245/45R17 Tire Size Guide

The 245/45R17 size code breaks down into three main measurements plus the construction type. The 245 is the section width in millimeters, the 45 means the sidewall height is 45 percent of that width, the R indicates radial construction, and the 17 is the wheel diameter in inches.

Unlike older alphanumeric or numeric sizing systems, 245/45R17 gives you a direct width measurement and a direct aspect ratio right in the code. It does not tell you everything, though. Load rating, speed category, sidewall style, and exact tread purpose still depend on the individual tire, so those markings should be checked separately when comparing replacement options.

The 245/45R17 fits a 17.0-inch wheel, which equals 431.8 millimeters at the bead seat. That diameter must match exactly, because a 17-inch tire cannot be safely mounted on a wheel of any other diameter even if the width looks close.

Wheel width matters almost as much as wheel diameter on a low-profile size like this one. Most examples of the 245/45R17 are designed around rim widths from 7.50 to 9.00 inches, and staying within that range helps preserve the intended sidewall shape, tread contact, and clearance. Buyers should also check wheel offset and brake package space, since diameter alone does not settle fitment.

The 245/45R17 has a section width of 245 millimeters, which converts to 9.65 inches. Section width is the tire's widest inflated point from sidewall to sidewall, not the width of the tread that actually contacts the road.

Clearance questions usually start with section width because that is the part most likely to crowd suspension pieces, inner wheelhouses, or outer fender lips. Tread width can be narrower than the section measurement, so judging fit by tread alone can be misleading. On a size like 245/45R17, wheel width and offset can also change how that width sits in the opening.

The 245/45R17 has an overall diameter of 25.68 inches, or about 652.27 millimeters. That number represents the tire's full outside height from the ground to the top of the tread when measured through the center of the mounted, inflated tire.

Overall diameter affects more than appearance. It influences ride height, wheel-opening fill, and the way a vehicle's speedometer and odometer compare with actual road speed and distance. When buyers consider a substitute size, this is one of the first numbers to compare because even modest changes in diameter can alter stance and clearance at both the top and rear of the wheel opening.

The sidewall height on the 245/45R17 is 4.34 inches, which equals 110.25 millimeters. That measurement runs from the wheel's bead seat to the outer edge of the tread on one side of the tire.

A 45-series sidewall is noticeably shorter than a taller touring or vintage-style profile, and that changes both appearance and road feel. Shorter sidewalls generally contribute to quicker steering response and a firmer character, while also giving the tire a more modern, lower-profile look. Buyers changing from a taller size should compare ride quality expectations, wheel protection, and fender gap before making the switch.

The 245/45R17 turns about 785.3 revolutions per mile. In simple terms, that is how many complete rotations the tire makes while the vehicle travels one mile.

Revolutions per mile are useful when comparing substitute sizes because they show how closely one tire matches another in rolling height. A replacement with a noticeably different figure can change speedometer and odometer readings, and on some vehicles it may also affect shift timing or electronic calibration. Buyers trying to preserve original road manners should compare this number along with overall diameter.

No. The 245/45R17 shares a 17-inch wheel diameter with many other sizes, but rim diameter alone does not make it interchangeable. Section width, sidewall height, wheel width, offset, and available clearance all have to work together for the size to fit correctly.

A vehicle originally designed around a narrower or taller tire may react differently to a 245/45R17 in steering, fender clearance, or wheel-opening appearance. Buyers should compare the complete tire size already on the car, inspect inner and outer clearance, and confirm that the wheel falls within the 7.50 to 9.00 inch width range before assuming a 17-inch fitment is enough.

The 245/45R17 is built for wheels from 7.50 to 9.00 inches wide. Staying in that span helps the tire keep the sidewall profile and tread shape it was designed to have.

Mounting the tire on a wheel that is too narrow can pinch the sidewalls inward and make the tire stand taller and rounder than intended. Using a wheel that is too wide can flatten the profile and change how the tread sits on the road. For buyers concerned with appearance as well as function, rim width has a direct effect on stance, shoulder shape, and fender clearance.

It can, but the answer depends on the vehicle and the goal of the build. The 245/45R17 is a modern radial size, so it is generally better suited to later performance-oriented cars or restomod-style projects than to an earlier factory-correct restoration.

Drivers often choose radial construction for more familiar modern-road behavior, while judged originality may call for a different size or construction on some vehicles. If authenticity matters, compare the original documentation, the wheel dimensions, and the car's intended use before settling on this size. If regular road use matters more, the 245/45R17 can be a practical way to retain contemporary proportions.

The 245/45R17 usually delivers a firmer, more immediate feel than a taller-profile tire because its sidewall is only 4.34 inches tall. On a radial construction, that lower sidewall height often translates to quicker steering response and less visual sidewall movement during cornering.

Ride quality still depends on the vehicle, suspension condition, wheel width, and inflation level, not just the size code. A car with worn shocks or aggressive alignment can feel much harsher than the same size on a well-sorted chassis. Buyers who want factory-like comfort should compare this size carefully against any taller original fitment before changing proportions.

The 245/45R17 is widely associated with modern passenger-car use, so it is a familiar size for regular road service when the individual tire's load and speed markings match the vehicle's needs. Its radial construction and moderate overall diameter make it a common size for drivers who want responsive road manners without moving to an unusually short tire.

Highway behavior is shaped by more than the size alone. Tire age, alignment, suspension bushings, wheel balance, and the specific tire category all influence straight-line stability and braking feel. A street-oriented version of the 245/45R17 may behave very differently from one built for specialized drag use, so the exact tire should match the way the car is driven.

A 245/45R17 generally gives a lower-profile look and a sharper steering response than a taller tire with the same section width. Because the overall diameter is 25.68 inches, replacing it with a noticeably taller or shorter size can change wheel-opening fill, effective gearing feel, and speedometer behavior.

Drivers considering a substitute should compare overall diameter, revolutions per mile, and section width together rather than looking at width alone. A tire that is only slightly different on paper can still alter stance or clearance at the top of the fender. On performance-oriented cars, those changes may also affect the visual balance between front and rear tires.

The 245/45R17 is available from BFGoodrich, M&H Racemaster, Nitto, and Pro-Trac. That spread covers both general street-oriented radial options and more specialized choices within the same basic size.

Brand selection in this size should start with intended use rather than name recognition alone. Some versions are aimed at everyday street driving, some emphasize performance-road manners, and some are built for drag-focused applications. Buyers should compare sidewall markings, wheel-width compatibility, and load details so the tire matches the vehicle's actual job instead of just the size code.

Quality comparison in the 245/45R17 starts with construction consistency, clear sidewall markings, proper wheel-width compatibility, and a tire category that matches the vehicle's use. A well-chosen size on the wrong type of tire can be more disappointing than a less famous brand that actually suits the car.

Buyers should also think in sets, not single tires. Matching construction type, similar load capability, and a consistent visual look across all four corners matter for drivability and appearance. On a low-profile radial size like this, small differences in sidewall shape or intended use can change the way the car feels, so compare the complete specification rather than the nominal size alone.

Sidewall style can be a meaningful choice in the 245/45R17 because this size appears in blackwall, redline, and raised white letter versions. The sidewall treatment does not change the size code, but it can strongly influence how the tire looks on a muscle car, restomod, or later-model performance build.

Appearance should still be balanced with the tire's purpose. A buyer may prefer a redline or raised white letter look, but the tire also needs the right construction, load suitability, and road-use category for the vehicle. If visual authenticity matters, choose a sidewall style that matches the era and personality of the car without overlooking wheel and clearance requirements.

A 245/45R17 in regular service should be inspected routinely for uneven wear, cuts, sidewall cracking, punctures, and air loss. Low-profile tires can show the effects of alignment issues and impact damage quickly, so a visual check during pressure checks or wash days is a good habit.

Regular inspection matters because the size alone does not protect against age, road hazards, or setup problems. Look closely at the inner shoulder as well as the outer sidewall, especially on performance cars that may run wider wheels or more aggressive alignment. If the vehicle starts pulling, vibrating, or losing pressure, the tire and wheel assembly should be checked before more miles are added.

Even an occasionally driven 245/45R17 can age out before the tread is gone. Time, heat cycles, sunlight, ozone exposure, and long periods of sitting all affect the rubber, so low mileage by itself does not guarantee a tire is still fit for continued use.

Collector and hobby vehicles often accumulate miles slowly, but they still need periodic condition checks. Store the car away from direct sunlight, electric motors, and damp conditions when possible, and inspect the tires before any long drive after storage. Cracking, hardening, flat spotting that does not clear, or repeated pressure loss are all signs to evaluate the tire more closely.

The 245/45R17 is normally a tubeless fitment. In practice, tube use is still a wheel-and-tire-system question rather than a size question, so the actual tire, wheel design, and manufacturer guidance should be confirmed before installation.

Most buyers looking at this size will be pairing it with modern one-piece passenger-car wheels, where tubeless use is the usual setup. If the wheel has damage, corrosion at the bead seat, or an unusual construction, the correct approach can change. When there is any doubt about the wheel condition or tire specification, a qualified tire professional should inspect the full assembly.

The 245/45R17 should be replaced when age, cracking, bulges, repeated air loss, impact damage, or uneven wear make its condition questionable, even if tread depth still looks acceptable. Tread is only one part of the decision, especially on low-profile tires used on heavier or higher-performance vehicles.

Road use places demands on the sidewall, belt package, and bead area that are not always visible from a quick glance at the tread surface. Before long trips, inspect the full tire closely and review the date and current sidewall markings on the tire in service. If condition, age, or prior repairs raise doubts, replacement is the safer path than stretching its service life.

Load rating is critical on the 245/45R17 because products in this size do not all carry the same load at the same pressure. Examples in this size range from 1,279 pounds at 35 psi to 1,709 pounds at 50 psi, so the exact tire's markings must match the vehicle's real requirements.

Choosing by size alone can overlook an important difference between specialized and general-use tires. A street car, luxury sedan, or performance coupe may need a different load capacity than a drag-focused application in the same nominal size. Buyers should compare the tire's full sidewall specification with the vehicle placard, axle loads, and intended use before installation.

Buyers should verify condition, age, wheel compatibility, load capability, and the exact sidewall markings before relying on a 245/45R17 in modern traffic. The size itself is common, but different tires within that size can be aimed at different uses and can carry different ratings.

Wheel width should stay within the 7.50 to 9.00 inch range, and the 17-inch rim diameter must match exactly. It is also smart to inspect for prior damage, confirm the tire is appropriate for the way the vehicle will be driven, and review local requirements rather than assuming every tire in the size serves the same purpose. If fitment or condition is uncertain, professional inspection is worthwhile.