RX330inFL

Didn't think I jumped to that conclusion. The question asked that I answered was whether they would see a difference in winter between 18" or 19" wheels. My answer was no, not really. The only difference would be seen with narrower tires and provided a URL from Tire Rack to back that assumption. How they get there is another matter. The 18" wheel would be better for attaching chains due to the larger sidewall on the tire.

Do not let the fact that I am in FL fool you. I have been in many a winter condition tough for even a Snowcat. My favorite winter vehicle was an old Subaru 4x4 wagon. Had all-terrain tires installed for on and off-road use which was especially helpful during hunting seasons. Never left me stranded even in the worst winter conditions.

While the tire sizes in question, 235/60-18 and 235/55-19, technically have the same width. However, there are differences between tires of these sizes which will affect the actual tire contact patch on the pavement -- some narrower than others. Additional air pressure will also affect the amount of tread touching the pavement on many tires. One reason not to crank up the air pressure in your tires as it affects stopping distances due to the lower tire contact patch.

GoGiantsNJ

I have the19's on my 2012 RX. I did have the Dealer switch out the terrible Dunlops to Michelins when I bought the RX new.. The Michelins are far superior to the Dunlops.

elba123

Does the vehicle ride higher on 19" tires compared to 18"?

Or is tire diameter the same for 18" and 19" although the wheel inside the tires has 19" diameter in one case versus 18" in the other?

cavedawg

elba123

Depends on sizes. If I got this right, the first set of numbers is the sectional width in mm (or distance from sidewall edge to sidewall edge in millimeters when measured up and over the tire's tread), the second set is the Aspect Ratio (its section height compared to its section width) and the third is the rim diameter. A 255 sectional width is wider than a 235 and a 60 sidewall will be greater than a 50 (60% of sectional width versus 50%) and of course a 19 is bigger than an 18. Go to
www.tirerack.com and find the brand and type tire you want. You can also search by vehicle if you choose. If you look at the page of the brand and type (model) you want (I used Michelin Latitude Tour HP), there is a group of tabs toward the bottom of the page. Click the tab that says "specs" and look under the "outside diameter" column for the size tire you want (saves you doing the math). Even if the outside diameter is 1" larger the car will only ride a half inch higher. The chart tells me a 235/55R19 is 29.2" outside diameter and a 235/60R18 is 29.1" outside diameter. So yes, in this case your car would ride higher on the 19" versus 18" by .05" if that would matter to you. So, as you can see, there are variables at play in tire sizes.

C

zmanRX350

I have 19" 's installed by dealer. I can't wait till factory Dunlops wear out to put new Yokohama's on mine. The factory Dunlop's are terrible.

Dolphin

I had the factory 13RX F Sport 19" rims with Mich. Duellers, as well as modified suspension, installed the Damper from the F Sport model. (see other threads regarding this) Overall, body roll was greatly reduced over 18" rims and factory suspension, which I was always reminded of when I got a loaner.

then, I replaced the 19" with 20" rims, and now have a 1" wider contact patch on the road, used Mich. HP vs. the previous Duellers. I expected better cornering with the 20".... the opposite happened, the HP's sidewalls are NOT as stiff as the Duellers, the cornering performance lessened, ride is slightly more plush. If I could do it over, I would have put 20" Duellers on, live n learn. The 1" wider footprint prob. will offer better traction, but I do not notice any other benefits, except the wheels look a little nicer not hidden inside the wheel wells as far, but its a small amount, but yet, noticeable.

papitorok

Great info. Thanks.

KKoll

Just purchased a 2016 CPO with 19" rims. I would have preferred 18s for the softer ride. I think the whole low profile/sporty concept is overblown and makes no sense on a car like a RX. I also have a Miata and I actually changed to higher profile (50 vs 45) on that car since the backroads around here are pretty beat-up. That said, the RX with 19" rides great and the whole setup feels better / more responsive than our 2006 (new shocks probably have a lot to do with that result).

ronmaiden

I prefer a little more sidewall since it also provides a little more margin or error when hitting a pothole or such there's more rubber between the wheel and the pavement.