Does anyone have insights into the best "happy medium" tire between performance, comfort and lower rolling resistance?
@SirLaz I think - just a guess, not experience - the new EV-specific tires coming out lately might balance these attributes especially well. Unfortunately sizing and early availability seems to be super limited, e.g. at least one (I forget which) was Model Y sizing only last I checked.
Would something like the Continental PureContact LS perform better than the MXM4s?
I believe those Contis would perform better than the MXM4, we have a similar Conti model (not the LS exactly though) on our S right now and they definitely perform better + feel better dry and wet than the MXM4. However I don't know how the efficiency of the LS would compare. Also the Contis we have on now are *not* Tesla-spec, so no foam liner, and they are noisier than Tesla-spec foam lined MXM4. (How much of the noise difference is due to the foam liner I don't know, mentioning it just in case.)
Btw by "comfort" do you just mean noise level while cruising, or do you specifically want somewhat softer, mushier sidewalls to provide extra smoothness? The best way to balance ride comfort vs performance + feel is to use smaller diameter wheels with good street performance tires. For sure you can also get extra smoothness from a mushier feeling tire but that comes at the expense of dry+wet handling. (An extreme example is how snow tires feel on dry pavement.)
On a Model 3 18" wheels with good max performance tires like Bridgestone Potenza Sport or Michelin Pilot Sport 4S will give you the best balance of performance + ride smoothness. When I switched from my M3P's OE 235/35R20 PZ4 setup to 245/45R18 Potenza Sport I didn't lose *any* steering response at all that I could tell (with 100% stock suspension and bushings - maybe with racecar stiff suspension you could tell more difference). The Potenza Sport sidewalls feel very sturdy compared to MXM4 or similar. For sure many tires would ride even smoother than these Potenza Sports, including the MXM4, but I still gained a lot of smoothness just from the taller sidewalls (plus these also grip much better dry and wet than the OE PZ4, and they squeal less in hard driving). So for me this is a great balance. The only sacrifice is smaller wheels are less stylish.
Now I wouldn't recommend the Potenza Sport for you, it doesn't sound like you have any need for an aggressive performance tire, might as well get something with longer tread life if nothing else. But the basic point is that a good performance-minded tire can still feel good and responsive with taller sidewalls, while riding perfectly fine too thanks to the sidewall height. As you go larger diameter wheels / shorter sidewalls that's when you might feel like you want a squishier, more numb-feeling tire to compensate, and what you'll actually achieve is worse handling + worse ride than having smaller diameter wheels with taller sidewall performance-minded tires.
All that said I think 19" wheels are perfectly fine on this car, as a balance of style and practicality. But if
you feel like your 19" tires still aren't compliant enough, I would suggest going to 18" wheels rather than extra squishy tires.