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Wheel Weight: 19" vs 21"

When my MS is delivered at the end of Feb, I want to change the wheels (rims) and tires to 20". Seems like I could sell my 19" tires and rims.

I volkerized tire weight, but couldn't find a thread that posted the exact weight of the 19" and 21" rims. Does anyone have that info? I want to make sure the 20" rims I order are about the same weight as 19" and aren't heavier than the 21" rims.
Thanks.

northern-va-dave | 2 février 2014

Assuming the wheels (rims) are made of the same material, and have approximately the same pattern/style but are just changed in diameter and width, of course the 19" wheels (rims) will weigh less than the 20", which will in turn weigh less than the 21". (Excluding the tires mounted on those wheels.)

Assuming a solid cylinder, the weight = (pi)(R^2)(H)(D), where R is the wheel radius, H is the height (or wheel width depending on your perspective), and D is the density of the material. All other things being equal, if you increase the diameter of your wheels, you will increase the weight (i.e., your 21" wheels will contain more net aluminum than your 19" wheels). And, considering that a larger diameter wheel most likely has a larger width as well, you will also increase the weight.

According to "http://www.teslamotorsclub.com/showwiki.php?title=Model+S+-+FAQ":
Quote:
--
"Width:
19x8 for 19" wheels
21x8.5 for 21" wheels

Weights:
19" Wheels: 13.74kg ~30lbs each (according to a Tesla engineer)
19" All Season Tires: 27lbs each (according to Tire Rack for Eagle RS-A2 245/45 19")

21" Wheels: 35lbs
21" Continental ExtremeContact DW Tires: 26lbs"
--

Now, if the style or pattern of your wheels (rims) is different between the 19", 20", 21", such that, say, hypothetically the 20" wheels use net less aluminum than the 19" (e.g., less or thinner spokes, larger vents, etc.), then perhaps it would be possible that the 20" wheels could weigh less than the 19". But I have a hunch this would be really unlikely on the stock Tesla configured wheels.

The tires are another story, however, because you are actually decreasing the sidewall height more than you are offsetting by increased width, and you may have thickness, density, etc. variations as well. (Note above that the 21" conti's weigh a pound less than the 19" all-season. Putting aside the fact that they are different brands, etc.)

Volkerize also provides the following for "wheel weight":

http://www.teslamotors.com/forum/forums/correct-model-s-rim-weights-and-...

http://www.teslamotors.com/forum/forums/check-out-my-new-wheels