Ubertubines to Aeros, if you're talking about the stock tires on each, should be a 10% efficiency bump per Tesla's EPA ratings, and that sounds about right to me.
Just going down to lightweight 18s alone - non-aero, still with performance tires - was probably about a 5% efficiency gain for me. My driving wasn't and isn't consistent enough to put a precise number on it, but I doubt I would've noticed a mere 1-2% gain.
I think there's too much downplaying the impact of wheel size on this forum...
I should clarify for
@tyler879, in case you come back and read more posts here, that I went to 18x8.5" ET35 wheels with 245/45R18 300TW tires. So basically same size and
effective offset (with thinner M3P PUP rotor hats) as base Model 3 aero wheels, except my tires are 10mm wider. (And obviously my tires are "max performance" summer tires, which is a big difference from the efficiency-focused tires that Tesla ships on the 18" aero wheels.)
A lot of times when M3P buyers switch to 18" or 19" wheels they also go wider than stock, often 9.5" wide with 265s or wider. If you're doing autocross or track days or whatnot on the wheels, might as well get that extra grip. Wider wheels/tires obviously present a wider frontal profile, so that should harm efficiency somewhat and could counter any gain from going to 18". Totally fine, nothing wrong with that, just don't complain to me that wide 18s aren't as efficient as I was saying!
I'm guessing - just a guess! - that at constant highway speeds, my 18" wheel efficiency gain is mostly from aerodynamics of taller sidewalls / shorter spokes. My wheels aren't aero at all, but 245/45 sidewalls surely are.
I would guess the weight difference comes into play more for frequent speedup/slowdown driving, like on winding hillside roads. I do a lot of that driving and seemed to gain efficiency there too. (I can't put a precise number on it, I never tried to do a carefully controlled comparison, just it became noticeably easier to match the M3P's EPA rating.)
Again those are just guesses. If I had extra money and time to throw around (I don't) I'd love to run experiments around this. 18" vs 20" comparisons with exactly the same overall weight, to factor that out, and also a same-size comparison with ultra heavy vs ultra light wheels. In both cases using the same tires of course. I'm sure carmakers have done this...