Will 255 70r18 Fit Jeep Grand Cherokee
Choosing new tires for your Jeep Grand Cherokee can be confusing. You might wonder if a 255 70R18 tire will fit your vehicle without problems.
Tire size affects safety, comfort, and performance, so picking the right one matters. This article explains everything you need to know about the 255 70R18 size and if it’s a good fit for your Grand Cherokee.
You’ll learn about compatibility, possible issues, and what to expect when upgrading your tires. Whether you drive mainly in the city or love weekend off-road trips, understanding tire fitment is key to making a confident decision.
Understanding 255 70r18 Tire Size
The 255 70R18 tire size means:
- 255 mm width
- 70% aspect ratio (sidewall height is 70% of width)
- R stands for radial construction
- 18-inch wheel diameter
This is a popular size for SUVs and trucks. The overall diameter is about 32.1 inches (816 mm), which is bigger than many stock Jeep Grand Cherokee tires. A taller tire means more rubber between your wheel and the road, which can help absorb bumps and protect the rim. The larger sidewall also helps when driving over rocks or uneven terrain, making it a favorite for off-road fans. However, this extra height can also change how your Jeep handles, especially at higher speeds or during sharp turns.
Stock Jeep Grand Cherokee Tire Sizes
Most Grand Cherokees come with tire sizes like:
- 245 65R17 (about 29.5 inches diameter)
- 265 60R18 (about 30.5 inches diameter)
- 265 50R20 (about 30.4 inches diameter)
Compared to these, the 255 70R18 is taller and slightly narrower than the 265 width. This difference impacts ground clearance, speedometer reading, and fit. A taller tire can help you clear curbs, rocks, and snow, but it also takes up more space in the wheel well. If your Jeep has the 20-inch wheels, keep in mind that swapping to 18-inch wheels with 255 70R18 tires will give you more sidewall but will require new rims.
Here’s a quick look at the differences:
| Tire Size | Width (mm) | Diameter (inches) | Aspect Ratio | Wheel Size (inches) |
|---|---|---|---|---|
| 245 65R17 | 245 | 29.5 | 65 | 17 |
| 265 60R18 | 265 | 30.5 | 60 | 18 |
| 255 70R18 | 255 | 32.1 | 70 | 18 |
Even a small increase in tire diameter can change how your Jeep looks and feels. For example, a 2-inch jump in tire height noticeably lifts your Jeep, which some owners like for a more rugged look.
Will 255 70r18 Fit Your Grand Cherokee?
Installing 255 70R18 tires is possible, but there are key points to check:
- Wheel Clearance: The tire’s taller profile may rub against the wheel wells, especially during turns or when driving over bumps. If you drive with a full load or tow a trailer, the suspension compresses more, increasing rubbing risk.
- Suspension: If your Grand Cherokee has a stock suspension, the fit is tight. With aftermarket lift kits (2-inch or more), it’s safer. Some trims with air suspension may have slightly more space, but always check with the suspension at its lowest setting.
- Offset & Rim Width: The right rim width (7–9 inches) and proper offset help the tire fit without sticking out or rubbing. A rim that’s too wide or too narrow can change how the tire sits and how much it sticks out from the fender.
- Speedometer Accuracy: The bigger diameter makes the speedometer show a slower speed than actual. This affects odometer readings, so your actual mileage will be a bit higher than what you see.
Real-life Example
Many Jeep owners on forums and groups have tried this size. Most report no major issues if their vehicle has a mild lift.
On stock suspension, rubbing may occur on the front bumper or fender liner. One Grand Cherokee owner shared that with stock ride height, the tires only rubbed when turning fully while reversing up a driveway.
After installing a 2-inch lift kit, the rubbing stopped completely. Others found that trimming a small area of the fender liner or moving a pinch seam slightly solved the problem.
Pros And Cons Of 255 70r18 Tires
Pros:
- More ground clearance: Good for off-roading and helps avoid scraping the underbody on rough roads or rocks.
- Better traction: Wider footprint helps grip, which is useful on loose gravel, sand, or mud.
- Improved appearance: Aggressive look that many Jeep owners love. The taller tires fill out the wheel wells, giving a more powerful stance.
Cons:
- Possible rubbing: May need trimming of fender liners, especially if you drive off-road or have a full cargo load.
- Speedometer error: Shows less speed, which can be confusing if you’re not aware of the change.
- Heavier tire: Slight drop in fuel efficiency, and the extra weight can make the steering feel a bit heavier, especially at low speeds. You might also notice a small decrease in acceleration.
A less obvious downside is that some automatic parking systems or driver-assist features rely on factory tire size. Changing tire size can sometimes affect their accuracy.
What To Check Before Buying
- Measure wheel wells: Check the space above and behind the tire. Use a tape measure to see how much room you really have—don’t just guess.
- Check rim size: Make sure your wheels are 18-inch and can handle 255 mm width. If you currently have 20-inch wheels, you will need to buy new 18-inch rims.
- Suspension type: Is your Jeep lifted? If not, expect possible rubbing, especially if you drive on rough roads.
- Driving style: Off-roaders benefit more from bigger tires, while city drivers may prefer the comfort and quiet of stock sizes. If you mostly drive highways, the extra tire height may add more road noise.
Also, check your spare tire. If you upgrade to 255 70R18, your spare should match, or you risk problems in an emergency.
Here’s how the change might affect your Jeep:
| Factor | Stock Jeep | With Lift Kit | 255 70R18 Impact |
|---|---|---|---|
| Ground Clearance | Standard | Higher | +1.6 inches approx. |
| Rubbing Risk | Medium | Low | Possible, needs check |
| Fuel Economy | Normal | Normal | -1 to -2 mpg |
Non-obvious Insights
- Tire Pressure Matters: Using the right tire pressure prevents uneven wear and keeps handling safe. Higher-profile tires often need slightly lower pressure than stock. For example, if your original tires run at 36 psi, you might want to use 32–34 psi with the new size, but always follow the tire manufacturer’s recommendations.
- Insurance and Warranty: Some insurance companies might not cover damages from tire modifications. Always check before changing tire size. Also, some tire shops refuse warranty claims if the tires are not the size recommended for your vehicle.
Another detail: Larger tires can sometimes interfere with brake cooling, especially on long downhill drives. Make sure your brakes are in top condition after upgrading.
Common Mistakes To Avoid
- Ignoring rim offset: Wrong offset causes the tire to stick out or rub, and can make your Jeep illegal in some areas.
- Skipping test fit: Always test one tire before installing all four. Drive over some bumps and turn the steering fully to check for rubbing.
- Assuming all Grand Cherokees are the same: Different model years and trims may have different clearances. For example, Trailhawk models often have more space than Limited or Laredo trims.
Another mistake is forgetting to recalibrate your speedometer. Many mechanics can do this for a small fee, and it helps keep your readings accurate.
Expert Guidance
If you plan to use 255 70R18 tires, talk to a tire shop or Jeep specialist. They can check your Jeep’s suspension, rim specs, and wheel well space. Sometimes, a small lift kit (2 inches) solves most fitting issues. Also, consider trimming fender liners if minor rubbing occurs. A professional can do this neatly, so you keep a factory look and avoid damaging important parts behind the liner.
If you tow heavy loads, ask about the effect of taller tires on towing stability. Sometimes, a larger tire can affect how a trailer handles, especially in crosswinds.
For more technical data, you can check the official Jeep specifications or visit Tire Rack for detailed tire fitment guides.
Frequently Asked Questions
Will 255 70r18 Fit A Stock Jeep Grand Cherokee?
Most stock Grand Cherokees can fit this size, but expect tight clearance. Minor rubbing may happen, especially off-road or when turning sharply.
Owners with air suspension should check at the lowest ride height.
Do I Need A Lift Kit For 255 70r18 Tires?
A lift kit is recommended for trouble-free fit. With a 2-inch lift, the tires fit easily and avoid rubbing.
If you only drive on highways, you might get by without a lift, but it’s always best to check.
How Will My Speedometer Change?
The speedometer will show a slower speed. For example, when driving at 60 mph, the actual speed may be closer to 63 mph.
GPS apps can help check your true speed.
Will Bigger Tires Affect Gas Mileage?
Yes, bigger and heavier tires like 255 70R18 can reduce fuel efficiency by 1–2 mpg. Keep an eye on tire pressure to help reduce the impact.
Can I Use 255 70r18 Tires Off-road?
Absolutely. This size gives more ground clearance and better grip, making it ideal for off-road adventures.
However, always check tire pressure before hitting the trails for best performance.
Choosing the right tire size is important for your Jeep Grand Cherokee’s safety and performance. The 255 70R18 tire fits most models, but double-check your suspension, rim specs, and wheel well clearance. With proper planning, you can enjoy better off-road capability and a bolder look. Always consult a specialist before making changes, and enjoy your Jeep’s new style and performance. Don’t rush the decision—taking time to measure and get advice helps you avoid problems and get the most from your upgrade.
