Plus Sizing Tires & Wheels: Plus 1, Plus 2 & Plus 3 Explained

Plus sizing tires is the practice of increasing wheel diameter while choosing a tire with a shorter sidewall so the new tire-and-wheel combination keeps an overall diameter reasonably close to the original setup.

You may hear these changes described as Plus 1, Plus 2, or Plus 3. The number generally refers to how many inches the wheel diameter increases compared with the original wheel.

What Is Plus Sizing?

Plus sizing changes the relationship between wheel diameter and tire sidewall height.

Instead of simply installing a larger wheel with a tire of the same sidewall height, the tire dimensions are adjusted so the complete tire-and-wheel assembly remains closer to the original overall diameter.

This is important because a large change in overall tire diameter can affect speedometer readings, ride height, clearance, revolutions per mile, and other vehicle characteristics.

What Does Plus 1 Mean?

Plus 1 generally means increasing the wheel diameter by one inch compared with the original wheel.

For example, if a vehicle originally uses a 17-inch wheel, a Plus 1 setup would use an 18-inch wheel.

The replacement tire would normally use an 18-inch wheel diameter designation, while tire width and aspect ratio are selected so that the overall tire diameter remains reasonably close to the original setup.

What Does Plus 2 Mean?

Plus 2 generally increases wheel diameter by two inches.

If the original vehicle uses a 17-inch wheel, a Plus 2 setup would use a 19-inch wheel.

Because the wheel takes up more of the total tire diameter, the replacement tire typically uses a shorter sidewall than the original tire.

What Does Plus 3 Mean?

Plus 3 means increasing wheel diameter by three inches compared with the original wheel.

A vehicle originally equipped with a 17-inch wheel would therefore use a 20-inch wheel in a Plus 3 setup.

As the increase becomes larger, fitment checks become increasingly important because wheel width, tire width, offset, brake clearance, suspension clearance, load requirements, and available sidewall height all need to work together.

Plus 1 vs Plus 2 vs Plus 3

Setup	Original Wheel	New Wheel	General Change
Plus 1	17 in	18 in	1-inch increase in wheel diameter
Plus 2	17 in	19 in	2-inch increase in wheel diameter
Plus 3	17 in	20 in	3-inch increase in wheel diameter

The exact tire size cannot be determined from the wheel-diameter increase alone. The appropriate replacement depends on the original tire size, new wheel width, vehicle clearance, load requirements, and other fitment specifications.

Why Overall Tire Diameter Matters

Overall tire diameter is the total height of the mounted tire from one outer edge to the opposite outer edge.

Increasing wheel diameter without reducing tire sidewall height can substantially increase overall tire diameter.

A significant diameter change can affect:

• speedometer readings
• odometer readings
• ride height
• ground clearance
• fender clearance
• suspension clearance
• revolutions per mile
• vehicle-specific drivetrain behavior

Plus sizing attempts to control these changes by pairing a larger wheel with an appropriately sized lower-profile tire.

How Tire Sidewall Changes With Plus Sizing

When wheel diameter increases, the tire sidewall usually becomes shorter if the goal is to keep overall tire diameter relatively similar.

For a metric tire, sidewall height depends on both tire width and aspect ratio.

For example, a tire with a 55 aspect ratio has a sidewall height equal to approximately 55% of its nominal width. A lower aspect ratio generally results in a shorter sidewall relative to tire width.

If you need help reading the numbers, see our guide on how to read a tire size.

Example of Plus Sizing

Suppose a vehicle originally uses a 17-inch wheel. A possible plus-sizing progression might use:

• 17-inch wheel — original setup
• 18-inch wheel — Plus 1
• 19-inch wheel — Plus 2
• 20-inch wheel — Plus 3

The tire dimensions would need to change with each wheel size. You should not simply keep the same tire width and aspect ratio while increasing wheel diameter, because doing so would increase total tire diameter substantially.

How to Compare a Plus-Size Tire

Before choosing a plus-size setup, compare the original and proposed tire dimensions.

Important measurements include:

• tire width
• sidewall height
• overall diameter
• circumference
• revolutions per mile
• estimated speedometer difference
• ride-height change

Wheel Width Matters Too

Increasing wheel diameter does not necessarily mean the new wheel has the same width as the original.

A wider wheel can change:

• the appropriate tire-width range
• inner suspension clearance
• outer fender clearance
• the mounted shape of the tire
• the required wheel offset

Tire manufacturers specify approved wheel-width ranges for each tire model and size. Check those specifications before selecting a tire for a wider or narrower wheel.

Wheel Offset and Plus Sizing

Wheel offset is particularly important when changing wheel dimensions.

A wider wheel with an inappropriate offset can move the inner edge too close to suspension components or move the outer edge too far toward the fender.

See What Is Wheel Offset? for an explanation of positive, zero, and negative offset.

You can also use our Wheel Offset Calculator to compare inner clearance and outer wheel position when changing wheel width and offset.

Can Plus Sizing Affect Ride Quality?

It can. A shorter tire sidewall generally provides less flexible sidewall height between the wheel and road surface.

However, actual ride characteristics depend on many factors, including tire construction, tire pressure, vehicle suspension, wheel weight, road conditions, and the specific tire model.

Plus sizing should therefore be evaluated as a complete vehicle setup rather than assuming that every larger wheel will produce the same result.

Can Plus Sizing Affect Handling?

Changing tire width, sidewall height, wheel width, wheel weight, and wheel position can change how a vehicle responds.

A shorter sidewall may feel different during steering inputs, while changes in tire width and wheel offset can also influence vehicle behavior.

The actual result depends on the exact tire, wheel, suspension, alignment, and vehicle configuration.

Can Plus Sizing Affect the Speedometer?

Yes, if the replacement tire’s overall circumference differs from the original tire.

A tire with a larger circumference travels farther during each revolution, while a smaller tire travels a shorter distance.

Keeping total tire diameter relatively close to the original fitment helps limit this difference, but the exact comparison should still be calculated.

Use the Speedometer Difference Calculator to estimate how a tire-size change affects indicated speed.

Brake Clearance With Larger Wheels

A larger wheel diameter may provide more wheel-barrel space, but diameter alone does not guarantee brake clearance.

Brake fitment can also depend on:

• wheel-barrel shape
• spoke design
• wheel offset
• caliper dimensions
• vehicle brake package

Performance trims may use larger brake components than other versions of the same model, so wheel compatibility should be confirmed for the exact trim and brake package.

Load Rating and Plus Sizing

A plus-size tire and wheel setup still needs to meet the vehicle’s load requirements.

Check:

• tire load index
• tire load capacity
• wheel load rating
• recommended inflation requirements
• vehicle manufacturer specifications

A tire should not be selected only because its dimensions look suitable.

Plus Sizing and Vehicle Clearance

Even if overall tire diameter remains close to the original size, clearance can still change because the replacement tire may be wider and the wheel may use a different width or offset.

Check clearance around:

• fenders
• wheel-arch liners
• struts and springs
• control arms
• steering components
• brake components
• bodywork

Clearance should be considered during steering movement and suspension compression, not only while the vehicle is stationary.

How to Choose a Plus-Size Setup

A practical process is:

1. Confirm the original tire and wheel specifications for the exact vehicle.
2. Choose the proposed wheel diameter.
3. Confirm the wheel’s width, offset, bolt pattern, center bore, and load rating.
4. Select a tire designed for the new wheel diameter.
5. Confirm that the tire is approved for the new wheel width.
6. Compare the original and proposed tire dimensions.
7. Check load index and speed rating.
8. Check fender, suspension, steering, and brake clearance.
9. Consider any speedometer and ride-height differences.
10. Verify the setup for the exact year, make, model, trim, and configuration.

Can You Plus Size Any Vehicle?

Not every vehicle or configuration provides the same flexibility for wheel and tire changes.

Possible restrictions include:

• limited fender clearance
• large brake packages
• specific load requirements
• all-wheel-drive tire-diameter requirements
• unusual wheel offsets
• suspension geometry
• manufacturer restrictions

Research the exact vehicle before selecting a plus-size setup. Our Vehicle Tire & Wheel Fitment section provides available fitment records by year, make, model, and trim.

Plus Sizing vs Simply Installing Bigger Tires

Plus sizing and installing a larger overall tire are not necessarily the same thing.

Plus sizing generally increases wheel diameter while reducing sidewall height to keep overall tire diameter relatively close to the original.

Installing a larger tire may intentionally increase total tire diameter, which can change ride height, clearance, gearing-related behavior, and speedometer readings more significantly.

If you are considering a different overall tire size, see our guide: Can You Use a Different Tire Size?

Frequently Asked Questions

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Fitment note: Plus sizing is not determined by wheel diameter alone. Always verify the new wheel and tire combination for the exact vehicle, including wheel width, offset, bolt pattern, center bore, tire dimensions, load requirements, brake clearance, suspension clearance, and manufacturer guidance.