Hello All,
I always carried a full-size spare in the frunk of my old trusty 2014 RWD Model S. This was still possible in those days before Tesla "shrunk the frunk".
In the Model X, the frunk is too small too so I was looking for another solution. An "emergency spare" instead of a full size wheel.
The MX 5-seaters have this "Trunk under the trunk" space where the 3rd row seats would normally be. It is 20cm in height and large enough to carry an emergency spare. So here is what I did:
1. Buy a steel emergency wheel from a BMW X6 and throw away the tire (wrong size for MX). As the X6 is heavy beast too, it's loading-capacity is good enough for a Model X with all occupants and luggage.
2. Buy a "Continental CST17 155/85R18 115M" which is a emergency-tire with the correct size and load-capacity for a Model X
3. Have my friendly tire guy mount the tire onto the rim. Inflate to 4.2 bar (61 psi) as told to do so by Conti.
4. Have a local shop make a 74.1mm to 64.1mm aluminium centering ring (don't buy plastic). Tesla's have a 64.1 center-bore and the BMW X6 has a 74.1mm center bore (do not make the mistake of using 74.0mm which is more common on BMW's. With a 74.0 to 64.1mm center-ring, the wheel will not center on the hub but "float" instead).
5. Buy a BMX X6 specific, 3mm high-grade aluminium wheel spacers (120x5 with a 74.1mm bore) from a reputable German manufacturer (don't buy crap from China, the car is seriously heavy and powerful so use something strong)
6. Slide the centering ring, which has an inside diameter of 64.1mm, into the 3mm wheel spacer. If both are machined correctly, they fit very snug.
7. Slide the spacer-ring combo into the center "hole" of the wheel. As this is 74.1mm it fits snug because the ring has an outside diameter of 74.1mm
8. Test-fit the wheel, with the spacer-ring combo on it, it should fit snug on the hub and therefore center perfectly and feel solid.
"snug" and "tight fit" are the major keywords. I could not find an emergency wheel strong enough AND which had a center-bore of 64.1
They are all larger and thus will not center on the hub at all and instead, the wheel is held on only by the 5 bolts...
(before anyone starts: I'm not taking anyone seriously that finds that one can mount any wheel, on such a heavy car, easily 3 metric tons with passengers and luggage, which does not center and is literately only held on by 5 puny 14x5 bolts. Despite not being allowed to drive faster than 80kmh / 5mpg, the forces acting on that wheel are enormous regardless)
Back to topic: this particular BMW X6 spare-wheel (I got it from Germany) has an offset that makes it fit onto the front wheel without problems, but it rubs against the rear brake calliper of the newer non-performance Model X'es who have the parking-brake and normal brake integrated. These new callipers are a bit wider e.g. they "stick out" more to the outside. Hence the rubbing with this particular spare-wheel.
This is why I need a 3mm spacer when mounting it onto the rear-axle to clear the calliper.
(the current Performance version of the X has separate callipers for brakes and parking-brake and might not need the spacer but I have no means to test that).
Enough talk. Picture time.
The 3mm spacer (74.1mm inner diameter) with 74.1mm to 64.1mm centering ring slid into it.
The BMW X6 emergency-wheel with Conti Spare-tire mounted.
View from the inside of the wheel.
View from the outside of the wheel.
How the entire wheel fits under the MX 5-seaters "trunk under the trunk" space. The wheel is 19cm high (wide) and that area is 20cm in height. A perfect fit
I put the air-compressor inside the wheel. Why not use that "inner wheel" space for something usefull
I always carried a full-size spare in the frunk of my old trusty 2014 RWD Model S. This was still possible in those days before Tesla "shrunk the frunk".
In the Model X, the frunk is too small too so I was looking for another solution. An "emergency spare" instead of a full size wheel.
The MX 5-seaters have this "Trunk under the trunk" space where the 3rd row seats would normally be. It is 20cm in height and large enough to carry an emergency spare. So here is what I did:
1. Buy a steel emergency wheel from a BMW X6 and throw away the tire (wrong size for MX). As the X6 is heavy beast too, it's loading-capacity is good enough for a Model X with all occupants and luggage.
2. Buy a "Continental CST17 155/85R18 115M" which is a emergency-tire with the correct size and load-capacity for a Model X
3. Have my friendly tire guy mount the tire onto the rim. Inflate to 4.2 bar (61 psi) as told to do so by Conti.
4. Have a local shop make a 74.1mm to 64.1mm aluminium centering ring (don't buy plastic). Tesla's have a 64.1 center-bore and the BMW X6 has a 74.1mm center bore (do not make the mistake of using 74.0mm which is more common on BMW's. With a 74.0 to 64.1mm center-ring, the wheel will not center on the hub but "float" instead).
5. Buy a BMX X6 specific, 3mm high-grade aluminium wheel spacers (120x5 with a 74.1mm bore) from a reputable German manufacturer (don't buy crap from China, the car is seriously heavy and powerful so use something strong)
6. Slide the centering ring, which has an inside diameter of 64.1mm, into the 3mm wheel spacer. If both are machined correctly, they fit very snug.
7. Slide the spacer-ring combo into the center "hole" of the wheel. As this is 74.1mm it fits snug because the ring has an outside diameter of 74.1mm
8. Test-fit the wheel, with the spacer-ring combo on it, it should fit snug on the hub and therefore center perfectly and feel solid.
"snug" and "tight fit" are the major keywords. I could not find an emergency wheel strong enough AND which had a center-bore of 64.1
They are all larger and thus will not center on the hub at all and instead, the wheel is held on only by the 5 bolts...
(before anyone starts: I'm not taking anyone seriously that finds that one can mount any wheel, on such a heavy car, easily 3 metric tons with passengers and luggage, which does not center and is literately only held on by 5 puny 14x5 bolts. Despite not being allowed to drive faster than 80kmh / 5mpg, the forces acting on that wheel are enormous regardless)
Back to topic: this particular BMW X6 spare-wheel (I got it from Germany) has an offset that makes it fit onto the front wheel without problems, but it rubs against the rear brake calliper of the newer non-performance Model X'es who have the parking-brake and normal brake integrated. These new callipers are a bit wider e.g. they "stick out" more to the outside. Hence the rubbing with this particular spare-wheel.
This is why I need a 3mm spacer when mounting it onto the rear-axle to clear the calliper.
(the current Performance version of the X has separate callipers for brakes and parking-brake and might not need the spacer but I have no means to test that).
Enough talk. Picture time.
The 3mm spacer (74.1mm inner diameter) with 74.1mm to 64.1mm centering ring slid into it.
The BMW X6 emergency-wheel with Conti Spare-tire mounted.
View from the inside of the wheel.
View from the outside of the wheel.
How the entire wheel fits under the MX 5-seaters "trunk under the trunk" space. The wheel is 19cm high (wide) and that area is 20cm in height. A perfect fit
I put the air-compressor inside the wheel. Why not use that "inner wheel" space for something usefull
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