AP/TACC Should I or Shouldn't I?

AP/TACC Should I or Shouldn't I?

2018 LR RWD, 17K miles

The clock is ticking on the deadline and I'm on the fence whether to spend $2K for this upgrade. For those who have AP/TACC (please no FSD inputs), can you please provide me some simple "Pros" and "Cons" to having it? I don't drive long distances very often (working part time now) but do live in a big city so I do drive most of my miles on the highways/loops to get to other parts of the city. Thanks!

h2ev | June 26, 2020

I have EAP. If at the time of my purchase I had the option to pay just $2k for AP/TACC, rather than $5k for EAP, I definitely would've gone with just AP/TACC.

To answer your question, yes I think it's worth the $2k to go for it. It is awesome to have when sitting in traffic, or when you want to open the water bottle to take a sip. I definitely would if I was in your situation.

geedub1023 | June 26, 2020

Thanks h2ev. Do you know if AP/TACC will stop at stop signs or not?

rxlawdude | June 26, 2020

AP/TACC does not stop at stop signs.

Jaganjai | June 26, 2020

I would recommend against getting it. You only live once and I have had numerous occasions where AP was untrustworthy on CO roads. I now use it < 10% of the time and with 110% focus on the road while in use. The technology simply isn't reliable yet.

TeslaDvr | June 26, 2020

If you drive highway a lot, you may benefit from it. For short distance driving and city driving (where there are a lot of traffic lights and stop signs), it's not that useful.

hokiegir1 | June 26, 2020

Mostly +1 @TeslaDvr, except if your city/short distance driving involves very heavy traffic. Then, even with traffic lights, it's still helpful because you can use the car in front of you to stop for signals most of the time.

FISHEV | June 26, 2020

Even though it has its flaws, I’d get it.

You are really getting Adaptive cruise and AutoSteer.

Both are Beta products and have quirks, adaptive cruise, Tesla’s TACC, has issues with Phantom Braking. Google Tesla Phantom Braking and you will see hundreds of threads on the topic on all the Tesla Forums. It brakes for overpasses, other cars safety in their lane and for some WTF reasons. You have to be alert for it.

Also it uses map data for speed limits so you go to set the speed 60 mph and it will jump it to 70 mph if it thinks that’s the speed limit. Also it will brake suddenly if the speed limit is 70 mph but it thinks it’s 50 mph.

AutoSteer works well but Lane Keeping does not.

On the plus side adaptive cruise (TACC) will control you speed and be a nice convenience, just not as stable as you may be used to other cars.

h2ev | June 26, 2020

+1 @hokiegir1, even without traffic light recognition, in city traffic inching along, TACC will still be useful as I've done a few times in NYC. Just be very careful if you happen to be first at the light.

geedub1023 | June 26, 2020

Thanks for all your comments/inputs!

One more dumb question from me...does the Navigation of the M3 communicate with the AP/TACC? In other words, if I'm using AP/TACC and I engage Navigation to get me to a location will the car exit the highway and make turns to get me to my location?

M3phan | June 26, 2020

geedub, right now, yes and no, it will navigate to your Destiination as far as taking you along the highway’s, navigating any relevant inter-changes, and then automatically exiting down off of the exit ramp, at which point you will have to take over steering on local city streets to get to your Destination. (FSD will eventually add the auto navigation turning on city streets as well.)

To answer your original question, I would get the AP upgrade simply for the benefit of letting the car handle the stress of rush-hour stop-n-go traffic. That is truly a blessing to my high blood pressure. : )

M3phan | June 26, 2020

Actually let me self correct what I just said… You have to have navigate on auto pilot functionality for all the automatic navigating on highways, interchanges, and ramp exiting. Regular AP/tacc will not do that

jmccpa | June 26, 2020

If I did not have it but experienced it, I would definitely opt for it. I have had a minimum of phantom braking - maybe 10 times in 6 months of driving with it.

I find auto steer (lane keeping) to be excellent both on freeways and city streets. No ping-ponging at all.

It is particularly beneficial in stop and go traffic. 2019 M3 LR RWD. 6,600 miles.

andrew | June 26, 2020


Just got mine several days ago.
For me, I don't trust the reliability of the AP after a few incidents but in all honesty, I do enjoy it if I'm on an open road. If you get it, you will have to recondition to new and safer driving techniques and be alerted all-time for any unforeseen circumstances. You have 2 days to try out and cancel it if needed.

geedub1023 | June 26, 2020

@M3phan Thanks. So, basically FSD is needed for that capability?

@jmccpa Any pattern when the phantom braking occurred? Seems like I read that some overpass shadows were some causes.

wiscy67 | June 26, 2020

@geedub1023 changing lanes is all part of FSD. AP is auto steering within your lane and traffic aware cruise control / auto braking. You'll still have to have hands on wheel applying some torque.

FISHEV | June 26, 2020

@geedub1023 | June 26, 2020 One more dumb question from me...does the Navigation of the M3 communicate with the AP/TACC? In other words, if I'm using AP/TACC and I engage Navigation to get me to a location will the car exit the highway and make turns to get me to my location?“

No. That is Navigate on AutoPilot which is “Full Self Driving” product, not to be confused in any way with full self driving, and that is an additional $7k. You need to by AP for $2K to spend $7K for FSD.

geedub1023 | June 26, 2020

Got it! Thank you andrew, wiscy67 and FISHEV.

M3phan | June 26, 2020

@ geedub, correct

rehutton777 | June 26, 2020

I bit on the offer and paid the $2K for AP. Took the car out to test it out. I am probably the outlier here, but after putting it through its paces, I have decided that it's not for me. I am retired and have no daily commute, and actually do most of my driving on city streets and highways - - very small percentage of driving on freeways. When testing AP function on non-access controlled roads (e.g. Santiago Canyon Road in OC for those who know the area), I was alarmed at how the car responded to lane markings. My grandson was with me for the trial, and he was frankly scared to death. I know that Tesla says that AP is designed for use only on freeways and other similar access-controlled roadways, so was not surprised that the car had some issues with curves and road markings on this type of highway. I also took it on the freeway (I-5 in south OC), and found the car did just fine. I was somewhat disappointed that the car would "kick" out of AP when I signaled and performed a lane change on the freeway, but know that, based on other's comments, that would be the case. It forced me to have to re-initiate TACC and auto steer each time.

It is probably a very valuable feature for those who have significant freeway commutes, and if I were in that category I would most likely keep it. However, for me it did not seem that, for the amount I would likely feel comfortable using AP in my mostly non-freeway driving, that it is worth the $2000 investment. Call me weird, but I am going to cancel the purchase within the allotted 48 hr. cancellation period. It was great to actually try it out, though - - thank you Tesla!

jmccpa | June 27, 2020


Yes, the few times I had the phantom braking was going under a freeway overpass. But, again, rare to occur for me.

RayNLA | June 27, 2020

Get it!
Even if you don’t use it your vehicle will be worth more at trade in/private sale or insurance claim. But I’m willing to bet that once you have it and understand its nuances and limitations you will be happy that you purchased it. It’s definitely worth 3k and a deal at 2!

RayNLA | June 27, 2020

Get it!
Even if you don’t use it, your vehicle will be worth more at trade in/private sale or insurance claim. But I’m willing to bet that once you have it and understand its nuances and limitations that you will be happy that you purchased it. It’s definitely worth 3k and a good value add at 2.
Thank us later!

loosej89 | June 27, 2020

If, when you drive, you like to use cruise control, then yes , get it, I find that it works very well. Works especially well with other cars near you, like on bumper to bumper freeways. You can set your following distance and relax, it will keep that distance well for you. Mine rarely phantom brakes.

WW_spb | June 27, 2020

Drove round trip Ga-NJ 1800miles on AP and it was excellent! It really does makes huge difference bc you get a break behind the wheel and arrive more rested than if you didn't use it. City driving depends on where you use and if you know the limits of the system. I use it on two lane roads often and not so much on single lane roads. Stop and go traffic is excellent with AP on.

WW_spb | June 27, 2020

So, Yes get it while let it is on sale.

davester | June 27, 2020

So I recently purchased basic AP for $2k but I keep getting "Autosteer is temporarily unavaible" anytime I try to enable it. TACC works great though. Anyone have a similar experience? What is the trick to get autosteer to work? [Note: Yes, I have enabled autosteer in the settings screen.]

WW_spb | June 27, 2020

Scratch "let"

WW_spb | June 27, 2020

Did you drive long enough for the system to calibrate?

davester | June 27, 2020

I think so, yesterday alone I drove about 100 miles and still no go on various different highways/freeways, unless I need to manually tell it to calibrate. I don't see any other more detailed error messages like a sensor problem or anything either, though I am new to the AP side of things so I don't even know if that is something that would display on the car screen.

geedub1023 | June 27, 2020

UPDATE: I took the plunge. I just paid $2170 (includes tax) for this AP/TACC upgrade. Can't wait to try it out!

Thanks for everyone's inputs....both for and against it. What sold me was hearing the comfort level achieved by many of you using it on long drives. Although, I don't do it that often, with this enhancement I will definitely be more willing to take my M3 on longer road trips now.

WW_spb | June 27, 2020

Congrats. Smart move.

M3phan | June 27, 2020

Congrats and enjoy!

Blue Shift | June 27, 2020

I just purchased it as well. At $2K, this is a very good investment, while $3K was a bit expensive for the TACC & auto-steer, IMO. It's very nice for long-distance highway drives (know from the trial periods Tesla offered last year).

bryan.whitton | June 28, 2020

I bit yesterday. Took it for a 20 mile drive to check it out. It actually works a little better than the 30 day trial i had when I purchased my car.

geedub1023 | June 28, 2020

I used TACC today driving to work and really liked it. The car hasn't calibrated yet due to the limited miles I've driven it since I bought these capabilities so I haven't been able to use the AP feature.

M3phan | June 28, 2020

Oh man, you will LOVE AP in stop n go traffic. Let’s us know how that goes!

geedub1023 | June 30, 2020

@M3phan I used AP for the first time today. It was a little weird because it wasn't highway lanes I drove on but two lanes on each side of a median with several stop lights along the way. Not being used to it, I have to admit a little anxiety on whether the car would navigate turns without bumping the curbs and the painted center lines were light and weathered so I worried the car would drift over to the next lane, etc. It did great and I know the more I use it the more comfortable I'll get!

Once again, great investment IMO!

wiscy67 | June 30, 2020

Has anyone done an efficiency comparison of using AP vs not such as for a daily commute? I'd be interested to see if it works efficiently as measured by the current trip card efficiency (wh/mi) both with and without AP for the same conditions.

FISHEV | June 30, 2020

@geedub1023 “ What sold me was hearing the comfort level achieved by many of you using it on long drives.”

If you’ve never had adaptive cruise before it becomes a must have item. Tesla’s adaptive cruise has issues but still better than regular cruise.

Big_Ed | June 30, 2020


Adaptive cruise is one of those things you wonder how you ever did without.

Where Tesla AP shines over most other cars is slow speed performance. TACC on most cars I've driven shuts off below 35mph. Driving hands off in stop and go traffic is a huge stress relief if your commute involves heavy traffic.

M3phan | June 30, 2020

@geedub1023, sweet! Yeah I remember my first few forays into AP when I first got my car, and it was a weird thing to trust the machine over the self, but it didn’t take more than about a couple of days of regular usage to feel comfortable with it. Glad you’re enjoying it.

FISHEV | June 30, 2020

@Big_Ed | June 30, 2020 “Where Tesla AP shines over most other cars is slow speed performance.”

Subaru’s worked at low speed. Don’t see Tesla doing any better at slow speed.

What makes you say Tesla does better at low speed? Compared to what?

jnordland | June 30, 2020

I had a Model S loaner (well, rental from Enterprise through Tesla) for a week. Only dumb cruise control. What a pain in the a$$!! I couldn't wait to get back into the 3. If anyone does any amount of regular highway driving it is a must-have addition. Ignore all the naysayers. Yes, there are some areas where it's not as precise but you quickly learn how to navigate these. If you have a hand on the wheel (as you should) you can always feel when the car might do something you wouldn't expect it to do and immediately take over. I've driven over 40,000 miles now, half of which was on AP, and it's a godsend. I'd never purchase another car without it.

Big_Ed | June 30, 2020

My son's 2020 Honda Civic does not work below 35 mph. I believe Toyota and Nissan have a similar constraint.

I don't claim to be an expert on Subaru, but did a quick search for a user manual. Here is what the 2020 Subaru Outback user manual says about adaptive cruise:

"Advanced Adaptive Cruise Control
This system provides Cruise Control with the ability to keep a safe distance from the car in
front of you. Using the EyeSight® camera, the Adaptive Cruise Control function identifies vehicles in front when traveling at speeds of approximately 20 mph or greater and manages the acceleration/deceleration of your Subaru to maintain a set speed and distance."

That implies it does not work below 20 mph, although I do not know this for a fact.

Also, Subaru Eyesight has a function called "Lead Vehicle Start Alert" that beeps at you if you are stopped and the car in front of you starts moving again. It mentions options, so maybe you can set the option to start moving automatically; I dunno. I read a comment that you can hit the resume button to start moving again, but that was from some years ago, so perhaps that is no longer valid.

What I do know is that Tesla TACC goes all the way down to a full stop, and then starts moving again without any action required by the driver. I like that. A lot.

Techy James | June 30, 2020

I would recommend getting AP for 2K if that is option. But hurry July 1 is only few hours away. If your car has the newer 3.0 hardware, with the latest update I have noticed phantom braking is rare thing for me.
Now granted if I noticed a place where it was common, then I would pop a bug report right after. Then typically patch or two later and that spot is much less likely to have phantom braking. So if you tend to see it in a certain place, then by all means report it.

MyRedM3 | July 1, 2020

I purchased AP yesterday and tried it on a highway and internal roads. It worked flawlessly 95+% of the time. It got confused merging lanes where two lines merge into one on the highway and once when i tried to turn left. Other than that it was smooth. I was surprised when it went to a full stop and pick it from there. I've a Honda and it cant do below 25 mph. Only frustrating part is to have engage Autopilot every time I changed lanes. I wish they allow keeping it active with lane changes. I'm not asking for auto lane changes that is part of FSD.

wiscy67 | July 1, 2020

I held off on purchasing AP with no regrets for my SR+. I just don't use it for my 25 mile one-way daily commute. I do tip my cap to Elon for creating demand through discount promotions and promises for higher future pricing. Today, true to his word, I see pricing of AP $3k and FSD $8K.

Big_Ed | July 1, 2020

"Only frustrating part is to have engage Autopilot every time I changed lanes. I wish they allow keeping it active with lane changes."

To be clear on terms, Autopilot consists of two separate functions: Lane Keeping (LKAS) and Adaptive Cruise (TACC). If you signal a lane change and then turn the wheel, LKAS turns off but TACC stays on. When you are in the new lane, you have to turn LKAS back on manually.

I agree with your wish ... I recently drove a new Nissan, and LKAS turns back on automatically when it senses a new lane. I liked that behavior and wish that Tesla would make it an option in settings. A minor issue though.

MyRedM3 | July 1, 2020

LKAS is not the same as Autosteer, though! Autosteer works much better within the lane. With LKAS you still have to manage the steering actively, at least that's the case with my 2019 Honda. It swill swing you back into the lane if it senses car entering the adjacent lane. Its similar to Tesla's Lane Departure Avoidance feature

Nevertheless, it would be more fun if they enable an option to turn autosteer back on once the car is in a new lane.

geedub1023 | July 1, 2020

@MyRedM3 Hoping a future software update includes the ability to change lanes while on AP and it not be disengaged! Fingers crossed....