The 2018 BMW i3 stands apart from most modern BMWs, blending lightweight construction, city-focused efficiency, and a distinctive narrow-tire stance that is central to the way the car looks and drives. Its tall, slim tire package is part of the i3’s engineering story, not just a styling detail. This model uses four radial tire sizes across 19-inch and 20-inch wheel setups, with narrower front sizes and wider rear sizes depending on configuration. That makes tire selection less about broad experimentation and more about matching the correct front or rear fitment, wheel diameter, and overall appearance. Owners should start by confirming wheel size and axle position before comparing replacement choices.
Which Tire Size Is Right for The 2018 BMW i3
The 2018 BMW i3 uses four primary tire sizes, and the right choice depends first on wheel diameter and whether the tire is for the front or rear axle. This is a radial-only fitment, with 19-inch and 20-inch setups using different front and rear pairings. Before selecting a tire, confirm the car’s actual wheel package and whether you are replacing a front tire, a rear tire, or a full staggered set.
Fit(s): Base, Base Front, and Range Extender Front
Construction: Radial|Rim: 19 in
155/70R19 is a metric radial size where 155 is the section width in millimeters, 70 is the aspect ratio, R identifies radial construction, and 19 is the wheel diameter in inches. On the 2018 BMW i3, this is one of the narrow front-tire fitments used with a 19-inch wheel setup. Its tall, slim profile is part of the i3’s distinctive low-drag tire strategy rather than a generic compact-car size. Choose this size when the vehicle is equipped with 19-inch front wheels and the goal is to keep the intended front fitment and proportions in place.
155/60R20 follows the same metric radial format, with a 155-millimeter section width, 60-series profile, radial construction, and a 20-inch rim diameter. For the 2018 BMW i3, this is the narrow front-tire size used on the 20-inch wheel package. Compared with the 19-inch front fitment, the key difference is not just tread width but the wheel diameter the tire is built around. This size should be evaluated when the car has 20-inch front wheels and the front axle fitment needs to match that specific setup.
175/55R20 is a metric radial size with a 175-millimeter section width, 55-series sidewall profile, radial construction, and a 20-inch rim diameter. On the 2018 BMW i3, this is a rear-tire fitment for cars using the 20-inch staggered setup, with more width than the matching front size. That wider rear sizing is an important part of the i3’s axle-specific fitment and should not be confused with the front tire simply because both share the same wheel diameter. Confirm rear position and 20-inch wheels before selecting this size.
175/60R19 uses the modern metric radial format, with 175 denoting section width in millimeters, 60 as the aspect ratio, R for radial construction, and 19 for rim diameter in inches. On the 2018 BMW i3, this size serves as a rear fitment on the 19-inch wheel package, pairing with a narrower front tire on the same diameter wheel. The wider rear sizing matters because the i3 does not use the same size at all four corners in these staggered applications. This is the correct direction to evaluate when replacing a 19-inch rear tire and keeping the original front-to-rear sizing relationship.
Sub-model fitment on the 2018 BMW i3 is tied closely to front-versus-rear position and to whether the car carries a 19-inch or 20-inch wheel setup. Checking the exact sub-model name matters because the i3 uses staggered sizing, and the front and rear tire sizes are not interchangeable.
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2018 BMW i3 Base
The 2018 BMW i3 Base is associated with the 155/70R19 radial size, which places it within the 19-inch fitment family. That makes wheel confirmation especially important before ordering replacements, since other i3 configurations use different front and rear sizes on 19-inch or 20-inch setups.
The 2018 BMW i3 Base Front uses a narrow front radial fitment and appears with both 155/70R19 and 155/60R20 depending on wheel package. Tire selection here starts with confirming whether the car has 19-inch or 20-inch front wheels rather than assuming all Base models share one front size.
The 2018 BMW i3 Base Rear uses a wider rear radial fitment, with either 175/60R19 or 175/55R20 depending on the wheel setup. That means rear replacement should always be matched to both axle position and wheel diameter so the car keeps its intended staggered tire arrangement.
The 2018 BMW i3 Range Extender Front uses the same narrow front sizing pattern as other front-position i3 fitments, with either 155/70R19 or 155/60R20. Choosing between them comes down to verifying the actual front wheel diameter on the car before comparing tire options.
The 2018 BMW i3 Range Extender Rear follows the wider rear fitment pattern, using either 175/60R19 or 175/55R20. Rear tire replacement should stay focused on the correct wheel diameter and rear position so the staggered setup remains properly matched.
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 2018 BMW i3 tire FAQs focus on the narrow front and wider rear fitments, the difference between 19-inch and 20-inch wheel packages, and the practical checks that matter before replacing tires on this axle-specific setup.
Tire Size & Fitment
What tire size fits a 2018 BMW i3?
The 2018 BMW i3 uses four tire sizes: 155/70R19, 155/60R20, 175/55R20, and 175/60R19. The narrower 155-section sizes are front fitments, while the wider 175-section sizes are rear fitments, and the correct choice also depends on whether the car has 19-inch or 20-inch wheels.
That means the first step is confirming both wheel diameter and tire position on the car. A front i3 tire and a rear i3 tire are not the same size, and a 19-inch setup uses different sizes than a 20-inch setup. Checking the sidewall on the current tire and verifying the actual wheel package helps avoid mixing front and rear fitments.
What size rim does a 2018 BMW i3 use?
The 2018 BMW i3 uses either 19-inch or 20-inch rims, depending on the wheel package installed on the car. The 155/70R19 and 175/60R19 sizes are built for 19-inch wheels, while the 155/60R20 and 175/55R20 sizes are built for 20-inch wheels.
Rim diameter should be confirmed before looking at tread pattern or brand, because a tire for a 19-inch wheel cannot be used on a 20-inch wheel. On the i3, that check is especially important because the car also uses staggered front and rear sizing. The right replacement has to match both the wheel diameter and the axle position.
Why does the 2018 BMW i3 have more than one tire size?
The 2018 BMW i3 has more than one tire size because it uses axle-specific fitment and more than one wheel diameter. Front sizes are narrower than rear sizes, and both 19-inch and 20-inch wheel packages are used across the model, creating four total size combinations.
That layout means the correct replacement is determined by the car’s actual setup, not just by year and model alone. A buyer should confirm whether the tire being replaced is on the front or rear and whether the car has 19-inch or 20-inch wheels. On a vehicle like the i3, assuming all four tires are the same size can lead to an incorrect match.
Choosing the Right Tire
What should I consider when choosing a 2018 BMW i3 tire?
Start with the exact tire size already assigned to the wheel position being replaced. On a 2018 BMW i3, that means matching front or rear placement and confirming whether the car uses the 19-inch or 20-inch package, since the i3 combines narrow front tires with wider rear tires.
After size and wheel diameter are confirmed, compare the replacement tire’s overall dimensions to the current setup and make sure the wheel itself has not been changed. This matters even more on an i3 because its tire package is unusually narrow and axle-specific. A careful match helps preserve intended clearance, stance, and the front-to-rear relationship built into the car.
How do I choose between the available 19-inch and 20-inch tire fitments for a 2018 BMW i3?
The choice is not really between 19-inch and 20-inch tire sizes in the abstract; it is about matching the wheel package already on the car. A 2018 BMW i3 with 19-inch wheels uses 155/70R19 front and 175/60R19 rear, while a 20-inch setup uses 155/60R20 front and 175/55R20 rear.
A buyer should inspect the wheel and current sidewall markings before selecting replacements. Wheel diameter determines the correct tire family, and the front and rear sizes must stay in their proper positions. If the car has had wheel changes at some point, confirming the actual installed setup is more reliable than assuming the original package is still in place.
How do I choose between the available front and rear tires for a 2018 BMW i3?
The 2018 BMW i3 uses different tire sizes front and rear, so selection begins with axle position. Front tires are the narrower 155-section sizes, while rear tires are the wider 175-section sizes, and each pair also changes with 19-inch or 20-inch wheel diameter.
That staggered arrangement means the rear tire should not be chosen simply because it shares the same model year or wheel style as the front. Check the sidewall size on the tire being replaced, confirm the wheel diameter, and verify whether the replacement is for the front or rear axle. Keeping that distinction clear is the key to choosing the right i3 tire.
Restoration & Appearance
Does correct tire fitment matter for a 2018 BMW i3 restoration or preservation project?
Yes. On a 2018 BMW i3, correct tire fitment matters because the car’s narrow, tall tire proportions are a visible part of its design and engineering character. Using the proper front and rear sizes on the correct 19-inch or 20-inch wheel package helps preserve the i3’s distinctive stance and overall presentation.
Preservation-minded owners should verify the current wheel setup before replacing tires, especially if the car has changed hands or seen wheel swaps. Matching the original-style size layout is usually more important here than experimenting with unrelated modern sizes. When exact appearance matters, keeping the intended front-to-rear sizing relationship is part of maintaining the i3’s visual identity.
How does tire size affect the appearance of a 2018 BMW i3?
Tire size has a strong effect on the appearance of a 2018 BMW i3 because the car was designed around very narrow tires with relatively tall overall proportions. The difference between 19-inch and 20-inch setups, along with the wider rear sizes, contributes to the i3’s unusual and instantly recognizable profile.
Owners who care about preserving that look should avoid treating the tires as generic compact-car replacements. The visual balance comes from using the right front and rear pairing for the wheel package already on the car. Even small departures from the intended size family can change the way the wheels fill the arches and how the car sits overall.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 2018 BMW i3?
Yes. Modifications can affect tire fitment on a 2018 BMW i3, especially if the car has aftermarket wheels, changed offsets, suspension alterations, or nonstandard ride height. Because the i3 already uses narrow, axle-specific sizes on either 19-inch or 20-inch rims, even modest changes can affect clearance or proper size selection.
Anyone replacing tires on a modified i3 should confirm the actual wheel diameter and inspect the current tire sidewall before ordering. It also helps to check steering clearance, rear clearance, and how close the tire sits to suspension components. The more the car differs from stock wheel and suspension setup, the more important those checks become.
What should I inspect before driving a 2018 BMW i3 on new tires?
Before driving a 2018 BMW i3 on new tires, inspect the installed size on each axle, verify proper inflation, and make sure each tire is mounted on the correct wheel diameter. It is also wise to confirm that front tires are on the front and rear tires are on the rear, since the i3 uses a staggered setup.
A short walkaround should include checking for any rubbing at full steering lock, uneven seating on the wheel, visible sidewall damage, and any loss of air after installation. On a low-use or recently purchased i3, it also makes sense to inspect the wheels for prior damage and make sure the overall setup matches the intended 19-inch or 20-inch package.
How often should tires on a 2018 BMW i3 be inspected?
Tires on a 2018 BMW i3 should be inspected regularly, especially because the car uses specialized narrow sizes and staggered front-to-rear fitment. A quick visual check for pressure loss, cuts, bulges, unusual wear, and sidewall damage should be part of routine ownership, even if the car is driven mostly for short urban trips.
Longer intervals between drives can make tire condition easy to overlook, so owners should also inspect age-related condition and verify that wear remains even across each axle. Checking the sizes during inspection is useful as well, since the i3’s front and rear tires differ. Consistent inspections help catch fitment mistakes, damage, or air-loss issues before they become larger problems.
