MasterC17
Active Member
I'm not sure I understand. A "wheel calibration" is not going to change the amount of energy the car is using.
What recall are you referring to?
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Effect of wider tires on range
- Thread starter Stefan Voinea
- Start date
I'm not sure I understand. A "wheel calibration" is not going to change the amount of energy the car is using.
What recall are you referring to?
That's an honest response! There is only one difference in a heat pump that can both heat and cool, and it's a single valve. AC is a heat pump - it pumps heat from inside your car to outside. They all use the Carnot cycle. A heat pump is called that because it can be switched, and can pump heat from outside to inside when appropriate.
Now, exact technical details can matter, and the new heat pump architecture in newer cars is very, very efficiency focused so maybe it's not as good in heat. But it's not because one is AC and one is a heat pump. Like others mentioned, yours sounds broken if it's less efficient.
This is the tire/wheel calibration that was introduced about a month ago in a software update.
I agree it doesn't actually change the energy usage, just the way it calculates it. But wouldn't it stand to reason that at a higher reported consumption, I would show 0% when I still have a fair amount of energy remaining? Or the opposite. At the lower reported consumption, one could run out of power close or at 0%.
MasterC17
Active Member
FWIW, there are quite a few changes from the old design. A liquid cooled condenser, for example, compared to an ambient air exchange system.
Additionally, the system uses a series of valves to change the direction of the process, which weren't needed when it only went in one direction.
So, the system is quite a bit more complex all said and done, but as has been stated, shouldn't result in any additional energy consumption for the cooling process.
Absolutely not. I understand your thinking but it's way off basis.
The power consumption is calculated by measuring the amount of current that passes through the shunt in the penthouse of the high voltage battery (it's not quite that simple but for the purposes of this discussion that's a simple explanation). It's an extremely exact measurement.
Where you can get some variance is in the voltage measurement, since it needs a few hours of rest to get a good measurement, and voltage fluctuates constantly while driving.
But I am 100% certain that changing the wheel/tire combo on the UI is not going to change the reported battery percentage.
Maybe it's like what @MasterC17 said and something is jacked up on it. If so, not worried about it, I have to buy a new one (again) after Jan 1 for tax purposes, so this one is going away anyways.
jackmott
Member
It tries to figure out the diameter of each tire so various things like traction control work properly.
Which is weird, because it definitely reacts to the changing of wheel/tire type also, which impacts diameter. Weird that they would have you set your wheel diameter, and then also allow it to calibrate it, and then also call that "summer" or "winter." I don't think you can even trigger the cal without changing the summer/winter.
One of those cases where you wish they would just come out and tell you directly what it does.
jackmott
Member
So I believe the calibration step is looking for diameter changes that are small from tire wear, different type brands/models etc. I think it is always doing this but if you just got a new set of tires it may speed up how quickly the car figures it out.
The selection of 19/18/winter wheel/tire packages sets the range estimation. Whether it does anything else as well, I don't know!
I am 99% sure it also sets diameter. On the track, I have had all sorts of ABS/TC errors when I set this too far off from the actual tires I have on the car. When it's close, zero issues.
It's odd that the only way Tesla allows you to re-trigger a diameter learn is to change your tires from summer to winter if that is what it does, instead of just a learn trigger button.
DOOLMTR
Member
I’m seeing an average of 323wh/mile with 275/40/18 Advan Apex on 18x10 TE37SL’s. With the OEM 20’s I was at 330 so it’s about the same. At Buttonwillow the average on the day was 660 on sticky tires 
Watts_Up
Well-Known Member
Can you feel a lot of changes in the handling and softness comfort improvement?
Or did you made the change mostly for getting a nicer look?
And it's very sensitive to even modest differences in Rolling diameter. For example the system can tell the difference in Rolling diameter between my 265/30 Pilot Sport fronts and the 275/30 Pilot Sport Rears. This caused Tesla to send me an alert saying that I needed to rotate my tires because my front tires were severely worn relative to the rear ones!
You are just the person I have been looking for haha. I see that you are running 275/30 on the rear tires and I was considering running 275/30 all around but I am wondering why you chose a stagger and what your experience has been with those tires.
The big problem with 275s on the front is that I would have to push the offset way out to clear the front steering knuckle which of course affects your energy consumption and range fairly dramatically- and you're also going to have to run more negative camber to get the tire tucked into the wheel well with those changes. As it is, I've got basically a stock offset on a 9.5 inch wheel and essentially a stock scrub radius at least on the front which is desirable. People who are obsessed with the flush look don't realize that they are changing the scrub radius of the suspension with uncertain effects in terms of how the tire patch behaves at the limit. There's also the question of what the change in scrub radius does to suspension stability in the event of a catastrophic Tire failure or blowout. I don't know myself but I'm pretty confident I don't want to mess with it too much. Somewhat surprisingly the car does not have terminal understeer. Not sure why as conventional wisdom would suggest that it would. It's pretty neutral at the limit if anything seems to have a hint of oversteer. That may be because of the altered scrub radius at the rear where we had to have a higher offset wheel to get the 10.5-in rims inside the wheel well.
Very helpful info but sadly about what I thought and I would prefer not to alter too much for now so it sounds like 275 is probably not a great idea. I looked at 265/30 but they look pretty uncommon, at least through Discount Tire and for convenience sake I guess I'll try out 255 first and see how I like it. Not that it's exactly a "good thing" per say but these cars do seem to eat tires so it's not like I have to live with my selection for 5 years haha
I can recommend highly the 265/30 Pilot Sport on the front even though it is not a Tesla spec tire in other words it does not have the somewhat different tread composition and acoustic foam. I got mine at Tire Rack. Of course like all the Pilot Sport 4S tires especially 30 series they're not cheap and who knows what the supply chain issues are right now with any of these things but the tire itself is great. I can't tell that it's really any noisier than the stock 235/30 Tesla spec which was originally the OEM tire on the car. Unfortunately for reasons that may have to do more with cost and perhaps rolling resistance they went to a Pirelli Pzero Tire on the performance models, which is by comparison a piece of crap. And they also went to that ridiculously heavy 9 in wide wheel which offers really no benefits for handling over the original 8.5 in wheel and is even heavier than the original OEM turbines. We got an enormous Improvement in ride just from swapping out the boat anchors for lightweight forged wheels. Saved an average of 6 lb a corner relative to the 2018 OEM wheels. And those wheels are significantly wider than the stock wheels they replaced so that's 6 lb saved on a much wider rim. The VS14 forged rims combined with the MPP adjustable suspensions literally transformed the cars.
PS and with careful attention to alignment we estimate we're getting about 35,000 mi off of these Pilot Sport 4S tires. Cut that in half if you don't pay attention to your toe and cut it in a third if you are really out of spec on toe
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