The 2019 Lexus Trucks RX350 blends luxury-crossover comfort with the polished road manners that made the RX a long-running staple in the premium SUV market. Buyers looking at this exact model usually are not sorting through vintage sizing systems, but they still need to confirm the right wheel and tire package before replacing anything. This RX350 uses modern radial tire sizes, with 235/65R18 and 235/55R20 both appearing across the model range. That makes the real decision less about old-versus-new construction and more about matching the correct size to the vehicle’s wheel setup, trim, and intended appearance. Verifying whether the vehicle is a Base or F Sport is the right place to start.
Which Tire Size Is Right for The 2019 Lexus Trucks RX350
The 2019 Lexus Trucks RX350 uses two primary tire sizes, and the right one depends on the exact sub-model and wheel package. Both are radial tires, but they mount on different rim diameters: 18-inch wheels for 235/65R18 and 20-inch wheels for 235/55R20. Before choosing a replacement, confirm the vehicle’s sub-model and actual wheel diameter so the tire size matches the setup already on the RX350.
235/55R20 is a metric radial size in which 235 identifies the nominal section width in millimeters, 55 is the aspect ratio, R denotes radial construction, and 20 is the wheel diameter in inches. On the 2019 Lexus Trucks RX350, this size is part of the modern low-profile crossover fitment story and is tied to a 20-inch wheel. Its lower-profile format gives buyers a different visual and fitment context than the 18-inch option. This is the size to evaluate when the RX350 is equipped with 20-inch wheels, including the F Sport configuration.
235/65R18 is also a metric radial size, with 235 representing nominal section width in millimeters, 65 indicating the aspect ratio, R for radial construction, and 18 for the rim diameter in inches. For the 2019 Lexus Trucks RX350, this size belongs to the 18-inch wheel setup rather than the 20-inch package. Compared with the 20-inch fitment, the key difference for the buyer is not construction but wheel diameter and the tire’s profile family. This size should be chosen only after confirming that the vehicle is running the 18-inch wheel arrangement.
Tire fitment on the 2019 Lexus Trucks RX350 is not the same across every sub-model. Checking whether the vehicle is a Base or F Sport matters because the available tire sizes and wheel diameters differ, and that changes which replacement size belongs on the vehicle.
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2019 Lexus Trucks RX350 Base
The 2019 Lexus Trucks RX350 Base can appear with either of the two primary radial tire sizes, depending on its wheel package. That means tire selection starts with confirming whether the vehicle has 18-inch or 20-inch wheels before comparing replacement choices.
The 2019 Lexus Trucks RX350 F Sport uses the 235/55R20 radial size rather than the 18-inch fitment. For replacement planning, that keeps the decision focused on maintaining the correct 20-inch tire size and confirming the wheel setup has not been changed.
The tire sizes listed on this page assume factory-standard vehicle configuration. The following modifications may affect tire fitment and are not reflected in this guide:
Suspension changes (lowering, lift kits, spring replacements)
Body alterations (fender modifications, custom bodywork)
If your vehicle has been modified from factory specifications, verify tire clearance before purchase.
Frequently Asked Questions
These FAQs focus on the tire sizes used on the 2019 Lexus Trucks RX350, how fitment changes by sub-model, and what to verify around wheel diameter, replacement selection, and road-use readiness.
Tire Size & Fitment
What tire size fits a 2019 Lexus Trucks RX350?
The 2019 Lexus Trucks RX350 uses either 235/55R20 or 235/65R18, both in radial construction. The correct size depends on the vehicle’s sub-model and wheel package, with the F Sport using 235/55R20 while the Base model can appear with either size depending on how it is equipped.
The most important step is confirming the actual wheel diameter on the vehicle before ordering tires. An 18-inch tire and a 20-inch tire are not interchangeable, even though the overall tire dimensions are relatively close, so the wheel itself needs to match the selected tire size.
What size rim does a 2019 Lexus Trucks RX350 use?
A 2019 Lexus Trucks RX350 uses either an 18-inch or 20-inch rim, depending on the tire size fitted to the vehicle. The 235/65R18 size mounts on an 18-inch wheel, while the 235/55R20 size mounts on a 20-inch wheel.
Checking the wheel diameter is the quickest way to narrow down the correct tire size on this RX350. Looking at the sidewall of the current tire, verifying the wheel markings, and confirming whether the vehicle is a Base or F Sport can prevent buying a tire that matches the brand or tread preference but not the wheel.
Do all 2019 Lexus Trucks RX350 sub-models use the same tire size?
No, the 2019 Lexus Trucks RX350 does not use one universal tire size across every covered sub-model. The Base model can use either 235/65R18 or 235/55R20, while the F Sport uses 235/55R20.
That difference means the trim badge alone is helpful, but the wheel diameter still deserves a quick check before replacement. Base models can be equipped more than one way, so matching the new tire to the actual wheel on the vehicle is more reliable than assuming every RX350 uses the same size.
Choosing the Right Tire
What should I consider when choosing a tire for a 2019 Lexus Trucks RX350?
Start with the correct tire size for the vehicle’s wheel package: 235/65R18 for the 18-inch setup or 235/55R20 for the 20-inch setup. Because both fitments are radial, the main selection factors are size accuracy, wheel diameter, and making sure the replacement matches the configuration already on the RX350.
After that, compare the vehicle’s intended use and existing setup. A daily-driven RX350 with original wheels calls for a straightforward size match, while one with aftermarket wheels or prior suspension changes should be checked for clearance, wheel width, and overall compatibility before settling on a replacement.
How do I choose between the available 2019 Lexus Trucks RX350 tire sizes?
The two sizes are not alternatives to choose between casually; they correspond to different wheel diameters on the 2019 Lexus Trucks RX350. A vehicle with 18-inch wheels needs 235/65R18, and a vehicle with 20-inch wheels needs 235/55R20.
The practical decision is really about identifying the wheel package already on the vehicle. Once that is confirmed, the correct size follows naturally, and the rest of the comparison can focus on factors such as ride goals, road use, and whether the RX350 remains on its original wheels or has been modified.
How do I choose between the available 235/55R20 and 235/65R18 tires for a 2019 Lexus Trucks RX350?
Choose between 235/55R20 and 235/65R18 by matching the tire to the wheel diameter already on the 2019 Lexus Trucks RX350. The 235/55R20 size belongs to a 20-inch wheel setup, while 235/65R18 belongs to an 18-inch wheel setup, so the wheel determines the tire rather than personal preference alone.
The current vehicle configuration matters more than comparing the two sizes on paper. A Base model may use either setup, and an F Sport uses the 20-inch size, so checking the wheel and reading the existing tire sidewall is the safest way to avoid ordering the wrong fitment.
Restoration & Appearance
Does correct tire fitment matter for a 2019 Lexus Trucks RX350 restoration?
Yes, correct tire fitment still matters on a 2019 Lexus Trucks RX350 even though it is a modern luxury crossover rather than a vintage restoration project. Using the proper size preserves the intended relationship between the tire, the wheel diameter, and the vehicle’s stance.
Appearance on a later-model vehicle is often tied to keeping the proper wheel package in place. An RX350 wearing 18-inch wheels should stay with 235/65R18, while a 20-inch setup should stay with 235/55R20 unless a broader wheel-and-tire change is being planned and measured carefully.
How does tire size affect the appearance of a 2019 Lexus Trucks RX350?
Tire size affects the visual balance of the 2019 Lexus Trucks RX350 because the two fitments use different wheel diameters and sidewall proportions. The 235/55R20 setup presents a larger wheel with a shorter sidewall, while 235/65R18 pairs with an 18-inch wheel and a taller sidewall profile.
That difference is one reason it helps to keep replacement tires matched to the vehicle’s existing wheel package. Changing only the tire without considering the wheel can upset the intended look, and changing both should involve careful checks of clearance, suspension condition, and the overall package on the vehicle.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 2019 Lexus Trucks RX350?
Yes, modifications can affect tire fitment on a 2019 Lexus Trucks RX350. Wheel changes, altered offsets, suspension lowering, or body modifications can change how much room the tire has at the fender, suspension, and steering points, even when the tire size itself appears correct.
A modified RX350 should be checked as an actual vehicle rather than treated like a stock one. Measuring the current wheel diameter and width, looking for rubbing marks, and checking clearance at full steering lock can help confirm whether the intended replacement tire still suits the vehicle’s present setup.
What should I inspect before driving a 2019 Lexus Trucks RX350 on new tires?
Before driving a 2019 Lexus Trucks RX350 on new tires, inspect the wheel size, confirm the replacement tire size matches the wheel, and make sure inflation is set appropriately for the vehicle and tire. It also helps to check for any visible clearance concerns around the fenders, struts, and steering components.
A short follow-up inspection after the first drive is also worthwhile. Looking for uneven seating, unusual vibration, or contact marks can catch issues early, especially if the RX350 has aftermarket wheels or has gone a long time since its last alignment, suspension service, or tire replacement.
What should I check before a longer drive in a 2019 Lexus Trucks RX350?
Before a longer drive, confirm that the 2019 Lexus Trucks RX350 is on the correct tire size for its wheel package and inspect each tire for proper inflation, tread condition, cuts, bulges, and visible sidewall damage. A quick walkaround can also reveal uneven wear or a tire that appears low on air.
Longer trips put more importance on basic condition checks, especially on a vehicle that may have sat for stretches between uses. Looking at tire age, checking for vibration on the first few miles, and making sure the wheels and suspension feel normal can help avoid preventable road-use problems.
