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Yes, there some places and times where a Tesla might be worth the money; maybe

6451 Views 64 Replies 21 Participants Last post by shrox, Dec 17, 2021

Packard V8

Discussion Starter · Nov 27, 2021

Some family members have a place in Moab, UT and we love to send time there with them hiking and visiting the six state and four national parks. Seeing is not believing; just beyond human comprehensionl

The roads through the parks are always crowded, 30 - 45 MPH speed limits, curves, hills and spectacular scenery on both sides and sometimes straight up and straight down.

They have a Tesla with autopilot and follow cruise; these two features our Bolt lacks makes the day in the park in a Tesla a walk in the park. Thanksgiving weekend is crowded and there was a twenty-minute-stop-and-go line just to get into the park; follow cruise made that cake. Then, set the autopilot at 45 MPH and the Tesla does the rest. If the car in front doesn't hold a steady speed, the autopilot can be set to maintain 1 - 5 car lengths behind the car in front and follow the road. A gentle hand resting on the bottom of the steering wheel is all that is necessary and the driver can enjoy the scenery as much as the passengers. Tesla knows when the speed limits change and will slow and go as necessary.

Having said how much I love autopilot in that situation, there are times it gets it wrong and will scare the shite out of everyone in the car. A cyclist on the shoulder will cause autopilot to panic, slowing rapidly, beeping warnings and switching off. Coming down the mountain toward the park entrance, there are a series of 15 - 25 MPH 180-degree switchbacks. The autopilot had been slowing for most of these, but the last one it ran straight into it at 45 MPH, not noticeably slowing. The Tesla's owner says, "Trust the technology." but there was a vertical sandstone bluff staring us in the face; trust, but verify.

Bottom line, the Tesla autopilot is almost as smooth as a really good driver; but it's not yet anywhere near autonomous, but in the situations for which it is suited, it's magic.

jack vines

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atc98092

· #4 · Nov 28, 2021

Willie said:
My '22 Bolt EV with adaptive cruise control has a following distance feature, but not the main-highway SuperCruise that's available on the EUV. I guess neither of those would be of use in your situation, right?

Most likely that is not a super-cruise mapped highway.

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atc98092

· #14 · Nov 28, 2021

@EVmunkey sounds like we are a similar age. I prefer using adaptive cruise control on the open freeway, as it relieves me of any concern for monitoring my speed, and keeps me from a possible ticket. Around town, I use it when I'm within a city that has a reputation for ticketing at the drop of a hat for even a few over. But in town I use standard cruise, as the adaptive version is often too sensitive about surrounding traffic. And with the Bolt, I never use cruise when I'm in hilly areas, as it does a terrible job of generating regen while in cruise. It will not go beyond coasting regen, instead applying the brakes to control speed. I've documented it quite clearly, and I'd rather gain back that wasted energy, not waste it as heat with the brakes.

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atc98092

· #19 · Nov 29, 2021

Fivedoor said:
Interesting. My 2017 Bolt never uses the friction brakes when the cruise is on, even on steep mountain roads. The regen gets fairly high on a steep decent, but it has never "pegged out" at 70 KW.

Keith

Others have reported the same, but there’s no question my EUV is using the mechanical brakes going down hills. I’ve tested both with and without cruise enabled, both with and without one pedal turned on. Regen maxes out at 10kW on cruise, while it goes much higher without cruise. There’s no other explanation for the difference.

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atc98092

· #38 · Nov 30, 2021

NortonCommando said:
That is strange behavior.
How are you certain the friction brakes are slowing down the car? Did you point an IR temp reader at the discs?

I came down Pikes Peak in my Volt years ago like the dumb tourist in front of me. I could smell the hot brakes.
We both just used the brake pedal in D, (I assume).
At the Park Ranger safety stop they read your brake temps.
She was told to "park over there and let your brakes cool off".
Mine were 69° on a 65° day. I asked him to measure front and rear.

My certainty comes from the car speed being controlled going downhill, with the lack of regen higher than 10 kW. I could also feel the speed being controlled, and it was a bit rough, as if it was applying and releasing the brakes. Going down the same hill, but using regen to control the speed (one pedal more or using the brake pedal) I saw significantly higher levels of regen, and I could hold the speed smoothly. Really noticeable from the driver’s seat

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atc98092

· #40 · Nov 30, 2021

Packard V8 said:
Dan, you see and feel what you saw and felt, but in four-and-a-half-years of Bolt ownership in hilly/mountainous country, ours just doesn't behave that way.

When we first got ours and were charged to 100%, starting out down a steep hill, there was no regen; since that experience, we've always used Hilltop Reserve and whether on cruise control or manually in L or L+paddle, maintaining the cruising speed feels the same and I've never felt the "bit rough" you describe.

jack vines

All I can figure is they changed something for 2022. Before my Bolt i drove a PHEV, and I understand regen limitations with a full battery. That isn’t the case for me, as I don’t charge over 90%, and my testing is coming after some additional driving. It’s certainly strange, but I’m certain of my conclusion.

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atc98092

· #42 · Dec 1, 2021

Sean Nelson said:
I doubt very much that the Bolt EUV uses the hydraulic brakes any more than the Bolt does (which is basically never), considering that it's using the same drivetrain and control electronics.

The reason Regen maxes out at 10kW on cruise is likely because the car never has to slow down by more than around 1km/h and therefore doesn't need to absorb very much energy to do so. When you turn off cruise and use the pedal it's super easy to exceed that simply by slowing down more.

Try going down the hill in cruise and hitting the "Set -" button rapidly so that your speed decreases quickly, that'll require the car to regen more energy in order to slow down.

Nope, I turn cruise off on the same hill and I see double the amount of regen. It’s using the brakes.

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atc98092

· #44 · Dec 1, 2021

Sean Nelson said:
I'm sorry, but that's something I just can't believe unless I see it myself.

Not my problem if you don’t want to believe it. I’m simply stating the facts as the car shows.

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atc98092

· #52 · Dec 13, 2021

Actually, Autopilot isn't really a problem name. The problem is people misunderstand the word. In aircraft, the autopilot is very similar to what Tesla does with theirs. It's not a complete flying solution. It only does what it's programmed to do. The more sophisticated systems can control the aircraft practically from takeoff to landing, but it's not an autonomous system. But people seem to think that word stands for a system that can do "everything".

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atc98092

· #54 · Dec 13, 2021

Sean Nelson said:
And what do you think the phrase "Full Self Driving" might mean to the public?

I have a great deal of trouble with that name. Even if it did 100% what they say it is going to, it's still not "full" self driving.

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atc98092

· #56 · Dec 13, 2021

OK, stop with the political comments now, or expect a ban. This is an auto forum, not politics.

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atc98092

· #60 · Dec 13, 2021

Autopilot in aviation can be used for everything other than the actual takeoff roll and landing flare. And there's a small number of aircraft/airports certified for actual auto-land. Yes, the airport has to be certified as well as the aircraft and flight crew. But autopilot is used for climb, cruise, descent and approach, so much more than just cruising at altitude. Available time for a response can differ greatly.

But what aviation autopilot does not do is look for other traffic and alter the aircraft course to avoid. That requires pilot awareness and action. Technology like TCAS provides the pilot with another pair of "eyes" looking ahead, but the pilot must still take the appropriate action. And TCAS can have false positives as well. I work in aviation ATC quality control, and we often have a TCAS event that receives a warning on properly separated aircraft.

So, any sort of autonomous operation in an automobile is going to be vastly more complicated than the "simple" autopilot used in aviation. I agree that the margin for error/time available to determine an action is far shorter for a vehicle based operation. Potential situations can arise as quickly as someone stepping off the curb with the car approaching. Something like that can't happen in the sky.

Tesla's Autopilot is much more similar to what is used in aviation than what is required for "self-driving".

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atc98092

· #62 · Dec 13, 2021

In aviation, it's been labeled autopilot for many decades. I've been a controller since '85, but the first rudimentary aircraft autopilots were created in 1912. I think the PLH is tied to some pre-autopilot functions, things like basic heading and altitude holding. I did a web search but found nothing. Checking Wikipedia, I found these details. The Sperry Corporation had a very basic system way back in 1912, just a heading and attitude holding system. Bill Lear (of Lear Jet fame, among many other things) was awarded the Collier Trophy in 1949 for his system which included the ability to fly an approach.

I do agree that that way Tesla markets their products is over the top, perhaps approaching the limits of legality. But that's for the NHTSA to determine, as they have the legal power to enforce something like that (I think). For everything Musk has done that is good and makes sense, this is one area that he's wrong, and simply won't back down.

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