As some of you may know, I am not totally on board with Tesla wheels sizes. Model S comes with 19 and 21 inch diameter from factory, and I like ‘em at 20. There is enough “meat” on the tyre to make them able to take potholes better and the tyre sidewall is not too high so it still looks good. I feel the sidewall on the 21s is a little short. Also, in my experience for Model S, the tyre size 245/40R20 is much cheaper than the 245/35R21 or even the 245/45R19. I don’t know why.
So when Model X came to Australian shores, I wanted to look into what can be done. This car comes with 20 and 22 inch diameter wheels, and I think 21 would be a good size.
Model X standard comes with 255mm wide fronts and 275mm wide rears. The Performance comes in 265mm wide fronts and 285mm wide rears. I am relatively confident that 275mm wide will rub on the front’s suspension (but will check anyways). In the US, there is a Winter Package coming in at 265 wide all around, on 19 inch rims (that makes the sidewall very tall, tyre aspect ratio: 265/50R19). So, if you want to put 21 inch rims on your Model X, you can, with the following caveat:
in Australia Model X was not certified with non-staggered wheels.
Let me repeat that. The winter tyres in Australia come in staggered format as well, and in Australia Tesla has not certified its Model X for 265s all around. This might (or not) open you up for issues if you decide on 265s all around and want to rotate your tyres.
Personally I feel rotating tyres is very important. This is because the tyres last longer if rotated. But Model X, at this stage does not have the certification for that. Now, would there be any issue if you’d replace your 255 front/275 rear rubber with 265s all around? To me, it seems this is not a huge issue. I mean, the car is certified in the US with 265s all around. Plus, I feel having 10mm less width on your rear is not really gonna make a huge difference on your grip (impact from tyre compound and wear is far higher imho).
Would I recommend you to change them? Definitely not unless you confirm with your insurer. It is expected that going wider on the front is going to work in your favour, the issue could be a smaller width in the rear.
So, that being said, you could change the wheels for 21s, with the following specifications:
Front: 21 inch diameter, 8.5 to 9.0 inch wide, Offset +25 to +35
Rear: 21 inch diameter, 9.5 to 10.0 inch wide, offset +25 to +40
All around: PCD 5 x 120, Center Bore 64.1mm.
Load Rating: While factory load rating is lower on the front than rear, I highly recommend going to a load rating of 900+ kgs all around. Even Model X 75D is a 2.5ton+ car when empty, and it is capable of towing 2tones +. I would definitely not skimp on the wheels of such a heavy car.
Special Note: You CANNOT use Model S 21 inch rims for a Model X. Why, I hear you say? Well one reason is that usually (afaik) Model S 21 inch rims are not staggered, but MOST importantly, the Model S rims have a LOWER weight rating than Model X. This means if you use Model S rims on your Model X, the rim will not be capable to take the weight and you might have a boo-boo (read collapsed wheel not covered by insurance).
So, to recap:
You can go to 21 inch wheels but (unless insurance agrees) you must have them staggered (can’t rotate tyres) and they must have the appropriate rating.