255/45/19 Y tires are 6.4% taller than the 3's 235/40/19. Both vehicles have a final drive ratio of 9:1, so the tire size is giving the Y taller gearing which should help efficiency but hurt acceleration. City should be worse and highway improve. There have been other threads where people shout that gear ratios don't matter at all. Obviously they do, and Tesla found 9:1 with these tire sizes to be the best performance/efficiency trade-off. Also, older Model S/X had a 4% taller front motor gearing for it to take over on highway "range mode". If taller gearing doesn't give more range, then why make it different from the rear? That has now changed since the S/X use permanent magnet motors that never shut off. All of this to say that I believe the additional gearing helps range despite the 500# extra and greater front surface area affecting aerodynamics. Unfortunately, it looks like the tire size is just a bit too big to fit onto the 3 due to the knuckle. Otherwise I'd test the 3 with taller Y tires.
