Range calculation switching from 20s to 22s and back

[DanLA]

Hi all,

Just received my Raven Model X that I purchased with the 20s. I got a set of the OEM 22s. My plan is to primarily use the 22s but switch to the 20s for road trips. At purchase, I was told the only way to get the computer to know the wheels have changed is to either have mobile service come out and swap the tires or bring it in to get the computer reset to calculate based on the 22s.

My goal is to swap the tires myself whenever I need to. But I really don't want to have to go in to get the calculator changed. Worst case is I leave the X thinking it has 22s on when I go back to the 20s and just have a more conservative supercharger planning.

Can anyone confirm is this is correct or if there's a way to remotely or independently tell the computer which OEM size you are running?

 

[Akikiki]

You can check this yourself. While the wheels are different in sizes and the inside diameter of the tires is different, the overall outside diameter of the tires (mounted so fully inflated) are the same for 20" and 22". Don't forget the X can come with 20" or 22". The computer does not need to be adjusted. Measure the outside diameter and/or the radius to confirm. The car doesn't care but your picture in the dash is not going to change just because you switched wheels and tires.

To help put this in perspective, the S comes with 19" and 21"s. And the outside diameter of each of those two are the same. The computer does not need to be adjusted.

I think your goal is to switch wheels and tires, not just tires. Right?

 

[SSedan]

Very good explanation if the OP was worried about the speedometer.........

Seems the OP is more concerned with the efficiency difference with the tires on the 22" being less efficient, impacting range calculation. To that concern the car constantly recalculates destination charge remaining based on actual use so if you put on more efficient setup it might calculate 10% at destination but then as you drive will rebalance itself and you would see that percentage climb.

The plan to have the factory set it for 22" and leave it is sound.

 

[DanLA]

I think your goal is to switch wheels and tires, not just tires. Right?

Yes. I'd like to be able to change between the two sets whenever I want and have the range calculate correctly. The EPA rating on the 20s is 305 miles and 270 miles for the 22s. I'm making an assumption that when the computer calculates range-to-empty it factors in the difference if the car is on the 22s. Maybe that's an incorrect assumption but I kinda doubt it.

So basically, if I were to calculate out a long distance drive I'd ideally like the car to "know" which wheels are on it so it spaces out the SC visits properly.

 

[DanLA]

The plan to have the factory set it for 22" and leave it is sound.

Makes sense. So basically I can just change out these myself and then make a visit to get them to update the computer for the 22s.

 

[mswlogo]

On Model 3, you can "Reset" TPMS and when it Prompts it asks for wheel size. Not sure X does that.
It also would sense the TPMS change and also Prompt for Wheel Size.

This is important for me, because I was thinking of getting the 19" Snow package.

I agree, technically the rolling distance is the same on all OEM Wheels on the 3, but it still wants to know which wheel. If it was for efficiency calculation, I could care less. You're driving habits will be more influence.

It might be tuned for which wheel for Electronic Stability Control and/or Towing.

 

[SSedan]

I believe it prompts so it knows what pressure to expect.

 

[mswlogo]

I believe it prompts so it knows what pressure to expect.

It might know how the tire might handle at different pressures for different wheels.
But that's pretty much what I said, the Stability Control might have many parameters on how the different wheels (tires) behave (including how they might behave at different pressures)

Cold PSI is the same for all Model 3 OEM Wheels. The rise is probably similar as tires heat up.

If the Cold PSI recommendation is different for each Wheel on the X, yeah it probably has a different warning range.

 

[SSedan]

On the S pressures vary with rim size so it sets different alarm limits.

On the 3 even if the cold pressures are the same I would if it would have different low pressure alarm settings, narrower window of operation for the larger rims????? Pure speculation.
Heck it might be just changing the dash pic to make people feel like it does something. You know that is it didn't offer the rim size choice and the S X do they would field a ton of questions.

 

[mswlogo]

On the S pressures vary with rim size so it sets different alarm limits.

On the 3 even if the cold pressures are the same I would if it would have different low pressure alarm settings, narrower window of operation for the larger rims????? Pure speculation.
Heck it might be just changing the dash pic to make people feel like it does something. You know that is it didn't offer the rim size choice and the S X do they would field a ton of questions.

My Dash Picture does not change when I put 19" ;(

But yeah, narrower range for large rims could be true. Could be for future as well as consistency across other models that do have different pressures. It does not hurt for software to know.

 

[Macgaver]

Good news for you, in the version 2019.32.1, they are adding a new menu section to switch the tire size by yourself

You can see it in action here:

 

[BigMskiman]

Good news for you, in the version 2019.32.1, they are adding a new menu section to switch the tire size by yourself

You can see it in action here:

Yes, as @Macgaver says, it's your lucky day!

old |v2019.28.3.1|AP2,MCU1,PUP|
new |v2019.32.1|AP2,MCU1,PUP|