What Tire Size Fits a Ford Explorer?

✅ The Short Answer

The single most reliable source for your exact vehicle is the tire-and-loading placard on the driver door jamb. It lists the factory tire size and the correct cold inflation pressure, usually 35 PSI front and rear. If the door sticker and what is mounted on the car do not match, someone changed the wheels, and you should figure out why before you buy a set.

Below we lay out the sizes by generation and trim, the math on overall diameter, and how far you can stretch before tires start rubbing the fender liner.

📏 Ford Explorer Tire Size by Trim and Year

Here are the common factory tire sizes for the fifth-generation (2011-2019) and sixth-generation (2020-present) Explorer. Optional wheel packages can shift these, so treat the table as a strong starting point, not gospel.

Notice that the 18-inch and 20-inch options land within a half inch of each other on overall diameter. That is by design, so the speedometer and the all-wheel-drive system read the same rolling distance regardless of which wheel you ordered. Keep new tires within roughly 3 percent of the factory diameter and your speedometer stays accurate.

🔬 Reading the Size: What 255/65R18 Means

Tire sizes look like a code, but each number is simple once you break it down. Using the base Explorer size 255/65R18 as the example:

• 255 is the tread width in millimeters across the tire.
• 65 is the aspect ratio, meaning the sidewall height is 65 percent of that 255 mm width.
• R means radial construction, which every modern passenger tire uses.
• 18 is the wheel diameter in inches the tire is built to fit.

You will also see a load index and speed rating after the size, such as 111H or 113T. Match or exceed the factory load index. The Explorer is a heavy crossover, often near 4,500 pounds curb weight, so a tire with too low a load rating is a real safety problem. If you see warning lights after a tire change, our guide on the TPMS light staying on covers the most common cause.

⬆️ The Biggest Tire You Can Fit

Owners ask this constantly, and the honest answer is that the Explorer is a unibody crossover, not a body-on-frame off-roader. There is limited room before the tire contacts the fender liner or strut at full lock. That said, you have a little headroom:

• On 18-inch wheels: Many owners run up to a 265/65R18 (about 31.6 in) or a 265/70R18 (about 32.6 in) on the Timberline-style setup without a lift. The 265/70R18 is the factory size on the off-road oriented Timberline trim.
• On 20-inch wheels: A 275/55R20 (about 31.9 in) is usually the practical ceiling on a stock truck.
• Beyond about 31.5 to 32 inches: Expect to trim the plastic liner, add a modest leveling spacer, or accept some rubbing on hard turns and bumps.

Going taller also changes your effective gearing and speedometer reading. A tire that is 4 percent larger makes the speedometer read about 3 mph slow at 70 mph and can dull throttle response on the four-cylinder EcoBoost models. If you notice odd shifting or a check engine light after a big tire change, run it through our free diagnosis before assuming the worst.

⚠️ Common Mistakes When Sizing Explorer Tires

Most fitment headaches come from a handful of avoidable errors:

1. Mixing tire sizes across the axles. The Explorer’s intelligent 4WD and all-wheel-drive systems hate mismatched rolling diameters. A difference of even 2/32 inch in tread depth across the axles can stress the power transfer unit. Always replace in full sets when you can.
2. Mounting a 20-inch tire on an 18-inch wheel. The size includes the wheel diameter for a reason. To go from 18s to 20s you need both new wheels and new tires.
3. Ignoring the door placard. A previous owner may have fitted a plus-size or off-size set. Trust the sticker and the AWD system’s needs over what happens to be bolted on.
4. Buying a lower load rating to save money. Cheaper tires sometimes carry a lighter load index. On a 4,500-pound SUV that is not the place to economize.
5. Forgetting the spare. The compact spare is a different size on purpose and is speed-limited to 50 mph. Do not run it long-term on an AWD Explorer or you risk drivetrain damage.

🧩 How to Pick the Right Replacement Size

Use this quick framework when it is time to buy:

• Staying stock? Read the door placard, buy that exact size, and match the load and speed rating. This is the safe default for 95 percent of owners.
• Want a smoother, quieter ride? If you have 21-inch ST or Platinum wheels and the ride feels harsh, the factory 18 or 20-inch wheel and a taller-sidewall tire from another trim will soften it, as long as you keep the overall diameter within 3 percent.
• Want a slightly more rugged look? Step up to a 265/65R18 all-terrain on 18-inch wheels. It is the lowest-risk way to add a little height and grip.
• Got a quote that feels high? Tire shops bundle mounting, balancing, valve stems, and disposal. Run the number through our quote checker to see if you are being overcharged.

If you are replacing tires because of uneven wear rather than age, that often points at alignment or suspension, not the tires. Read up on what uneven tire wear is telling you so you do not burn through a new set the same way.

❓ Frequently Asked Questions

📝 TL;DR

• Factory tire size for a Ford Explorer is 255/65R18 (base/XLT), 255/55R20 (XLT/Limited), or 275/45R21 (ST/Platinum).
• The 18-inch and 20-inch sizes share about a 31-inch diameter and are interchangeable with matching wheels.
• Bolt pattern is 5x114.3; cold inflation is typically 35 PSI per the door placard.
• Biggest practical fitment on a stock truck is roughly 265/65R18 or 275/55R20 (about 31.5 in) before rubbing.
• Always replace in matched sets to protect the AWD power transfer unit.