Model Y winter tire test 225/60R18 vs 255/45R19 vs 255/55R18 braking, acceleration, consumption

First test is done, lot learned what not to do and how to do a bigger test like this with many different tires during the same day.
If you want to make good testing basics need to taken into account.
I waited two weeks so weather would be optimal for the tests. That means:
- no wind we had only 1m/s (under 3m/s is ok for our forest route)
- Constant temperatures, we had it within 1c change
- No new snow
Well here we got the first two correct, but we cannot control the plowing of the big roads as you cannot even go plow it more, even if you have the equipment.
There was little bit of fresh snow on the road since last plowing and before that had came a lot which all were not packed and they did not get everything clean which is the case in most cases on smaller roads like this. This snow started to pack during the day on each car drive by. Impact were pretty identical for the consumption 10,9% and braking 10,7% and even more for accelerations 14%.
We also had empty battery problems and had to go to the main city fast charger to get more power. So when testing make sure you have fast charger where you change tires/parts. We had a 1.5 hour delay due to that and darkness arrived.
Next tests will be done at dry tarmac roads near the charger. Propably during night as otherwise the traffic will make testing more difficult. Then hopefully those other 2 tire sizes can be tested as well as I am not yet happy for 8,5% savings. Sadly I cannot afford to buy a 195/60R18 size winter tires which would be aerodynanamically best. I assume the 215 will get energy saving over 10% with correct offset and wheel widths easily.
Special thanks to people who has helped to get these wheels and tires: Some of the wheels and tires have been travelling here from Germany.
R8 1:1 team Mikko Ahola and Sami Sivonen
Petri Ivakko
Kari Tiittanen
Ville-Markus Pykäläinen
Tomi Jääskeläinen
Tuomo Niittylahti
Toni Mikkonen
Kari Pölönen
Arto Tanskanen
Still searching for some wheel sizes...
Huge thanks to my own Family members, who also made this possible.
Now back to garage to prepare parts for the next tests.

[@Bratfalken]

Some questions: what speedometer did you use, an gps or a mechanic/electric that the car has? I mean as tire size differs, it would affect the later one. Have an periferal calculation of the length of the tire circumference, diameter of the rim plus twice the height of the width times the profile and all times Pi. Making an example look like this in a formula =((18*25,4)+(2*(255*0.45))*PI()) this will give you the circumreference of a tire in mm. Good job in though conditions, I take it the Hakka R5 is the newest non studded tire? I just bought studded Hakka 10 SUV 235 65 16" for my Volvo XC 90 and they are great... but expensive, but safety has no price, the ones that the car had where "air matresses" Good luck!

[@TunekoLtd]

First we check diameters with willtheyfit.com. Here remember winter tires have 8-9mm thread when new. Those 225/60r18 are 2.08% bigger and those 255/55r18 are 3.47% but they are more worn so diameter/speedo error was same between these 2 other sizes.
So we use GPS speeds and then take error into account in the consumptions as tesla does not correct their meters based on tire size. Distance is fixed for consumption.

[@TunekoLtd]

Hakka =hakkapeliitta shortened In finnish and Yes the R5 is latest generation of it from Nokian tyres. Ev version has a foam inside, just like the model y hankook 255/45r19 tires have from factory.

[@Bratfalken]

@@TunekoLtd as a Swede I would be prone to miss spell the whole name, so I use the shorter one. Also, I allways miss when it is Nokia or Nokian! ;)