I want to buy a new RX350 with navigation and 18" wheels. However, in all of southern CA there is no such combination. Navigation comes with 19" wheels. Has anyone compared the ride quality between the two? I want a very smooth ride, but everything I read says that 19" wheels make the ride harsher.

 

Best to drive one with 19s. I have the 18s and recently had a loaner with 19s. I didn't honestly notice much of a difference.

 

Welcome to CL skirk51. If you search this forum, you'll find many comments about the ride quality. One thing to note is some members have found it has improved over earlier model years. Tires can make a big difference. We have a thread devoted to that. Of all OE brands, preference is Michelin, Bridgestone and Dunlop in that order. And try to drive both like JDR said. Maybe they have a 2013+ on the lot with 18"s. This is one of those subjective topics. I wouldn't rely on opinions alone. Good luck.

 

Also if you drive both 18 and 19's,make sure the tires have the correct air pressure listed on a label at the driver's door jamb area..
Dealers usually have too much air in tires which causes a harsher ride.

 

I have an f sport with 19s and the ride was quite harsh. I ditched the v rated tires for h's with a higher sidewall (245/55r19s) and it made a ton of difference. But I just had a loaner with the combo you want so it's curious that a dealer can't find one. The ride was great in it. If you can't find one with 18s ask the dealer to swap them out or just purchase 18s after you take delivery and sell the 19s. People are always looking for OEM 19s. You'll probably make a profit too.

 

Can't you just test drive a non-nav with 18s and a model with 19s back to back and see for yourself? My wife has a CX-9 with 20s, which rides waaaaay better than our previous Pilot with 16s.