Car doesn't feel stable at freeway speeds

[FlasherZ]

I can't really say that I feel the car is ever out of control or needs too much input - both my Sig P85 and the loaner P85+ (1 1/2 weeks, 700+ miles) track very well and handle remarkably well. Around curves, I hold it and stick to the road well while holding the wheel steady, none of the "racing wheel" action, even at 65-70 mph on curves where advisory speed is 45-50.

My money is on something not quite right in your car's setup.

 

[mknox]

It's a strange feeling. The car doesn't feel stable at freeway speed on sweepers, on-ramps, off-ramps... The feeling is similar to (as described by others on this forum)... 'busy steering' or 'hunting'. The car never seems to settle into a turn and requires continuous steering input, and especially steers itself with *light* accel or decel. Definitely not talking about heavy throttle inputs or sudden lift-throttle scenarios.

Same here. Not NEARLY as stable or planted as my previous Cadillac CTS. In all fairness I have not reported this to Tesla but have checked tire pressures and lug nut torque (all good). I suspect it an alignment issue and will eventually get around to having it dealt with.

 

[montgom626]

Not sure what the issue is but have you called Tesla service or had it evaluated by them? That might be a good place to start.

Sounds like the first step.

 

[ModelS8794]

Ditto what Todd Burch said, my S85 with 19s drives like it is on rails. I just did 450+ highway miles this weekend, avg speed 75mph. I have had the rear lug washer service bulletin done, when my tires were rotated at 6000 miles (now at 7500).

Jake did you do tire rotation/lug nuts at a Tesla SC? And was it complimentary part of the service program? Were you there just for that or other reasons too?

Cheers,
A

 

[wycolo]

With 19s and good alignment (no tire wear issues) I've definitely noticed the OP's need for 'subtle steering corrections'. As opposed to my 2012 Subaru Forester AWD which suffers NO such need for 'steering corrections'. Took off the snows in mid-June and put on the unused OEM Goodyears. Noticed the max pressure on these tires said 51 lbs. So naturally pumped up these to 51 pounds. And homped on the lug nuts (150 ft lbs is not gonna hurt these bad boys!). Result is a definite improvement in the steering, ie not part of trip consciousness any longer. 85kwh with steering always in middle position, 8000+ miles. Btw, range mileage has markedly improved this summer.

Suggestion: Rotate new tires @2500 miles. Avoid/discover any issues early on!!
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[mnx]

With 19s and good alignment (no tire wear issues) I've definitely noticed the OP's need for 'subtle steering corrections'. As opposed to my 2012 Subaru Forester AWD which suffers NO such need for 'steering corrections'. Took off the snows in mid-June and put on the unused OEM Goodyears. Noticed the max pressure on these tires said 51 lbs. So naturally pumped up these to 51 pounds. And homped on the lug nuts (150 ft lbs is not gonna hurt these bad boys!). Result is a definite improvement in the steering, ie not part of trip consciousness any longer. 85kwh with steering always in middle position, 8000+ miles. Btw, range mileage has markedly improved this summer.

Suggestion: Rotate new tires @2500 miles. Avoid/discover any issues early on!!
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I found I had more grip with the car handling bumps better if I lowered the tire pressure... lol ~40psi is just about right from what I found when taking tire temperatures

 

[mknox]

I found I had more grip with the car handling bumps better if I lowered the tire pressure... lol ~40psi is just about right from what I found when taking tire temperatures

That's interesting. I've been keeping mine at the recommended 45 PSI and have found the car is quite harsh over bumps. Do you get TPMS warnings with the lower pressure? I wonder if range is sacrificed (more rolling resistance).

 

[ElSupreme]

Have you tried changing the steering settings? I find sport to be very twitchy. I also find the seats lateral support a little lacking (and the seats themselves a little wide), causing me to use the wheel for body support.

If you change the stering to medium or light (I forget the real names) you might see this issue disappear.



I also think this car picks.up crosswinds way more than I imagine it would. For as heavy and low as it is the wind can really move this car.


l




Just a thought. I you are really having a problem I would keep taking it in. And try to repead the sensation and ride with a Tesla tech, to point it out.

 

[mnx]

That's interesting. I've been keeping mine at the recommended 45 PSI and have found the car is quite harsh over bumps. Do you get TPMS warnings with the lower pressure? I wonder if range is sacrificed (more rolling resistance).

Last time I went to the track, I lowered my pressures to 38f and 40r which I found to be a hair underinflated when using an IR gun. I didn't get any TPMS warnings. When driving home I could definitely see the increased rolling resistance. I couldn't hit rated consumption, even while traveling at <90km/h.

 

[wycolo]

Pump up to 51 pounds when you leave track to go home. You'll be amazed at the efficiency, and may be surprised that there is no resultant harsh ride. YMMV of course.
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[JakeP]

Jake did you do tire rotation/lug nuts at a Tesla SC? And was it complimentary part of the service program? Were you there just for that or other reasons too?

Cheers,
A

I happened to be near the SC on a business trip, and had prepaid for the Service Plan (including Ranger visits, since I live far from an SC). The primary reason was to get the tires rotated. They did some service bulletin work, and gave me a new UMC, since mine was old and finicky, and missing the metal handle plate.

 

[mknox]

Last time I went to the track, I lowered my pressures to 38f and 40r which I found to be a hair underinflated when using an IR gun. I didn't get any TPMS warnings. When driving home I could definitely see the increased rolling resistance. I couldn't hit rated consumption, even while traveling at <90km/h.

Thanks! Good to know. I guess I'll just stick to the recommended pressures as I'd rather not sacrifice efficiency. (If the ride had been smoother with no loss in efficiency, I might have tried it).

 

[Dreamin]

Thanks for everyone's insights.

I'll start with lug nut torque/alignment check/any suspension recalls and see if that fixes the problem. I'm not opposed to changing the tires, as some have suggested, as the next step.

 

[gtimbers]

Having owned 3 different 5 series BMW's, several Lexus, several Infiniti's, a Saab 9000, Acura Legend, Mini and Fiat X19 in addition to some less notable vehicles, I find the Tesla to be twitchy at speed (60 - 80 mph) compared to all of the above. Above 100,it's downright difficult to keep going straight. In addition to the front-end drift, the rear end steers itself a bit making for a wild ride at speed. Using sport steering weighting is essential to keep the car in a lane. One of my BMW's was a 540i sports wagon. Great car. It had the infamous excessive camber issue in the rear but, fortunately it was adjustable. I took it to the minimum (about 1 degree) and the wear problem went away. At the same time, the alignment guy suggested going to 0 deg toe in the front. I let him do it and found that the formerly stable car now drifted, not unlike the Tesla. I have been toying with adding a little toe to the front but I haven't done it yet for fear of losing range. The rear end, however is another issue. I typically stay well below 80 so the problem is not a big deal for me. I just had to test top speed and such initially.

 

[wycolo]

> I find the Tesla to be twitchy at speed (60 - 80 mph) compared to all of the above. Above 100,it's downright difficult to keep going straight. In addition to the front-end drift, the rear end steers itself a bit making for a wild ride at speed. Using sport steering weighting is essential to keep the car in a lane. [gtimbers]

This is a car that your alignment guy needs to get his hands on. If mine did all that . . .
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[jerry33]

> I find the Tesla to be twitchy at speed (60 - 80 mph) compared to all of the above. Above 100,it's downright difficult to keep going straight. In addition to the front-end drift, the rear end steers itself a bit making for a wild ride at speed. Using sport steering weighting is essential to keep the car in a lane. [gtimbers]

This is a car that your alignment guy needs to get his hands on. If mine did all that . . .
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Right. The first thing I would do would be to dial in more caster.

 

[Colasec]

I took my three-week-old Model S in this week for an alignment since it would pull to the right at highway speeds. Can someone please translate these numbers? What does "actual" vs "before" mean? Can you tell how the car might have felt before its alignment and how it might feel now?

 

[simplesolar]

actual means after alignment
before means before alignment

red means out of spec
green means within spec

Interesting how your specified range is different than mine. The alignment looks ok to begin with not too bad. I suspect your steering wheel was probably off like mine. They realigned the car with the steering wheel and it drives straight as an arrow now.

 

[Colasec]

actual means after alignment
before means before alignment

red means out of spec
green means within spec

Interesting how your specified range is different than mine. The alignment looks ok to begin with not too bad. I suspect your steering wheel was probably off like mine. They realigned the car with the steering wheel and it drives straight as an arrow now.

Thanks. It does drive straight now.

 

[AnOutsider]

How is at highway speeds?