Installed two new Michellin primacy mxm4 GREEN on the back - now car unstable

[Super_Popular]

who needs tires!?

TESLA MODEL S 21" TIRES

 

[wk057]

I've gone through several tires in the past couple of years. I usually end up with a nail or something in one, or hit a bad pothole, or whatever, causing me to have the two rear or two fronts replaced. Never had any issues. I've also saved the good one of the two tires and have been able to use my extra one once so far without issue as well. Both on the P85D and wife's P85.

 

[jerry33]

I've been struggling to understand how an incorrect torque value on some of the wheels would cause unstable handling.

I guess if the lug nuts loosened and backed off their seats it would be possible but just an incorrect torque - say 80 vs 130? Sorry, I don't see it.

Torquing of the lug nuts creates a certain amount of "pre-stretch" in the bolts. If they are not up to spec, then the stretching occurs dynamically during vehicle operation causing instability. There are several instances of this happening which have been posted on TMC. The Model S is a heavy car with high motor torque so the wheel nut torque values need to be high (a Corvette has similar lug nut torque values).

 

[pdx4s]

so I took a snapshot of one of my morning commutes energy consumption this week to show the issue of slow vs fast driving vs energy consumption with notes with street driving (30-40mil/h), then starting on the why ramp and then driving on the hwy speed showing a drop down curve of the E/m (not sure the pic is large enough)

:

Torque was 130lb-ft as they were told for the MS.
thx

 

[jerry33]

That looks very much like battery heating.

 

[pdx4s]

preconditioning is set to On, night charging is completed <1hr before departure, MS settings are the same before and after the tires change, temp. dropped by 10-15F but that still doesn't explain to me the 20% increase in e/m

7.0 ?

I'm expecting a direct proportional e/m curve: lower speed=lower e/m, this shows an inverse curve...

 

[TexasTeslaRacing]

Last week I visited the SC for two new tires. I requested the rears move to the front and the new tires go on the back. When I picked up the car, they placed the new tires on the front. I have Michelin Primacy MXM4 19'' and AWD P85D. The tires on the rear have about 8/32". To me it seems like the new tires should go on the rear. Anyone also feel the same?

 

[scottm]

I have RWD so rubber with more tread always goes to the back.

You have AWD, and I'm not sure of the wear differences front-to-back.. maybe they wear really evenly. I'd be surprised if this hasn't been covered already in another thread.

 

[st50maint]

I have RWD so rubber with more tread always goes to the back.

You have AWD, and I'm not sure of the wear differences front-to-back.. maybe they wear really evenly. I'd be surprised if this hasn't been covered already in another thread.

At 26,000 miles I had the first ever tire rotation on my 70D.

The front two tires were worn down to 7/32.
The left rear was at 6/32.
The right rear was at 5/32.

The tires were not rotated at my first annual service (12,500 miles) because Tesla said all tires were evenly worn.
I asked the sevice advisor why the right rear was worn so much. He claimed that the right rear is where the most power is applied.

 

[habanero69]

At 26,000 miles I had the first ever tire rotation on my 70D.

The front two tires were worn down to 7/32.
The left rear was at 6/32.
The right rear was at 5/32.

The tires were not rotated at my first annual service (12,500 miles) because Tesla said all tires were evenly worn.
I asked the sevice advisor why the right rear was worn so much. He claimed that the right rear is where the most power is applied.

Most power to the right rear? That's BS. Should be even unless you are doing constant left hand doughnuts or running on a oval track like Indy.

 

[scottm]

Not necessarily BS.

The transaxle has to accommodate differential slip... which changes the amount of torque delivered per wheel.

If you turn off traction control and floor a Tesla RWD ... which wheel spins first? Try on a variety of surfaces and do some slow motion capture. Right rear anyone?

 

[wycolo]

> The transaxle has to accommodate differential slip... which changes the amount of torque delivered per wheel. [scottm]

Transaxles can have clutch plates installed which tends to equalize torque delivered to the wheels. Motor is axially transverse so doesn't affect traction. I believe your observation re right wheel always breaks traction first (believe you to be a truth teller). So I must be missing something crucial about how TC operates in the RWD ModelS. . . mmm . . .
--

 

[Xenoilphobe]

Check the lug nut torque.

 

[skhenry81]

I'm dealing with the same issue right now. I just took my winter 19" rims and tires off and replaced them with brand new 21" rims and tires. Both sets were purchased from Tesla. I am having the same unstable feeling while on the Highway. It feels like the car is going to tip over when switching lanes....I know the rims were installed correctly because it was done by a Tesla technician. I have done about 200 kms since putting them on. Does anyone have a fix for this? I'm planning on going in for an alignment.

Thanks