Traction Control/Swaying under Firmware v4.2 ?

[dtich]

i'm confused as to the definition of "swaying". is the car rocking from side to side? are the rear wheels slipping?

no, it's a slight suspension weave (not dangerous at all, imo), more toward the front end if i remember -- but no slipping or traction issues at all.. and, fwiw, i have the distinct impression that this is ameliorated in 4.2 for me. i feel like this is/was stability control compensating for perhaps a slight oversteer on my part when i change lanes at speed. maybe i've adjusted my driving a wee bit, with a mite less steer when doing quick maneuvers, but not consciously. as we know, getting used to a new car takes a bit of time. this may be one of those things that didn't register with my body at first and i've been still driving as i did with the bmw. i don't have the issue anymore that i can tell and i still drive as racy as ever. maybe it simply took a bit to understand how the s responds in that situation and undo old muscle memory. (i have steering on sport btw.)

(side note: had occasion to drive my x5 over the weekend, it's getting turned in soon, and while that is a great car, it felt so sluggish and clumsy compared to the s... breaks my heart to say, but didn't miss it at all! sorry old girl...)

 

[Doug_G]

I'm suspecting this may be driver induced. The steering gets light when you're under hard acceleration, due to weight transfer, and when you have the steering set to Sport it's pretty sensitive. It's possible that the g-loads might cause your arms to pull on the wheel asymmetrically. Then you start correcting automatically, and under these conditions the steering is very sensitive and it's rather easy to over-correct.

 

[RedSoxDoc]

I can only speak for myself (which I pointed out earlier in this thread) but this has nothing to do with being driver induced. Someone did say that you get similar acceleration and torque without having to press the pedal down as far. I do agree with this since the 4.2. I think that the is accentuated for those of us with the performance model. Perhaps anyone commenting from this point should specify and maybe we can tease out some additional information. I can attest that the little bit of fishtailing is indeed a little concerning. I have driven many cars with better acceleration (Nissan GT-R, Ferrari 458, Aventador, McLaren) and did not feel such fishtailing. With that being said this car is 100% bad ass and incredible. I'm not complaining at all. Just pointing out something I seemed to notice with the 4.2 upgrade.

 

[aviators99]

I am far more aware of the placebo effect than most (old hobby), and was very careful in my wording because of it. But similarly, you not noticing a change doesn't mean it is not there.

Although it could mean the change was in a different place. I skipped a few releases; I went from 1.15.14 to 4.2, so it's possible the changes, if any, were in some earlier transition that you never saw.

I was also the one that said "stronger and weaker" in a whimsical sense. I then went on to explain that it's just as strong or stronger; it just ramps up slower, so it might feel weaker at first. While (as I noted before) I can't swear it's the case without driving both versions back to back in identical conditions, I think it's a perfectly reasonable perception, and something that Tesla could well have wanted to do.

I agree with everything you say, and I think my wording was also carefully worded to state that it's my opinion and I could be wrong.

 

[jerry33]

@roblab I certainly take your point that it's better to anticipate and drive more smoothly. However, I wasn't moving the steering wheel at all (to my knowledge) when it started to sway. It felt like it was more a function of the rapid acceleration making the front end lift and drift slightly.

Try driving with one finger (No, not that one). In some cases your muscle memory moves the steering wheel without you being aware it. This was noticeable when cars changed from bias-ply to radial tires. Some people described the same kind of swaying that you experienced when they first switched to radial tires. It turned out that they were unconsciously moving the steering wheel as the felt the irregularities in the road. Driving with one finger eliminated the muscle memory movement.

 

[Jcmason]

i'm confused as to the definition of "swaying". is the car rocking from side to side? are the rear wheels slipping?

@kinddog There wasn't any rocking and no, the rear wheels were not slipping. It felt to me like the nose had lifted, the front wheels had less traction and the front of the car swayed quite rhythmically left then right then left then right over the course of maybe 100 yards. In some ways, it felt a little like aqua planing, and stopped as soon as I lifted up on the accelerator. The car is a non-performance with air suspension and 19" wheels with all season tires.

- - - Updated - - -

Try driving with one finger (No, not that one). In some cases your muscle memory moves the steering wheel without you being aware it. This was noticeable when cars changed from bias-ply to radial tires. Some people described the same kind of swaying that you experienced when they first switched to radial tires. It turned out that they were unconsciously moving the steering wheel as the felt the irregularities in the road. Driving with one finger eliminated the muscle memory movement.

Hmm, interesting suggestion. I'll happily give it a try. I do think it takes a little time to get used to driving any car, but especially one as unique and powerful as the Model S, so it could be that I'm not quite in tune with it yet.

 

[gtimbers]

Keep in mind that even with the 21" wheels, the Model S is under-tired for its weight and power. Probably should be at 265's in the rear at least. It also wouldn't hurt if the rims were a bit wider. Most of the high end competition has more rubber. I'm sure the decision to go with 245's was a compromise between handling (stability) and energy consumption. Some of the squirrelly behavior can also be due to the specific tires chosen. The 19" Goodyears are nothing special. The 21" Continental's are not known for precision either. Both are more ride and wear oriented. I doubt that much more can be done with the stability tuning to further compensate for marginal amounts of slightly squirmy rubber. I feel Tesla did a great job for the majority of us. Those desiring the next level of handling might consider wider rims and tread along with better rubber. It will cost range, but nothing is free when physics is involved.

 

[Jason S]

My wife informed me that we got our first update in months -- turns out 4.2 was downloaded last night and I had it installed this evening.

After reading this thread, I figured I should go give it a shot. Haven't driven Angelique since this weekend, but have plenty of seat time with the pre-4.X release now.

Acceleration is snappier and ... floaty-er, as others have tried to explain. I think the more immediate torque is lifting the front a bit more than before and the TC is actually more responsive. "More?", you ask. Oh yes indeedy.

I used to be able to swing around any sharp left or right and the TC would skitter around before settling in. Now she's just stuck. I see the TC indicator come on, but the skitter doesn't happen. There is something like torque steer available. It is different but there isn't any loss of control that I can tell, seems better to me.

I think the difference is the more responsive throttle makes the car feel a little less 'grounded' and that can be disconcerting for those not used to it. Overall I like the slightly changed throttle response though; it is even more immediate throughout the range.

 

[Zapped]

Those with TC problems, do they use 19" or 21"?

19" have less traction and the tires can compress more (bigger sidewalls)
And wintertires are mushier than summertires

I'm on the 21" summer tires, driving in -20C conditions but no fresh snow but some dry, some hard pack snow, so I'm particularly sensitive the spin out, fish tail.
I noticed that change in humidity is definitely a factor, with variations in Edmonton from 30 to 90% RH
Also, the car tends to swing left ( drivers side ) before the TC kicks in and straights out but only if I accelerator hard.
No difference between 4.1 & 4.2
It reminds me of the other RWD cars I have owned, so no issues for me and am very happy with the Model S.

 

[brianman]

After another ~150 miles of driving post 4.2, I don't notice a difference between .31 and .42 in driving experience (not sway, not throttle, not regen strength). Just another data point, I know.

 

[IndigoAE]

My Model S does this all the time. It feels very unsafe. I've owned/driven many RWD cars that are faster than the Model S, so I'm not buying any of this nonsense about it being a normal characteristic of a powerful RWD car. I've had a few friends comment on it as well when they've driven my car. I hope Tesla figures out a fix for this. My guess is that it is related to the crappy air suspension.

You guys say it feels very unsafe and feels out of control but no one has complained about any actual loss of control or pulling out of a lane etc. imo this means the traction control is perfect. It pushes to the edge and that's it. Traction control that doesn't do this will just cut your power more. I know I didn't spend 100k on a performance sports sedan to have my only choices be grandpa mode and risinrisking death mode. Maybe in the future Tesla will add a third mode that'll help you "feel safe" and relegate the existing one to sports traction control.

 

[dtich]

You guys say it feels very unsafe and feels out of control but no one has complained about any actual loss of control or pulling out of a lane etc. imo this means the traction control is perfect. It pushes to the edge and that's it. Traction control that doesn't do this will just cut your power more. I know I didn't spend 100k on a performance sports sedan to have my only choices be grandpa mode and risinrisking death mode. Maybe in the future Tesla will add a third mode that'll help you "feel safe" and relegate the existing one to sports traction control.

this is the most overblown thread... the internet is crazy. like whisper down the lane played by senile old coots.

 

[derekt75]

I used to feel the swaying quite often. I thought it felt like torque steer, which is odd for a RWD car. It didn't feel dangerous to me, just a bit unsettling.
I switched the steering from sport to standard, and I haven't much noticed it since.

Are most of you using sport?

 

[Lloyd]

I believe what you guys are feeling is the stability control trying to kick in and not the traction control. JMO!

 

[William3]

You guys say it feels very unsafe and feels out of control but no one has complained about any actual loss of control or pulling out of a lane etc. imo this means the traction control is perfect. It pushes to the edge and that's it. Traction control that doesn't do this will just cut your power more. I know I didn't spend 100k on a performance sports sedan to have my only choices be grandpa mode and risinrisking death mode. Maybe in the future Tesla will add a third mode that'll help you "feel safe" and relegate the existing one to sports traction control.

Maybe you guys are misunderstanding the situation. The swaying happens when I accellerate in a straight line, the steering wheel is perfectly straight the whole time. And don't flatter yourself by thinking it's just a result of the Model S having mountains of torque. This issue happens even at higher speeds, where the Model S couldn't spin the tires even in its wildest dreams. I'm not suggesting any sort of software fix (grandpa mode as you call it). I don't believe it is related to traction control at all. I think it is a hardware problem. I predict that the non-air-suspension cars will not have this problem.

 

[dave]

The issue (at least for me) is not the traction control. I have no issues with tire traction. It is with the suspension feeling "floaty" or like it's swaying laterally while accelerating and turning (such as with a relatively high speed lane change).

I did some "slalom" type moves on the highway the other day, just moving left and right while doing about 75 MPH. (The folks behind me I'm sure thought I was drunk). You can partially recreate the feel just by doing that without any acceleration changes. After making a move to the left or right the suspension seems to try and correct you the other direction which leads to the swaying sensation.

Again, this is just my opinion and experience. I am not saying the sky is falling or the car is unsafe, but the feeling is there. I am not a race car driver. My old car is a RWD Infiniti G37S with 300+ HP however and I do not have that "sway" feeling while making high speed maneuvers.

 

[Hank42]

I believe what you guys are feeling is the stability control trying to kick in and not the traction control. JMO!

Lloyd, yes, - you are right, it's not traction control kicking in - this behavior occurs with traction control on or off - it's the stability control or the suspension setup.

 

[CanuckS#69]

For those that have experienced the swaying, have you checked your tire pressures? I have experienced a reaction like you describe, but I found that my tires were all at 39psi. I haven't been able to reproduce the same effect since bringing them all to 45 (19" winters). I suspect that the pressure was set originally in a nice warm shop.

 

[Hank42]

For those that have experienced the swaying, have you checked your tire pressures? I have experienced a reaction like you describe, but I found that my tires were all at 39psi. I haven't been able to reproduce the same effect since bringing them all to 45 (19" winters). I suspect that the pressure was set originally in a nice warm shop.

What screen can you check your tire pressure on? Oh wait, do you mean, GASP, actually getting out of the car and kneeling down at at each wheel and checking the tire pressure?!?!?! LOL
[I CANNOT BELIEVE THIS CAR DOES NOT DISPLAY THAT INFORMATION ON THE SCREEN!]

 

[FlasherZ]

Maybe I'm one of the rare ones, but the car behaves as expected for me. The stability control unfortunately shuts down a few attempts on my part at controlled aggressive driving, but when I get behind the "go" pedal aggressively, my car reacts as any other 4xx-ft-lb.-of-torque car does. If you're loose with your steering, it will sway. If your tire pressures are out of balance you'll feel "torque steer".

If you hold on tight, control your steering (it's too easy to subconsciously try to correct which creates sway - the 'single-finger' trick earlier is key), v4.2 is a vast improvement and shoves Model S into a higher rank than earlier software releases. My opinion, of course.