation. The underlying reason for that is regen breaking requires a round trip of energy from the drive motors to the batteries and then back out of the batteries to replace the lost momentum. Each way you lose at least 10% and there are other losses involved such as those consumed by rubber hysteresis and gear friction when changing velocity. I think regen braking is only about 60% efficient when you include the round-trip acceleration needed to regain your previous momentum. It's always more efficient to maintain your momentum, when possible (with the exception of at higher speeds due to the rising cost of aero drag as the speed of the vehicle increases).

 

[GuyV]

I've not received my CT yet but my question is, in a long downhill, why would I choose to not regen

I like your post but my question is, when going on a long downhill, why would I remove the regen? I thought that's the chance to recoup some energy lost.
Thanks.

Momentum is even more efficient than regen, no conversion loss in storing and reusing it.

 

[GuyV]

On a downhill hill you ideally want to not see any of the grey bar nor green bar, that’s coasting which will maximize efficiency. It takes a very precise foot to do it but it’s a fun challenge. Not Sure why the software won’t just do this automatically as in our GLE450. The GLE450 is a mild hybrid and when driven in Economy mode the engine cuts out on a downhill and it will coast. If you tape the brakes Regen kicks in. It’s automatic, in the CT it requires skill to accomplish this manually.

I've always wondered why Tesla hasn't bothered to provide and Eco Mode. I just guessed that they didn't want hypermiling as part of their image of sporty power, speed and innate efficiency.

 

[chinokie]

Momentum is even more efficient than regen, no conversion loss in storing and reusing it.

Sorry but it is not. Using regen captures energy and stores it in the battery. It also slows you down which means you are wasting less energy in drag.

Regen is the correct answer. Anybody thinking momentum or speed is lossless is incorrect. Google Drag vs Speed and you will see the difference.

 

[CyberGus]

Using regen is akin to driving with your brakes on.

No amount of braking will ever put a drop of gas back in your tank.

 

[Cyberostachu]

Momentum is even more efficient than regen, no conversion loss in storing and reusing it.

Thanks. I'll try that.

 

[HaulingAss]

Sorry but it is not. Using regen captures energy and stores it in the battery. It also slows you down which means you are wasting less energy in drag.

Regen is the correct answer. Anybody thinking momentum or speed is lossless is incorrect. Google Drag vs Speed and you will see the difference.

Momentum itself is lossless, it's the running into all those air particles that slows you down. So, yes, slower is more efficient, all else being equal. But not all else is equal.

Almost certainly, while keeping it under 50 mph it is more efficient to coast than to regen and then accelerate back. At higher speeds it becomes more of a wash. Under around 50 mph (or maybe even 60 mph), the aero drag is smaller than regen inefficiencies. It would depend upon the specific vehicle.

 

[Cyberostachu]

Momentum itself is lossless, it's the running into all those air particles that slows you down. So, yes, slower is more efficient, all else being equal. But not all else is equal.

Almost certainly, while keeping it under 50 mph it is more efficient to coast than to regen and then accelerate back. At higher speeds it becomes more of a wash. Under around 50 mph (or maybe even 60 mph), the aero drag is smaller than regen inefficiencies. It would depend upon the specific vehicle.

Cool. Thx.

 

[DRKTruck]

No amount of braking will ever put a drop of gas back in your tank.

Thats an off topic comment.

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