2005 Infiniti Tire Fitment Guide

2005 Infiniti vehicles use nine tire sizes across two model lines. The G35 uses 215/55R17, 225/50R17, 235/50R17, 225/45R18, 235/45R18, 245/45R18, 225/40R19, and 245/40R19, while the Q45 uses 225/55R17 and 245/45R18. The only size shared by both models is 245/45R18. Rim-width ranges vary by size, starting at 6.0 to 7.5 inches for 215/55R17, 6.0 to 8.0 inches for several 17-inch sizes, 7.0 to 8.5 inches for 225/45R18, and extending to 8.0 to 9.5 inches for 245/40R19.

That means year and make alone are not enough for a confident tire choice on a 2005 Infiniti. G35 owners especially need to confirm whether the car has a 17-, 18-, or 19-inch package, and Q45 owners need to separate the 17-inch 225/55R17 fitment from the 18-inch 245/45R18 setup. Checking the current tire sidewall and wheel diameter before ordering is the quickest way to avoid crossing between similar but incorrect sizes.

On a 2005 Infiniti, 225/45R18 is a metric radial code. The 225 is the nominal section width in millimeters, 45 is the aspect ratio, R means radial construction, and 18 is the wheel diameter in inches. On the 2005 Infiniti range, that size belongs to the G35. Tires in this size mount on 18-inch wheels and work within a 7.0 to 8.5 inch rim-width range depending on the specific tire.

Understanding that code helps you separate it from nearby G35 sizes such as 235/45R18 or 245/45R18, which are also 18-inch radials but are wider and require different wheel widths. Even when the wheel diameter matches, the width and profile are not interchangeable choices to make casually. If your G35 already wears 225/45R18, staying with that exact size preserves the intended relationship between tire width, sidewall height, and wheel fit.

No, 2005 Infiniti models do not all use the same tire size. The G35 spans eight sizes across 17-, 18-, and 19-inch wheel packages, while the Q45 uses two sizes on 17- and 18-inch wheels. Only 245/45R18 overlaps between both models. Every other size is model-specific, and several G35 sizes are tied to different wheel and performance packages rather than to the whole model line.

That split matters because a G35 owner cannot assume that another G35’s size is correct without checking the actual wheel package, and a Q45 owner should not borrow fitment assumptions from the sportier G35. The safest approach is to verify the sidewall code already on the car or confirm the wheel diameter first, then narrow the options within that exact size. That avoids moving into a wider, taller, or lower-profile fitment that changes the car’s stance and intended setup.

Most 2005 Infiniti tire sizes are available in Blackwall form, which matches the contemporary luxury and sport-sedan look these cars originally carried. The exception is 225/55R17 for the 2005 Infiniti Q45, where both Blackwall and Wide Whitewall options exist. That gives Q45 owners a choice between a modern stock-like appearance and a more stylized presentation. G35 sizes remain strictly Blackwall across the available tire range.

For most buyers, the decision is visual rather than mechanical because the sidewall treatment does not change the basic size code. A Blackwall tire will look most natural on a factory-appearing G35 or Q45, while the whitewall option on the Q45 appeals more to owners customizing the sedan’s appearance. If originality matters, compare your car’s current look and intended presentation before choosing, especially on a flagship sedan where wheel-and-tire appearance has a strong effect on the car’s character.

2005 Infiniti tires are available from BFGoodrich and Nitto, depending on size. BFGoodrich covers every active size in this year-and-make range, while Nitto appears in 225/50R17, 225/45R18, and 245/45R18. Several sizes such as 235/50R17, 225/40R19, 245/40R19, 215/55R17, 235/45R18, and 225/55R17 are served entirely by BFGoodrich. All of the available choices are radial designs aimed at modern road use.

That brand spread gives the broadest choice to G35 owners in a few popular 17- and 18-inch sizes, while Q45 owners have the most variety in 225/55R17 because that size also brings a whitewall option. If you are comparing brands, start with the exact size first and then look at differences in load rating, speed rating, and appearance within that size. A strong brand preference only helps after the fitment itself is confirmed.

On several 2005 Infiniti sizes, BFGoodrich g-Force Comp 2 A/S and BFGoodrich g-Force Phenom T/A overlap in the same fitment but differ in details such as speed rating, weight, and stated load capacity. In 245/45R18, for example, the Comp 2 A/S is a 96W tire weighing 28 pounds, while the Phenom T/A is a 100Y tire weighing 25.95 pounds with a 1,764-pound load capacity at 50 psi. In 245/40R19, the Comp 2 A/S is 94W at 28 pounds, while the Phenom T/A is 98Y at 28 pounds with a 1,653-pound load capacity at 50 psi.

Those differences matter most when you are comparing higher-speed capability and load-rating headroom within the same size, not when deciding basic fitment. Both series remain correct only if the size itself matches your G35 or Q45. If you are choosing between them, compare the exact version available in your size rather than assuming the same spec pattern carries across the whole g-Force family.

Rim-width requirements for 2005 Infiniti tires vary by size. The 17-inch sizes span from 6.0 to 7.5 inches for 215/55R17, 6.0 to 8.0 inches for 225/50R17 and 225/55R17, and 6.5 to 8.5 inches for 235/50R17. The 18-inch sizes run 7.0 to 8.5 inches for 225/45R18, 7.5 to 9.0 inches for 235/45R18 and 245/45R18, and the 19-inch sizes step up to 7.5 to 9.0 inches for 225/40R19 and 8.0 to 9.5 inches for 245/40R19.

That range is why wheel diameter alone is not enough when replacing tires on a 2005 Infiniti. A size may fit the same diameter wheel but still call for a wider rim than another size in the same family. If the car has aftermarket wheels or a staggered G35 setup, compare the actual wheel width against the tire’s approved range before finalizing the selection. That check is especially important on the 18- and 19-inch performance fitments.

The 2005 Infiniti tire range here is made up of modern radial products without tube-type markings, so these fitments are treated as tubeless radial applications. The size strings use modern radial coding and do not carry TT markings that would indicate a tube-type design. That applies across the G35 and Q45 sizes in this range, from the 17-inch fitments through the 19-inch G35 packages.

In practice, tube use is not the normal starting point on a 2005 Infiniti unless a wheel condition issue or unusual custom application creates a separate reason to discuss it. What matters more is the condition of the wheel, the valve stem, and the bead seat on a car now approaching collector age. If the car has original wheels that have seen years of use, a careful inspection of the wheel surfaces is just as important as choosing the correct tire size.

A 2005 Infiniti should be stored in a cool, dry space away from direct sunlight, electric motors, welders, furnaces, and other ozone-producing equipment that can age the sidewalls. Keep the tires clean, maintain proper inflation, and move the car periodically so one section of the tread is not carrying the load for months at a time. Modern radials resist flat-spotting better than older bias-ply tires, but long static storage still hardens rubber and can mark the tire’s contact patch.

For a G35 or Q45 that only comes out occasionally, storage habits often affect tire condition more than mileage does. If the car will sit for an extended period, many owners slightly overinflate within safe limits for storage and then reset pressure before driving, or use cradles or stands to reduce sustained load. The goal is to protect the tire from environmental aging and long-term deformation, not simply to keep it off the floor.

On a 2005 Infiniti, tire age is usually a more important limit than tread wear, especially on low-mile collector or weekend-driven cars. A practical rule is to begin evaluating tires closely once they are around five to seven years old and to treat about ten years from the DOT date code as a serious replacement point even if tread remains. Performance-oriented radial tires can still look usable while the rubber compound and internal structure are aging.

That matters on both the G35 and Q45 because many of these cars now live second or third lives with lower annual mileage than when new. A tire that has plenty of tread but is old, heat-cycled, or cracked is not a strong candidate for continued use on a fast modern sedan. Reading the DOT date code and matching it against how the car is actually driven will tell you more than tread depth alone.

Tires on a 2005 Infiniti should be inspected before every drive and given a more thorough once-over before any extended highway trip. Check for sidewall cracking, cuts, bulges, punctures, uneven tread wear, and air-pressure loss, and make sure the valve stems are still pliable and sealing well. On staggered G35 setups, compare both front and rear tires closely because the sizes and loads are not the same.

Frequent inspection is especially important on a car that alternates between long storage periods and occasional spirited use. A Q45 or G35 can feel normal right up until an aging tire starts to separate, vibrate, or lose pressure. Looking over the spare at the same time is smart as well, since an old or mismatched spare can turn a simple roadside issue into a more complicated trip interruption.

A 2005 Infiniti G35 would have originally used modern radial tires, not bias-ply construction, and the correct size depended on the exact wheel package fitted to the car. Within the 2005 G35 range, those sizes include 215/55R17, 225/50R17, 235/50R17, 225/45R18, 235/45R18, 245/45R18, 225/40R19, and 245/40R19. The larger story is that Infiniti was using contemporary low-profile performance radials by this point, with size changing according to trim and wheel specification rather than a single universal fitment.

For an accurate restoration or preservation-minded replacement, match the tire size to the actual wheel package on your individual G35 first. The exact original tire brand can vary by market and equipment package, so the safest path is to verify the factory placard, original literature, or marque-community references for your specific car. Once the size is confirmed, the closest authentic look will usually come from staying with a blackwall radial in the correct dimensions.

Yes, correct tire fitment matters when showing a 2005 Infiniti, even though the car is modern enough that judges may focus more on overall correctness than on vintage-sidewall details. The main points are the proper size, the proper wheel diameter, and an appearance that suits the car’s original character. A G35 wearing the wrong profile or an oversized aftermarket fitment can look obviously off, and a Q45 can lose its factory luxury presence if the proportions are incorrect.

For a judged car, the safest approach is to keep the exact size family that belongs to the model and wheel package, then choose a sidewall style that matches how the car would have appeared in period. Blackwall radials are the natural choice for most 2005 Infiniti restorations. If you are building to a specific event standard, consult Infiniti marque groups or the event’s judging guidelines so the tire choice supports the rest of the car’s presentation.

Where both are offered for a 2005 Infiniti, BFGoodrich g-Force Comp 2 A/S and Nitto NT555 G2 share the same basic size but differ in weight, load rating, and approved rim-width presentation. In 225/50R17, the BFGoodrich g-Force Comp 2 A/S weighs 27 pounds with a 6.0 to 8.0 inch rim-width range, while the Nitto NT555 G2 weighs 25.51 pounds, carries a 1,653-pound load capacity at 50 psi, and fits a 6.0 to 8.0 inch range. In 245/45R18, the BFGoodrich version is 96W at 28 pounds, while the Nitto is 100W at 27.37 pounds with a 1,764-pound load capacity at 50 psi.

That comparison is useful when you already know the exact size and want to compare two modern radial personalities inside the same fitment. It is less about authenticity than about selecting the tire whose specs best suit how the car will be used. On a preserved but regularly driven G35, those small differences can matter more than brand familiarity alone, especially when the car already has aftermarket or sport-package wheels.

Yes, the available 2005 Infiniti tires are modern radial designs intended for normal road use, and the speed ratings in this range support highway operation comfortably when the tires are in good condition. Most sizes carry a W rating, which corresponds to 112 mph, while some BFGoodrich Phenom T/A versions in 245/45R18 and 245/40R19 carry a Y rating to 186 mph. Those numbers exceed ordinary highway speeds by a wide margin, and on a 2005 Infiniti the car’s maintenance condition, alignment, suspension, and braking health usually matter more in real-world safety than the raw speed letter alone.

The key is remembering that a speed rating is not permission to drive at that number. It is a performance standard under controlled conditions with a properly loaded, correctly inflated, undamaged tire. For a G35 or Q45 headed onto the highway, age, inflation, wheel condition, and matching the right tire size to the car are more important than choosing the highest rating available. A fresh, properly fitted W-rated tire is far safer than an old, cracked Y-rated one.

Inflation pressure on a 2005 Infiniti should follow the vehicle’s factory placard or owner’s manual for normal service, while the tire’s own maximum pressure figure should be understood as part of its load specification rather than as the everyday setting. Some sizes here include load-and-pressure references such as 1,521 pounds at 50 psi for 225/45R18, 1,764 pounds at 50 psi for certain 245/45R18 products, 1,653 pounds at 50 psi for some 245/40R19 products, and 1,819 pounds at 50 psi for one 225/55R17 option.

Those numbers should not be transferred from one size to another or used as a blanket pressure target for every G35 or Q45. The correct operating pressure depends on the car, axle load, and the exact size fitted. If your Infiniti still has its original placard, use that as the baseline and then confirm the tire is carrying adequate load within its rated range. Pressure should always be checked cold, not after driving.

Before taking a 2005 Infiniti on a longer drive, inspect each tire for cracking, cuts, bulges, nails, uneven wear, and proper cold inflation, and make sure the spare is usable. Look closely at the inside sidewall as well as the outer face, because age damage can hide where it is harder to see. On a G35 with staggered 19-inch fitment, confirm that the front and rear sizes are in their correct positions and that no mismatched substitute has been installed.

Tires are only one part of the pre-trip check, but they are the part touching the road. A long drive in a Q45 or G35 also deserves a quick review of brakes, fluid levels, battery condition, and suspension feel, especially if the car has been sitting. If the tires are more than a few years old, have any visible cracking, or show unusual wear patterns, resolve that before the trip rather than assuming they will be fine for one more outing.