235/65/18 is almost a perfect replacement for the 235/60R19 tire.

 

So what could be the logic behind "18 won't fit"? I don't have the sport package, which seems to have a different brake system that requires bigger room.

 

Probably the dealer does not sell 18" tires.

 

The brakes on 2023+ RX are bigger than Gen4 RX which could take 18" wheels. Not sure if 18" wheels would interfere with the brakes.

I installed 19" winter rims and tires on my 2024RX which came with 21" wheels.

Additionally the side wall will also be taller if you go 18" and keep the same tire outside diameter. Not sure what it'll do to the handling of the car.

I did down size my 2016 to 18" winters from 20" summers.

 

I used 18" last winter with no issues.

 

There is a Lexus "Tire Rim Calculator" in the toolbar at the top of this page under "Tools". If you put in 18", 40mm offset wheels and 235/65-18 tires against the stock 2023-2024 RX wheel and tire sizes you will see that there is no fitment problem for 18" wheels. You can also click the link below to get to the calculator.

Tire Rim Calculator - ClubLexus - Lexus Forum Discussion

 

For those of you who questioned whether 18 inch wheels would fit on the RX350, see post #54 in the below thread for my recent purchase of the 18 inch RTX Vertex Machine finish wheel and 235/65-18 Defender2 tire package from Tire Rack.

Anyone go with aftermarket wheels on their 5th gen RX350? - Page 4 - ClubLexus - Lexus Forum Discussion

 

Question for you Winter Tire experts. Took my wife's RX 450h+ to Mavis Tire today to swap her factory 21's with our Blizzak's mounted on 18's that are confirmed fit, but ran into an issue with the bolts not working. The aftermarket wheels came with bolts but those don't fit on the Lexus. I assume because these were last on our Toyota Highlander.

Has anyone actually had success with the bolt conversions that were previously mentioned on here? I'd really rather not drop $2K on a new set of tires/rims vs getting the correct bolts that go with these rims (Vision)

 

You would need to clarify a little bit. The actual bolts do not fit? or the bolt pattern does not line-up?
You said that you had bolts that worked on your highlander with those wheels, so it shouldn't be a matter of not having a bolt with the proper seat.
OEM on your 450h is M14 X 1.5. So whatever the winter wheel is (cone or ball) they have to have the proper thread size. This is of course assuming that the winters are 5X114.3 and have a CB (or appropriate adaptor) of 60.1mm

 

What exactly do you mean when you say that the aftermarket bolts don't work/fit on the Lexus? Are the bolts the wrong diameter? Threads don't match? Not long enough? Are you not able to use the original factory bolts with these wheels?

When I purchased aftermarket wheels and tires (19") for winter use, the factory bolts wouldn't precisely center the wheels on the car which lead to vibration at highway speeds. My solution was a different set of bolts that had a more pronounced/steeper "cone" shape at the base of the bolt head that better matched the bolt holes in the aftermarket wheels. The tire shop that I purchased my winter setup from worked with me to find these bolts, which they had in stock. I am not sure if this is your exact problem or not but I hope this helps.

I also got some hub centering rings, so basically now my winter wheel/tire combo's are both hub and lug centered. Now on my second season with no issues.

 

Maybe check with whoever you originally bought them from for your Highlander and ask them if they have a solution for the Lexus.

 

I’ll be the first to admit I couldn’t really understand what they were talking about. The wheels went right on the existing Lexus stems. However, my wheels came with the kit below


those are what don’t fit on the Lexus stems. They told me I’d need something closer to this



so the box says 12x1.5 and I understand Lexus uses 14x1.5, so that’s why I was trying to look up a 14 to 12 conversion.

I have been unable to reach the Discount Tire store I bought from out of state. No idea why they aren’t answering. In the meantime, I figured I’d ask on here.

I also know the factory Lexus nuts won’t fit with the wheels. The holes are too narrow I guess.

ideally, I’d like to just keep reusing this set of wheels and tires, but if finding the correct parts to make it work is not gonna happen, I’ll buy new ones I guess.

 

Highlander has wheel nuts with flat seating surface.

New RX has wheel bolts of different diameter and a cone shaped seating surface.

As far as I know there are no 14mm diameter wheel bolts with flat seating surface from a reputable company that I would trust my family's life with.

There are some no name off shore bolts, but I personally would not risk people's lives for few dollars.

 

is that your gentle way of telling me to go buy a new set from Tire Rack 😂

 

LOL.

This is purely my personal opinion.

I think there were people in NX forum that found ways to use RAV4 wheels on the new NX which is the exact situation as yours.