The 2018 Buick LaCrosse sits in the final generation of Buick’s full-size sedan, blending a quiet, upscale road manner with modern wheel-and-tire packages that vary by trim. That matters here, because tire selection for this car starts with confirming the exact sub-model and wheel diameter rather than assuming every LaCrosse uses the same setup. Depending on trim, the 2018 Buick LaCrosse uses 235/50R18, 245/45R19, or 245/40R20 radial tires. Available choices also vary in character, from straightforward blackwall performance radials to redline and raised white letter options in select sizes. The right pick comes down to matching the trim, the wheel, and the look you want from the car.
Which Tire Size Is Right for The 2018 Buick LaCrosse
The 2018 Buick LaCrosse uses three primary tire sizes, and the correct one depends on the exact sub-model and wheel diameter. All three are modern radial sizes, but they are matched to different 18-inch, 19-inch, or 20-inch wheel setups. Before choosing a tire, confirm the trim level and the actual wheel currently on the car, especially if it has been changed from stock.
245/40R20 is a modern metric radial size where 245 is the section width in millimeters, 40 is the aspect ratio, R identifies radial construction, and 20 is the wheel diameter in inches. On the 2018 Buick LaCrosse, this size supports trims equipped with a 20-inch wheel package and gives the car its most aggressive original fitment profile. Product choices include BFGoodrich, Nitto, and Pro-Trac options, with blackwall, redline, and raised white letter sidewall treatments available. This size is the one to evaluate when the car has 20-inch wheels and appearance is part of the decision along with fitment.
245/45R19 follows the same modern metric radial convention, with a 245-millimeter section width, a 45-series profile, radial construction, and a 19-inch rim. On the 2018 Buick LaCrosse, this size appears on specific Avenir applications and centers the decision on confirming that the car actually has the 19-inch wheel setup. Available tires in this size come from BFGoodrich and Nitto, primarily in blackwall form across several performance-oriented radial series. This is the right size to pursue when the wheel diameter is 19 inches and you want to stay with the proper original fitment format for that configuration.
235/50R18 is a modern metric radial size in which 235 gives the width in millimeters, 50 is the aspect ratio, R means radial, and 18 is the rim diameter in inches. For the 2018 Buick LaCrosse, this size serves several trims using 18-inch wheels and is the most broadly shared fitment in the range. BFGoodrich, Nitto, and Pro-Trac all offer choices here, with blackwall, redline, and raised white letter variations depending on the tire series. This size is the practical starting point when the car has 18-inch wheels and you want to compare both conventional and appearance-focused tire options.
Tire fitment on the 2018 Buick LaCrosse is not the same across every sub-model, so identifying the trim is the first step before choosing a replacement. Some trims share the 18-inch setup, while others can use larger wheel-and-tire packages that change the required size.
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2018 Buick LaCrosse Avenir
The 2018 Buick LaCrosse Avenir uses either a 245/45R19 or 245/40R20 radial tire, making wheel confirmation especially important on this trim. Tire selection starts by checking whether the car is on its 19-inch or 20-inch setup, then comparing available blackwall or appearance-oriented options within that size.
The 2018 Buick LaCrosse Base uses the 235/50R18 radial size. That keeps replacement straightforward as long as the car still has its 18-inch wheels, after which the choice becomes comparing tire series, sidewall style, and rim-width compatibility among the available products.
The 2018 Buick LaCrosse Essence can use either 235/50R18 or 245/40R20 radial tires, depending on wheel configuration. That means this trim should be checked by actual wheel diameter before ordering, since the tire decision changes from an 18-inch fitment to a lower-profile 20-inch fitment.
The 2018 Buick LaCrosse Preferred uses the 235/50R18 radial size. For this trim, the main task is confirming that the car remains on 18-inch wheels, then deciding whether a traditional blackwall tire or a more appearance-driven sidewall treatment better suits the car.
The 2018 Buick LaCrosse Premium can use either 235/50R18 or 245/40R20 radial tires. Because this trim spans two wheel packages, the safest approach is to verify the wheel diameter on the car first and then compare the available tires within that exact size.
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.
Best 2018 Buick LaCrosse Tires for Sale
Available 2018 Buick LaCrosse tires span 18-inch, 19-inch, and 20-inch radial fitments from BFGoodrich, Nitto, and Pro-Trac. Depending on size, buyers can compare blackwall, redline, and raised white letter sidewalls across several g-Force, NT555 G2, Phenom T/A, and Street Pro III series options.
Common questions for the 2018 Buick LaCrosse usually center on trim-specific tire size, wheel diameter, available brands and sidewall styles, and what to inspect before putting the car back into regular road use.
Tire Size & Fitment
What tire size fits a 2018 Buick LaCrosse?
The 2018 Buick LaCrosse uses three tire sizes: 235/50R18, 245/45R19, and 245/40R20. The correct size depends on the exact sub-model and wheel package, so there is not one universal tire size for every 2018 LaCrosse.
The next step is matching the tire size to the wheel diameter actually on the car. Base and Preferred models use 235/50R18, while Avenir, Essence, and Premium trims can vary by wheel package. A quick check of the tire sidewall and wheel size helps prevent choosing an 18-inch tire for a 20-inch wheel or overlooking a trim-specific setup.
What size rim does a 2018 Buick LaCrosse use?
A 2018 Buick LaCrosse can use 18-inch, 19-inch, or 20-inch rims, depending on the sub-model and wheel package. Those rim diameters correspond to 235/50R18, 245/45R19, and 245/40R20 tire sizes.
Rim diameter is the first thing to confirm before ordering tires because the tire must match the wheel exactly. A trim like the Avenir can appear with either 19-inch or 20-inch fitment, and Essence or Premium can also vary. Looking at the current tire size on the car is usually the fastest way to verify which rim diameter the LaCrosse is using.
Why does the 2018 Buick LaCrosse have more than one tire size?
The 2018 Buick LaCrosse has more than one tire size because different trims and wheel packages were used across the model range. Some versions use 18-inch wheels with 235/50R18 tires, while others use 19-inch or 20-inch wheels with wider, lower-profile radial sizes.
That variation means tire selection should follow the exact trim and the actual wheel installed, not just the year and model name. It is also wise to confirm whether the car still has its original wheel package, since aftermarket wheels can change the fitment picture. Starting with wheel diameter keeps the search accurate and avoids a mismatch.
Choosing the Right Tire
What should I consider when choosing a 2018 Buick LaCrosse tire?
Start with the correct tire size for the trim and wheel diameter, since the 2018 Buick LaCrosse uses 235/50R18, 245/45R19, or 245/40R20 depending on configuration. After that, compare construction details such as rim-width compatibility, sidewall style, weight, and any stated load figures within the correct size.
The right choice depends on how the car is used and how you want it to look. A blackwall tire keeps the presentation understated, while redline or raised white letter options add a more distinctive appearance in certain sizes. It also helps to compare the actual wheel width on the car against the tire’s supported rim-width range before making a final selection.
What sidewall styles are available for 2018 Buick LaCrosse tires?
Sidewall styles for the 2018 Buick LaCrosse include blackwall, redline, and RWL, depending on tire size. Blackwall options are available across all three primary sizes, while redline and raised white letter choices appear in select 18-inch and 20-inch fitments.
That gives the LaCrosse owner a real appearance choice without changing the required tire size. A blackwall keeps the car looking contemporary and restrained, while redline or RWL can create a more custom or enthusiast-oriented presentation. The key is to choose the sidewall style only after confirming the correct size, since those appearance options are not offered in every LaCrosse fitment.
What brands offer tires for the 2018 Buick LaCrosse?
BFGoodrich, Nitto, and Pro-Trac offer tires for the 2018 Buick LaCrosse across its 18-inch, 19-inch, and 20-inch fitments. Depending on size, the available series include g-Force Sport Comp 2, g-Force Comp 2 AS, g-Force Phenom T/A, NT555 G2, and Street Pro III.
Brand choice is only part of the decision, since the tire series and sidewall treatment also change the character of the tire. Some sizes focus on blackwall performance-oriented radials, while others add redline or RWL versions. Once the correct size is confirmed, comparing the available brands becomes more useful because you are looking at products built for the same wheel diameter.
Restoration & Appearance
Which tire should I choose for a period-style 2018 Buick LaCrosse?
A period-style approach for a 2018 Buick LaCrosse starts with keeping the correct original size format for the trim and wheel package, whether that is 235/50R18, 245/45R19, or 245/40R20. Since this is a modern sedan, staying with a properly matched metric radial is the most natural way to preserve the car’s intended stance and proportions.
Appearance then becomes a matter of sidewall presentation and wheel setup rather than vintage construction. Blackwall tires suit a factory-inspired look, while redline or raised white letter choices create a more custom visual statement in select sizes. If originality matters closely, compare the current wheel-and-tire presentation against marque references and trim-specific photos before deciding.
How does tire selection affect the appearance of a 2018 Buick LaCrosse?
Tire selection changes the appearance of a 2018 Buick LaCrosse through wheel diameter, sidewall profile, and sidewall treatment. An 18-inch 235/50R18 setup presents more sidewall than a 20-inch 245/40R20 setup, and blackwall, redline, or raised white letter choices further change how understated or expressive the car looks.
That means appearance should be considered after the correct fitment is confirmed, not instead of it. A lower-profile tire on a larger wheel gives the LaCrosse a sharper visual edge, while the 18-inch fitment reads more balanced and traditional. Matching the tire to the trim and wheel package keeps the car’s proportions coherent and avoids an unintended look.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 2018 Buick LaCrosse?
Yes, modifications can affect tire fitment on a 2018 Buick LaCrosse. Aftermarket wheels, changes in wheel width, offset differences, suspension lowering, or body modifications can all alter the clearance relationship that the original 18-inch, 19-inch, or 20-inch tire sizes were designed around.
A LaCrosse with non-original wheels should be checked for actual wheel diameter and width before choosing replacement tires. Steering clearance, inner-fender space, and overall tire-to-body clearance matter just as much as the size printed on the sidewall. Even when the size looks familiar, a wheel change can shift the tire’s position enough to make careful measurement worthwhile.
What should I inspect before driving a 2018 Buick LaCrosse on new tires?
Before driving a 2018 Buick LaCrosse on new tires, inspect the wheels for damage, confirm the tire size matches the wheel diameter, and make sure each tire is inflated properly. It is also smart to check for uneven wear clues on the old tires, since those can point to alignment or suspension issues.
A short local drive is a good way to confirm there is no rubbing, vibration, or pull after installation. Recheck air pressure once the tires have settled, and pay attention to any signs of contact at full steering lock if the car has larger wheels or non-original suspension parts. Catching those issues early protects both the tires and the car.
How often should tires on a 2018 Buick LaCrosse be inspected?
Tires on a 2018 Buick LaCrosse should be inspected regularly, with a quick visual check before road trips and periodic closer inspections for tread wear, cracking, cuts, bulges, and air loss. Even a modern sedan that is not driven often can develop age-related tire issues while parked.
Consistent inspection matters because the LaCrosse uses lower-profile metric radials on some trims, and those tires can hide developing problems until the car is back on the road. Checking pressure, tread condition, and sidewall health helps preserve ride quality and handling. Cars that sit for long periods also benefit from clean storage conditions away from prolonged heat, sunlight, and ozone sources.
