2008 Infiniti Tire Fitment Guide

2008 Infiniti vehicles use five tire sizes across four model lines: 225/55R17 for the G35, 225/50R18 for the G35 and G37, 245/45R18 for the G35, M35, and M45, 225/45R19 for the G37, and 245/40R19 for the G37, M35, and M45. The rim diameters are not all the same, so the lineup spans 17-, 18-, and 19-inch wheels rather than one interchangeable wheel size.

That means the first fitment question for a 2008 Infiniti is your exact model and wheel diameter, not simply year and make. Rim width ranges also differ by size: 225/55R17 works with roughly 6.0 to 9.0 inches depending on tire, 225/50R18 with 6.0 to 8.0 inches, 245/45R18 with 7.5 to 9.0 inches, 225/45R19 with 7.0 to 8.5 inches, and 245/40R19 with 8.0 to 9.5 inches.

On a 2008 Infiniti, 225/55R17 means the tire is 225 millimeters wide, has a 55-series aspect ratio, uses radial construction, and mounts on a 17-inch wheel. In this year and make, that size is tied to the G35 rather than the whole Infiniti lineup. Available versions center on modern radial performance tires, and the sidewall style can be either blackwall or wide whitewall depending on the exact product.

For a buyer, the important part is that 225/55R17 is not just a generic 17-inch tire. The overall proportions, wheel diameter, and approved rim-width range all need to line up with the wheel already on the car. If your 2008 Infiniti G35 wears 17-inch wheels, this size is the place to start; if your car has 18- or 19-inch wheels, moving to this size would require more than simply choosing a different tire.

No, 2008 Infiniti models do not use one common tire size. The G35 spans 17-inch and 18-inch sizes, the G37 uses 18-inch and 19-inch sizes, and the M35 and M45 use 18-inch and 19-inch sizes that overlap with some G-series fitments but not all of them. Even when two models share a size, that does not mean every wheel package across the year and make is interchangeable.

That is why identifying the car as a G35, G37, M35, or M45 should come before comparing brands or tread styles. If the car has been modified, confirm the sidewall markings on the tire already fitted and measure the wheel diameter directly. Treat the factory size family as your baseline, then compare the exact size to the actual wheel and the intended use of the car before choosing a replacement.

Most 2008 Infiniti tire sizes here are available in blackwall form, which is the standard visual look for modern performance-luxury cars of this period. The exception is 225/55R17, where BFGoodrich also offers a wide whitewall version alongside blackwall choices. That whitewall style changes the appearance substantially and is much more of a custom or stylistic statement than a factory-correct late-2000s Infiniti look.

For most owners, blackwall is the natural match for the original character of a 2008 Infiniti G or M. The whitewall option may appeal if a G35 is being personalized rather than kept visually stock. Because sidewall styling is size-specific, it helps to decide early whether you are aiming for original modern appearance or a more distinctive custom look, then narrow the tire choice within the correct wheel diameter.

BFGoodrich covers every 2008 Infiniti size used here, including 225/55R17, 225/50R18, 245/45R18, 225/45R19, and 245/40R19. Nitto also appears in 245/45R18, giving that size a second brand option. Within BFGoodrich, the available series include g-Force Comp-2 A/S, g-Force Sport Comp-2, g-Force Phenom T/A, and, in 225/55R17, the Silvertown Radial.

That brand spread means some sizes have broader comparison shopping than others. If you need 245/45R18, you can compare BFGoodrich and Nitto directly; if you need one of the other sizes, the decision is more about series, load rating, speed rating, and appearance within the BFGoodrich family. It is worth checking the exact sidewall marking and intended use of the car instead of choosing only by brand name.

For 2008 Infiniti fitments where both appear, the difference comes down to the exact size, speed rating, load figure, and wheel-width compatibility attached to each product. In 245/45R18, for example, g-Force Sport Comp-2 carries a 96W marking with a 1,565-pound load figure at 51 psi, while g-Force Phenom T/A carries a 100Y marking with a 1,764-pound load figure at 50 psi. In 225/45R19 and 245/40R19, the Phenom T/A also carries a Y rating while the Sport Comp-2 remains W rated.

Those differences do not automatically make one tire right for every 2008 Infiniti. They do mean you should compare the exact size, speed symbol, and approved rim-width range against your wheel and how the car is used. If the goal is simply staying within the proper factory size, either series may work where offered, but the sidewall marking and fitment range should be confirmed before treating them as interchangeable.

Rim width requirements for 2008 Infiniti tires vary by size. 225/55R17 works with rims from about 6.0 to 8.0 inches in most versions, with one BFGoodrich Silvertown Radial extending to 9.0 inches. 225/50R18 fits 6.0 to 8.0 inches, 245/45R18 fits 7.5 to 9.0 inches, 225/45R19 fits 7.0 to 8.5 inches, and 245/40R19 fits 8.0 to 9.5 inches.

That matters because the same wheel diameter does not guarantee the same wheel width. A 19-inch Infiniti wheel still needs to fall within the approved width range for the exact tire size being used. If the car has aftermarket wheels, verify both diameter and measured width before ordering. Staying inside the tire maker’s approved range helps preserve the intended tread shape, steering response, and sidewall behavior.

No, original 2008 Infiniti wheels cannot be treated as universal across all five sizes because the lineup uses 17-, 18-, and 19-inch rim diameters. A G35 on 17-inch wheels uses 225/55R17, while other G and M applications move to 18-inch or 19-inch sizes. Even among the sizes that share the same diameter, the approved rim-width ranges are different enough that one tire size should not be assumed to suit every wheel of that diameter.

The practical approach is to confirm the wheel diameter first and then compare the wheel’s actual width to the tire’s approved range. That is especially important on cars that may have changed hands, received dealer-installed wheel packages, or been modified. If the wheel remains factory original, matching the sidewall marking on the existing tire is usually the fastest starting point before comparing specific replacement products.

A 2008 Infiniti should be stored in a cool, dry space away from direct sunlight, electric motors, welders, chargers, and other ozone-producing sources that can accelerate sidewall aging. Keep the tires inflated to an appropriate stored pressure, make sure the floor stays dry, and move the car periodically if it will sit for long stretches. These are all radial fitments, so flat-spotting is usually less pronounced than with older bias-ply tires, but long static storage still ages rubber.

If the car will be parked for months at a time, rolling it occasionally or supporting it properly can reduce localized stress on the contact patch. A clean storage environment also protects wheels and valve stems, not just the tread and sidewalls. Before putting a stored 2008 Infiniti back into regular use, inspect each tire closely for cracking, pressure loss, or irregular shape rather than assuming a good-looking tread surface tells the whole story.

On a 2008 Infiniti, tire age usually matters more than mileage, especially on enthusiast-owned or low-use cars. A sound rule is to begin evaluating tires carefully once they are around five to seven years old and to treat about ten years from the date code as a strong point for replacement consideration, even if tread depth still appears acceptable. Heat cycles, storage conditions, and inflation history can shorten that timeline.

The date code on the sidewall gives a better picture of service life than odometer readings alone. A 2008 Infiniti that spends much of its life parked can still age out its tires well before wearing them out. If the car is driven spiritedly, at highway speeds, or on long trips, old rubber deserves even more scrutiny. When in doubt, age, cracking, and hardening should carry more weight than remaining tread depth.

Tires on a 2008 Infiniti should be checked before every drive and given a more thorough inspection before any longer outing. Look for uneven wear, sidewall cracks, punctures, cuts, bulges, and any loss of pressure from one tire to another. Because these cars use lower-profile radial sizes in many applications, curb damage and inner-sidewall issues can be easy to miss without a close look.

A quick visual check is enough for routine local use, but a longer trip deserves a pressure check, tread inspection, and a look at the spare as well. Pay attention to steering vibration or a pull that develops suddenly, since either can point to tire damage or a pressure problem. Keeping inspection intervals short is one of the simplest ways to protect both the tires and the more sophisticated suspension feel these Infiniti models were known for.

Yes, the 2008 Infiniti tire sizes here are modern radial fitments with speed ratings that support normal highway use when the tires are in good condition and properly matched to the car. Most products in these sizes carry a W rating, which corresponds to 168 mph, while some BFGoodrich Phenom T/A versions in 245/45R18, 225/45R19, and 245/40R19 carry a Y rating, which corresponds to 186+ mph. Those figures exceed ordinary U.S. highway speeds by a wide margin.

Real-world safety still depends more on tire age, inflation, wheel condition, alignment, and the overall mechanical health of the 2008 Infiniti than on the speed symbol alone. A luxury-performance sedan can feel very stable at speed, which makes regular inspections even more important. If the car has old tires, uneven wear, or unknown service history, resolve those issues before treating any speed rating as meaningful protection on the road.

Inflation pressure for a 2008 Infiniti should follow the vehicle placard or owner’s manual for the factory recommendation, then be checked against the tire maker’s guidance for the exact replacement tire. Several tires here include maximum load and pressure figures such as 1,609 pounds at 51 psi for one 225/55R17, 1,709 pounds at 50 psi for 225/50R18, 1,565 to 1,764 pounds around 50 to 51 psi for 245/45R18, 1,565 pounds at 50 psi for 225/45R19, and 1,653 pounds at 50 psi for 245/40R19.

Those maximum figures are not a blanket recommendation for everyday cold inflation. They are load-capacity references tied to the tire itself. The right working pressure depends on the exact 2008 Infiniti model, axle load, and tire chosen, so do not transfer a number from one size to another just because the car belongs to the same year and make. Start with the vehicle recommendation, then fine-tune only within the tire maker’s approved range.

Before a longer drive in a 2008 Infiniti, inspect all four tires for cracking, punctures, bulges, uneven wear, and any signs of impact damage from potholes or curbs. Confirm cold inflation pressure, check tread depth across the full width, and make sure the spare is usable if the car still carries one. On 18-inch and 19-inch fitments especially, it is worth looking closely for wheel damage that can affect how the tire seats and holds air.

A good pre-trip check also includes the rest of the car, because tire condition is only one part of highway readiness on a performance-luxury vehicle. Brakes, suspension, alignment, and battery health all affect how confidently a 2008 Infiniti will travel at speed. If the tires are older, recently repaired, or new to you, keep the first trip conservative and recheck pressures afterward to make sure everything is settling in normally.