out of spec tire size and traction control

[Atraf]

I have been running 255 40/18 for approx. 30,000 miles with coil over, slightly lower and switched to 265 40/18 since January. No problem at all.

That makes perfect since considering:
255/40R18, Diameter: 26.0", Rev/Mile 775
265/40R18, Diameter: 26.3", Rev/Mile 766

And from earlier comments we know that
245/40R19, Diameter: 26.7", Rev/Mile 755
Works perfectly, since they are all smaller than:
255/45R18, Diameter: 27.0", Rev/Mile 746
Which is known to work (either in ET+28mm / 18x8.5J or in ET+30mm / 18x9.0J)

I still wonder about:
255/40R19, Diameter: 27.0", Rev/Mile 746
265/40R19, Diameter: 27.3", Rev/Mile 738
Specifically about their compatibility with the 19" sport wheels (ET+40mm / 19x8.5J) I suspect that they would be touching the front upper knuckle as I have yet to see any one that comment on having that setup other than in the post that @superflyrolla linked where @Ari00 wrote that they have the former on.

 

[ShaolinEV]

@ShaolinEV What wheels or width + offset? How much camber are you running? (I think those questions are needed to fully understand the example of your fitment.)

ESR RF1 18X9.5 35mm with Mountain Pass Comfort Coil over.

 

[Atraf]

That makes perfect since considering:
255/40R18, Diameter: 26.0", Rev/Mile 775
265/40R18, Diameter: 26.3", Rev/Mile 766

And from earlier comments we know that
245/40R19, Diameter: 26.7", Rev/Mile 755
Works perfectly, since they are all smaller than:
255/45R18, Diameter: 27.0", Rev/Mile 746
Which is known to work (either in ET+28mm / 18x8.5J or in ET+30mm / 18x9.0J)

I still wonder about:
255/40R19, Diameter: 27.0", Rev/Mile 746
265/40R19, Diameter: 27.3", Rev/Mile 738
Specifically about their compatibility with the 19" sport wheels (ET+40mm / 19x8.5J) I suspect that they would be touching the front upper knuckle as I have yet to see any one that comment on having that setup other than in the post that @superflyrolla linked where @Ari00 wrote that they have the former on.

I ran my '21 M3 LR on the OEM optional 19s all winter with 255/40 tires and saw hardly any range difference. I am also running MPP sport coilovers and can barely get a finger between tire and the wheelwell, with a 15mm front and 20mm rear spacer with zero rubbing at all.

This basically answer my question and confirms my suspicion: Just like how 255/45R18 requires either ET+28mm on 18x8.5J or ET+30mm on 18x9.0J, 255/40R19 doesn't fit on 19x8.5J with ET+40mm (which is the spec of OEM 19" sport wheels). Instead it requires (according the above) an offset of ET+25mm (which can be achieved with a 15mm spacer), rear I suspect doesn't actually require the 20mm spacer but if I was going for that setup I would probably order one from a store that has good return policy...
Alternatively a slightly smaller offset of 30mm would probably work if the wheels are 9.0J instead of 8.5J with emphasis on "probably"

As for 265/40R19, per the above, an even bigger offset is needed as to clear the front upper knuckle but not sure about wheelwell during full turn.

I placed an order for Continental ExtreamContact DWS 06 Plus 245/40R19, should arrive by Saturday, will post before/after pictures.

Thank you everyone!

 

[superflyrolla]

Sounds like you’re set but for other’s reference, I don’t think you’re right about needing those offsets for 255/40r19.

This is 255/40r19 on +35 9.5 wheels w grey brakes.

 

[Atraf]

Sounds like you’re set but for other’s reference, I don’t think you’re right about needing those offsets for 255/40r19.

This is 255/40r19 on +35 9.5 wheels w grey brakes.
View attachment 830665

If that picture was of +40 8.5 I would have agreed with you, my gut feeling is that its only working due to how wide the wheel is (9.5) which, ever so slightly makes the tire a little wider and a little shorter + that 5mm offset for sure helps.
Essentially if you move the tire 5mm to the right and then make it sick up a little ... it would probably make contact with the upper knuckle.

Another thing to keep in mind is that as the tire spins centrifugal force causes it to expend, mostly at the center, which depending on offset might be okay as it will be pulling away from the knuckle but the closer the knuckle is to the center the worse it would be ...

I do appreciate the photo thought!

@MountainPass So.... when y'all are done with parts for the Plaid Model S, can we get aftermarket front upper knuckle?

 

[scarpiamod3]

I have 245/35 20r with ET 30 20x9's on mine and I don't have any issues. I cant even notice a difference in range.

 

[Atraf]

I have 245/35 20r with ET 30 20x9's on mine and I don't have any issues. I cant even notice a difference in range.

I appreciate the details, but similar to my earlier comment addressed to @superflyrolla, your setup is not apples to apples with the question at hand; would 255/40R19 ET40 19x8.5 fit.
Its great to know that 245/35R10 ET+30mm 20x9.0J works but that doesn't give me confidence to try 255/40R19 ET+40mm 19x8.5J.

However thanks to other comments on this thread I am very confident that 245/40R19 ET+40mm 19x8.5J will work, will post pictures on Saturday with the new setup.

 

[MountainPass]

If that picture was of +40 8.5 I would have agreed with you, my gut feeling is that its only working due to how wide the wheel is (9.5) which, ever so slightly makes the tire a little wider and a little shorter + that 5mm offset for sure helps.
Essentially if you move the tire 5mm to the right and then make it sick up a little ... it would probably make contact with the upper knuckle.

Another thing to keep in mind is that as the tire spins centrifugal force causes it to expend, mostly at the center, which depending on offset might be okay as it will be pulling away from the knuckle but the closer the knuckle is to the center the worse it would be ...

I do appreciate the photo thought!

@MountainPass So.... when y'all are done with parts for the Plaid Model S, can we get aftermarket front upper knuckle?

It isn't off the table!

 

[Atraf]

It isn't off the table!

If you want to setup a pre-order/crowdsource page, I'll place an order right now.
You could even preface it with:
1) Orders are only refundable prior to start of production
2) We will start production once 1,000 orders are place OR January 2024 - which ever comes first

My only goal from this part is to increase the tire clearance, it would be phenomenal if we could get the same clearance that the Model Y has (29" / 255/55R18) but even 27" without needing to change OEM ET+40mm offset would be good (which will enable 255/40R19 or 255/45R18 on OEM wheels) - really, anything in between would do.

 

[dsgerbc]

I'd rather have MPP produce nice-looking wide fenders.

 

[Atraf]

Alright, just got back, have installed Continental ExtreamContact DWS 06 Plus 245/40R19 on OEM V1 19" Sport Wheels on my Model 3 Long Range.
Zero rubbing, too early to tell about highway range but so far all looks good.

Feels a little less bumpy and a little more in control during high curve incline highway off/on ramps.

Honestly the car should come this way.

Oh and, it is not any more noisy then OEM tires despite lack of foam.

Thanks everyone

 

[Perscitus]

Looks good, many of us running 245/40s on early production 'Sport wheels' aka Stilettos with stock or midly modified suspensions. Some have since put 10-30K on since replacing the OE tires, but few, if any, come back to post updates (let's assume no news is good news).

 

[Atraf]

Looks good, many of us running 245/40s on early production 'Sport wheels' aka Stilettos with stock or mildly modified suspensions. Some have since put 10-30K on since replacing the OE tires, but few, if any, come back to post updates (let's assume no news is good news).

I sort of knew the answers before making the thread. The main reason I created it was some BS a Tesla service center rep told me, I also failed to find a definitive post saying everything.

As for coming back, honestly its the least I can do after the help and information that I have been given, snapping a few photos and writing up initial impressions is not really a huge lift.

Tomorrow I'll be doing a round trip that I have done many times before, it usually takes 25% of my battery going one way, or 21% if I go without AC (seriously, not even talking "low" temp .. just 72f @ speed 5/10), it will be interesting to see the results with new tiers. (the method is: precondition battery/ac cabin temp while plugged, unplug and go without stops from origin to destination, note battery % prior to departure and note battery % at arrival with how many miles have it been, no charging during the stay, note battery when starting way back, note battery again on arrival and compare odometer before/after, 100% not relying on car's estimated range)

 

[Atraf]

At the halfway point, the below trip took me from 98% to 72% - 26%, usually it’s 25%
This is mainly very fast highway driving with AC on and wind set to 5/10.

My lifetime Wh/mi is 279… this is 292 which is worse. Not sure if I’m having buyer’s bias but … I much prefer the way the car is now than how it was before (entirely in terms of driving, not speaking of looks).

Lastly:
When I drove similar distance back home from the tire shop, my car was set still to 19” sport
When I got home I changed it to the zero-g wheels as they closet in size to my current tires. This was all yesterday.
Today when I entered the car I had notification saying my TPMS sensor successfully reset.
Not even a mile into the drive my car notified me that “Emergency Breaking is disabled”.
This message was not possible to dismiss, it was located left side of screen under my car’s animation.
Exactly when I hit 25 miles during today’s trip the message went away.
Maybe the Tesla rep once tried this size tiresC got the message and reverted to original size tires before driving 25miles?

More updates to follow

 

[Perscitus]

Adjust the tire type too (to summer/all-season) and a bit later try re-setting the Zero-Gs back to Stilletos and back again (accompanied by all the subsequent MCU resets).

Alsp reset/set custom TPMS 'normal' pressure too with the tires cold but having rolled enough at >20mph to start registering the pressure readings from all wheels.

See if that makes the error go away.

The Zero-Gs are indeed the correct diammeter and revolutions per mile match to 245/40R19s on OE wheels.
However with 2022.20.x, who know what else both the config settings drive in the baclground (thx Tesla).

 

[Atraf]

Adjust the tire type too (to summer/all-season) and a bit later try re-setting the Zero-Gs back to Stilletos and back again (accompanied by all the subsequent MCU resets).

Alsp reset/set custom TPMS 'normal' pressure too with the tires cold but having rolled enough at >20mph to start registering the pressure readings from all wheels.

See if that makes the error go away.

The Zero-Gs are indeed the correct diameter and revolutions per mile match to 245/40R19s on OE wheels.
However with 2022.20.x, who know what else both the config settings drive in the background (thx Tesla).

I will try this today if the message comes back.
Yesterday I did the return route, 56 miles (in 53min) with Wh/mi of 325, went from 60% to 32% so 28% for 56miles or 2miles per 1% ... so my total real life range dropped to flat _200 miles_ for 100% battery which is ... pretty awful.

The message ("Automatic Emergency Breaking is disabled") wasn't present during the day when I drove around town nor for 55.8 miles of my 56 miles trip.... not even when I had to slam on the breaks because an idiot in a model 3 decided to park in a highway fork, only to merge into my lane and start driving (from 0 mph) while I'm at the otherwise left most lane doing the speed limit ... all was well..... until I got to the very last stop sign on my way home, I just did regain breaking with a tiny bit of break and it just suddenly came back up.

Waited to post until today to see what happens in the morning, today: no TPMS sensor messages, no issues with automatic emergency breaking ... if it doesn't come back at all within a week ... I'll be very much happy, otherwise I'll try reset the above wheels back to 19 and then back to zero-g + tpms sensor reset, if that wont do, i'll try setting it as another size (probably starting with 20" sport wheels, and if that fails, the original 19" sport wheels) hopefully it wont come to it and it will just work.

It would such not having automatic emergency break for ... the next 60k miles

 

[Perscitus]

I doubt you will have that issue long term, I have been running 245/40R19s for >5K miles now, high regen, low regen, up and down the ambient and battery temperature and SoC ranges - no issues with automatic emergency braking, regen or real-life range.

 

[Atraf]

Car had no issues today, since I got in and until I got home, all was perfect. Did both highway and city driving.

I didn’t touch the settings since that one time I swapped from 19 to zero-g. It just, by the looks of things, self resolved.

I can’t even say if it’s the tire size, it’s my first time changing tires on this car and for all I know it would have acted the same even if I went with oem size.

I’ll post another update later this week.

 

[Atraf]

Alright, its Friday, zero issues, 245/40R19 on 19" sport OEM wheels works fine, did set car once to zero-g as its the most similar size and that's about it, car complained for awhile but eventually it went away.
Energy consumption is high though, that's the one thing, easily lost ~5-8% range however ... my breaking distance is shorter now and since I am not hurting for range I am happy with this trade-off

 

[SK360]

I will try this today if the message comes back.
Yesterday I did the return route, 56 miles (in 53min) with Wh/mi of 325, went from 60% to 32% so 28% for 56miles or 2miles per 1% ... so my total real life range dropped to flat _200 miles_ for 100% battery which is ... pretty awful.

The message ("Automatic Emergency Breaking is disabled") wasn't present during the day when I drove around town nor for 55.8 miles of my 56 miles trip.... not even when I had to slam on the breaks because an idiot in a model 3 decided to park in a highway fork, only to merge into my lane and start driving (from 0 mph) while I'm at the otherwise left most lane doing the speed limit ... all was well..... until I got to the very last stop sign on my way home, I just did regain breaking with a tiny bit of break and it just suddenly came back up.

Waited to post until today to see what happens in the morning, today: no TPMS sensor messages, no issues with automatic emergency breaking ... if it doesn't come back at all within a week ... I'll be very much happy, otherwise I'll try reset the above wheels back to 19 and then back to zero-g + tpms sensor reset, if that wont do, i'll try setting it as another size (probably starting with 20" sport wheels, and if that fails, the original 19" sport wheels) hopefully it wont come to it and it will just work.

It would such not having automatic emergency break for ... the next 60k miles

AEB disabled is a firmware glitch happening to people with factory size tires these days.

I did a lot of testing recently on my 265/35/19's and determined the wheel setting has 0 impact on the speedometer, switching between 18" Aero and ZeroG wheels and monitoring with a 10Hz GPS it showed the same error at the same speeds up to 85mph (max it would let me set cruise control to in autopilot). ZeroG also showed the same range calculations as the 20" Uberturbines and original performance wheels.