OK there is a lot of misinformation about what is going with the 20″ tires with the larger red caliper brakes. For one thing, Tesla has said that you cannot use the 18″ or 19″ wheels with this setup. What are the reasons for this. The folks at Tesla Model 3 Owners Club really explain it well. The net is the stock 20″ wheels got him to 3.2 seconds 0-60 (that’s quite a bit faster than the 3.5 second specification). These are 29 pound wheels mainly because of the extra metal needed.
But with 18″ super light wheels, he got to 3.12. That’s all because with 9 pounds less mass, there is less power required to accelerate. The same is true with bikes, the rotation weight is a big deal around the wheels and that’s also why lighter shoes make a difference too.
It’s a long listen, but watch this and he really explains what is going on. The long and short of it is that the hub on this car is unusual, there is a small lip that keeps standard wheels from fitting and the brakes are so large, you need a special 18″ wheel to fit. The normal Aero wheels do not because the caliper will hit the back of the wheel.
When you get past this, what are the reasons to make a change?
- Winter tires. For winter, you need the opposite of summer tires, Winter tires need to be relatively smaller (18″ is best) and they need to be stiffer so the car does not slide around. Many times, you want a narrower wheel too so that it pushes through the snow. So for this car, you really want a kit that let’s you mount an 18″ rim and then put a nice winter snow tire on it. I’ve been using Tirerack for a while now and they work through these issues, like the need for spacers and so forth. But with the P3D+, it does seem like working with a specialty shop like those folks makes a difference. Note that the compound used for winter tires is different too, so you need to swap for summers when there is no more snow, so they are quite special purpose.
- More efficiency. If you could get the aero covers and an 18″ wheel, then you would have a much lighter wheel at 21 pounds (23 pounds with the aero cover), so it would be faster and with the aero cover, you would get better efficiency. Maybe someone will make an aero cover, super light 18″ wheel for those who want the performance at 3.12 seconds and want the aerodynamic efficiency to to get the additional 10% (that means getting back to 330 miles of the 18″ aeros rather than 280 or so miles than you nominally get with the 20″ wheels. According to the article, the Model X wheels get about half the benefit of being aero without needing a cap, but a plastic cap is going to be much better.
If you look at Tirerack and Tsportline, you can see a set of wheels that will work at 18″ including:
- Tsportline has an 18″ wheel that they claim will fit the P3D+ for $1200 for the rims. It doesn’t have an aero cap, but is 21 pounds.
- Tirerack also has a range of 18″ wheels (non are aero though) that weight 20.9 to 21 pounds and they also claim they fit. The Trimotor C4 seems like it is the lightest of the bunch by a small margin.
As an aside, if you are going to get winter snow tires for a car like this, you probably want the winter performance tires. Tirerack did a nice review and concluded that the Michelin Pilot Alpin AP4 was the best overall by a small margin. The new Pirelli Winter Sottozero 3 and Dunlop SP Winter Sport 4D were just a little bit behind, so not a bad buy if much cheaper.
