18" vs 20" Tires?
08-19-21, 05:19 AM
#151
I have a F sport with 20" and the ride is great, even on relatively roads. However, if I were to live in an area with lots of pot holes, i would be afraid of 20" due to possible Tire and rim damage.
08-19-21, 07:30 AM
#152
Not to worry about that, there's plenty of rubber between the wheel and the road.
08-19-21, 08:39 AM
#153
Personal Preference
Pro's:
Better looking, more sporty look. Larger aluminum area and less black tire
Low profile tires provide better handling during hard cornering
Provides room for larger rotor and caliper on high performance cars
Cons:
Wheels and tires more prone to damage when hitting potholes or scraping curbs
Lower profile tires produce rougher ride. Less sidewall to absorb bumps and generally requires higher PSI.
More expensive to purchase
Tend to be noisier
Heavier "unsprung weight". Given the same circumference, a larger wheel and tire combination will weight more than a smaller wheel and tire. This effects gas mileage.
The following 4 users liked this post by NotAFiat:
08-20-21, 09:01 AM
#154
Driver School Candidate
Hi, I recently purchased 20x8.5 inch TSW Sebring Matte Black (30mm offset) wheels with 255/55R20 Goodyear Eagle Sport All Season tires. Changes the entire look of the SUV. Handle is amazing and ride has not suffered much (even on the horrible streets on Montreal). Kept the thinner OEM 18inch wheels for winter.
08-20-21, 09:16 AM
#155
Driver School Candidate
Here is my opinion on the Pro's and Con's of larger wheels
Pro's:
Better looking, more sporty look. Larger aluminum area and less black tire
Low profile tires provide better handling during hard cornering
Provides room for larger rotor and caliper on high performance cars
Cons:
Wheels and tires more prone to damage when hitting potholes or scraping curbs
Lower profile tires produce rougher ride. Less sidewall to absorb bumps and generally requires higher PSI.
More expensive to purchase
Tend to be noisier
Heavier "unsprung weight". Given the same circumference, a larger wheel and tire combination will weight more than a smaller wheel and tire. This effects gas mileage.
Pro's:
Better looking, more sporty look. Larger aluminum area and less black tire
Low profile tires provide better handling during hard cornering
Provides room for larger rotor and caliper on high performance cars
Cons:
Wheels and tires more prone to damage when hitting potholes or scraping curbs
Lower profile tires produce rougher ride. Less sidewall to absorb bumps and generally requires higher PSI.
More expensive to purchase
Tend to be noisier
Heavier "unsprung weight". Given the same circumference, a larger wheel and tire combination will weight more than a smaller wheel and tire. This effects gas mileage.
Again, it's about tradeoffs. I could have purchased a different SUV, one with a 4 cylinder that got better fuel mileage but I'd rather have the smoothness and quietness of the 6 cylinder - tradeoffs! In addition, beauty is in the eye of the beholder - the larger wheel options looked better on every vehicle I considered purchasing. That isn't saying bigger is always better, there are limits. I haven't seen a car manufacturer go TOO large but some modders go overboard IMO (not a fan of donks).
08-20-21, 10:16 AM
#156
Tire Size Calculator
If you run the two tire sizes through their calculator, it tells us there will be a 3.4% difference in your speedometer readout. The 20" wheel and tire has a larger circumference than the stock 18" setup. This means fewer revolutions per mile hence a lower speedometer number. Make sure you keep the same size tire on each corner otherwise there will be trouble with traction control and ABS.
08-20-21, 10:44 AM
#157
It’s also useful to go to look at the published data for the tire’s revs per mile for each specific manufacturer and “model” of tire. A Goodyear Eagle 235/65-18 tire might be slightly different than another brand 235/65-18 tire. Discount Tire has links to each tire’s spec sheet IIRC. The revs per mile is useful because it factors in the true loaded effective circumference of the tire (remember the tire compresses under load).
08-20-21, 10:56 AM
#158
There are a number of calculators on the internet which will give you great information of different tire sizes. The one I used which is helpful is: https://www.miata.net/garage/tirecalc.html
If you run the two tire sizes through their calculator, it tells us there will be a 3.4% difference in your speedometer readout. The 20" wheel and tire has a larger circumference than the stock 18" setup. This means fewer revolutions per mile hence a lower speedometer number. Make sure you keep the same size tire on each corner otherwise there will be trouble with traction control and ABS.
If you run the two tire sizes through their calculator, it tells us there will be a 3.4% difference in your speedometer readout. The 20" wheel and tire has a larger circumference than the stock 18" setup. This means fewer revolutions per mile hence a lower speedometer number. Make sure you keep the same size tire on each corner otherwise there will be trouble with traction control and ABS.
08-21-21, 10:44 AM
#159
Pole Position
FWIW, the speedometer on my 2020 with stock 20" wheels measures 2 MPH fast (eg. If it says 70, then multiple GPS devices and the other vehicle in the garage will record 68.) I'm not suggesting that the inaccuracy has anything to do with the wheel size. I've heard other anecdotal comments about the same behavior that makes me think Lexus might do it on purpose. It's not a big deal, and I take it into account when setting the cruise speed. BTW, it is a 2 MPH difference, not a percentage difference.
Last edited by TechNut; 08-21-21 at 10:48 AM.
08-21-21, 11:13 AM
#160
Intermediate
Every car I've ever had in recent years, regardless of brand, has come in one or two MPH above actual speed. I've been told that this is an intentional attempt to help drivers avoid speeding tickets.
06-07-22, 06:25 PM
#161
My 2020 RX350 has a rough ride
Hi all-
I'm a first time Lexus owner and have just bought a CPO 2020 RX350 with 49k miles. It's a beautiful car and came with great packages. Unfortunately though, the ride quality is incredibly disappointing. It is very bumpy, and is not very quiet at all. We feel almost every pebble and crack in the road and there is some noticeable road noise. It is a CPO and during our test drive we mentioned the rougher ride to the salesman who said that it seems normal to him. He had some air let out of the tires (down to 33) and we took it on another drive and it improved slightly but was not the buttery smooth, quiet ride that we were originally drawn towards when choosing the RX. Ultimately though, we still bought the car since it was the 2020 refreshed model and had all the specs we wanted and the ride wasn’t horrible, just not the best.
To note, my wife and I test drove about 4 different RXs before making our purchase. We drove two 2017s and I believe a 2018 or 2019 as well. Two of those cars had 18" wheels and two had 20" wheels. We wanted to ensure that the drive remained quiet and smooth even on 20s and it did. We never test drove a 2020 model until going to see this car.
For those who have a 2020 and also had previous years, is there a difference in the ride quality? The earlier model years that we test drove were incredibly smooth even over rough roads and the cabin was so quiet. This is what drew us to the RX in the first place. I was told by my salesman that nothing other than a couple cosmetic or tech upgrades changed with the 2020.
(The tires on the car are Michelin Primacy Tour A/S with 20" super chrome wheels.)
I'm hoping for some input from fellow RX owners as I have no real experience with the car or the Lexus brand. Should I get new tires? Smaller wheels and new tires? Could it be a suspension issue? Did the ride change between model years?
Thanks!
TL/DR - Just bought a 2020 CPO RX350 and the ride is slightly more rough and loud compared to previous model years. Looking for advice/input.
I'm a first time Lexus owner and have just bought a CPO 2020 RX350 with 49k miles. It's a beautiful car and came with great packages. Unfortunately though, the ride quality is incredibly disappointing. It is very bumpy, and is not very quiet at all. We feel almost every pebble and crack in the road and there is some noticeable road noise. It is a CPO and during our test drive we mentioned the rougher ride to the salesman who said that it seems normal to him. He had some air let out of the tires (down to 33) and we took it on another drive and it improved slightly but was not the buttery smooth, quiet ride that we were originally drawn towards when choosing the RX. Ultimately though, we still bought the car since it was the 2020 refreshed model and had all the specs we wanted and the ride wasn’t horrible, just not the best.
To note, my wife and I test drove about 4 different RXs before making our purchase. We drove two 2017s and I believe a 2018 or 2019 as well. Two of those cars had 18" wheels and two had 20" wheels. We wanted to ensure that the drive remained quiet and smooth even on 20s and it did. We never test drove a 2020 model until going to see this car.
For those who have a 2020 and also had previous years, is there a difference in the ride quality? The earlier model years that we test drove were incredibly smooth even over rough roads and the cabin was so quiet. This is what drew us to the RX in the first place. I was told by my salesman that nothing other than a couple cosmetic or tech upgrades changed with the 2020.
(The tires on the car are Michelin Primacy Tour A/S with 20" super chrome wheels.)
I'm hoping for some input from fellow RX owners as I have no real experience with the car or the Lexus brand. Should I get new tires? Smaller wheels and new tires? Could it be a suspension issue? Did the ride change between model years?
Thanks!
TL/DR - Just bought a 2020 CPO RX350 and the ride is slightly more rough and loud compared to previous model years. Looking for advice/input.
Last edited by teatime; 06-07-22 at 07:45 PM.
06-07-22, 06:53 PM
#162
Racer
I'm confused. If you drove other models that were smooth and quiet, why would you then buy the one with a "very rough, loud ride"?
06-07-22, 07:42 PM
#164
We bought this one because we were looking for a newer model in a certain price range with specific packages.
I should clarify that the ride isn’t horribly bad, it’s just not as smooth and quiet as the ones we test drive. I may have been a little dramatic in my post.