Gen 2 NX does not come with 17" tires from factory in any trim.

I would stick to an OEM size. Smallest oem is 18".

Going from 20 to 18" should impressive the ride comfort. Handling will be sacrificed a bit though.

I tried to find an SUV that will be closest in ride quality to ES350 but smaller than RX, per wife's request. Had to be a hybrid also. Turns out I absolutely hate NX ride dynamics, likely due to 20in runflats. RX had sideroll which I didn't like but tolerated a lot better.

Now NX has almost 30k miles on it and we have to decide on next tires or car. Wife is willing to switch to a car or minivan. Lexus dealer said it will cost me about 17k to switch to 2024 luxury ES300h. Those unfortunately come with 19in tires and Toyota safetysense 2.5, so will be downgrade from 3.0 safety system that NX has and will lose the UL, including ML audio.

Having had the 2020 ES300h, NX350h and RX350h my experience has been the smoothest is ES. RX is next and the NX last.

I am sure the NX with 18" wheels will be softer.

Also, a set of normal Michelin Cross climate 2 tires might help the NX350h ride quality.

For me the ES was too floaty and rode like the 70s Cadillac. RX is smooth, but not a lazy boy on wheels. Perfect balance for me.

Typically motion sickness comes from side to side movements. NX with 20" has rougher ride, but shouldn't be bouncy.

Where do I get OEM 18in rims or tire shop will just order them?

They won't be cheap.

If it were my money, I would do an extended test drive of a NX 350h with 18" tires back to back to your current car before deciding on spending few thousand dollars.

If 18s meet your requirements you can find nicer aftermarket rims than original 18s.

I recall someone getting 18” OEM wheels for about $256 apiece. While the brakes are a mix of some midsize stuff, the rav4 (lower trim toyota, same platform, but may have slightly smaller brakes) does come with 17”, so a fitment check would be required. By the end of tomorrow, I will have the Michelin CC2 on, so I’ll report back later if they are softer than my OEM runflat 18”s.

Lexus Canada has a nice accessory 18" wheel for NX (at least to my taste).
If you are close to Canada you can get that and with current exchange rate that will be almost peanuts in US$ 😀😀

I may just bite the bullet and get the ES. Anyone can comment on V6 vs hybrid in terms of smoothness/motion sickness?

The V6 ES is probably a very smooth and powerful sedan. We had one in the past. Never drove the Hybrid to comment there. ES V6 maybe going aways after 2025. The last of the reliable V6 before it's turbo engines or hybrid 4 cylinders probably.

If your NX is a hybrid, get a Hybrid. If you have the turbo NX, get the V6

Costco does have Michelin Defender 18in tires and a selection of 18in wheels.

Wheels are on sale, $150 per piece. Will go ahead with this, not sure what size 18 in rims I should be ordering, there are several.

Is $150 the price for 235/60/18?

That is what is the factory 18"s

its 225/60R18 when I select NX year 2022 on https://veloxwheel.com that Costco uses. When I select NX as year 2023 says recommended tire is 235/60R18. Same wheel with matching part number and costco item number. Looks like should be OK for my NX?
18by x8 +40 offset 5 by 1 1 4 . 3 5-114.3
Velox PN# SFAP183076
Costco Item# 1407654

Every tire that costco website selected for my NX is 235/60R18.

I have stock 18s and looking to trade up for 20s. Too bad you’re not in Chicagoland.

Will you be planning to go anywhere else soonish?