Are you planning to upgrade the tires of your Jeep Grand Cherokee, and you’re wondering how big of a tire you could put in? Wonder no more, for we have researched this question, and we have the answer for you.
The biggest recommended tires for Jeep Grand Cherokee are 245/65R17 and 245/70R16 without needing to change anything else in your Jeep.
Learn more about the different types of tires and their relationship to your Jeep Grand Cherokee in the succeeding sections. Read on!
What are the biggest tires for a stock Jeep Grand Cherokee?
These size 245/70R16 tires by Pirelli are great for regular road driving, but you might experience some rubbing when you drive your Jeep Grand Cherokee offroad. Jeep Grand Cherokee is notorious for having small wheel wells. Thus, anything that is larger than 29-inch tires has the potential to rub when driving offroad.
The Pirelli Scorpion street radial tire 245/70R16 is available on Amazon. Check it out through this link.
Driving offroad causes your suspension to move a lot and has a high likeliness of getting to the bottom compared to city driving. This causes your tires to move closer to the wheel well, even rub or slam against it when driving on really rough roads.
How to read tire sizes?
The size of a tire is always presented in three different numbers. The first two numbers are separated by a slash mark, while the last two numbers are separated by a letter. Always remember that the first number is in millimeters, the second number is a percentage, and the last number is in inches.
The first number of the tire size is the width of the tire. Take note that this is measured in millimeters.
Some tires have a letter that comes before the tire width. This letter can either be a “P,” “LT,” or “ST.” If there is no letter before this number, that means the tire is a metric tire or a European size tire.
A “P” before the tire width means that the tire was made as a passenger-class tire. This type of tire is ideal for use with cars, crossovers, SUVs, small pickup trucks, and even minivans.
The mark “LT” that could appear before the width means that the tire was made for light trucks that can haul heavy cargo or tow trailers. This type of tire is suitable for vehicles that require extra heavy-duty tires.
This type of tire is suitable for three-quarter-ton trucks or 1-ton trucks. They can also be used on SUVs that are often used offroad.
This marking means Special Trailer. These tires are suitable for use on trailers. This includes fifth wheels, boat trailers, travel trailers, and utility trailers.
The second number appears after the slash mark. This number represents the aspect ratio of the tire. An aspect ratio is a percentage number that represents the height of the tire's sidewall.
The height is represented as a percentage of the width of the tire. Thus, a 245/65R17 tire means that it has a sidewall height that is 65% of the width—which is 245. This gives us a sidewall height of 159.25 millimeters or 6.27 inches.
The height of the sidewall goes up as the ratio goes up. Some people also call the sidewall height the section width.
The letter that separates the last two numbers represents how the tire was made.
An “R” means that the tire was made following the radial method. This is the current industry standard for tire assembly. Tires that are made through this method provide better grip, better ride comfort, and help provide better gas mileage.
The layers of a radial tire are arranged perpendicular to the direction of travel.
A letter “D” between the last two numbers means that the tire was made using the bias method. The layers of these tires are diagonally arranged to the direction of travel.
This method is commonly used with motorcycle tires and some trailer tires.
The last number tells you the diameter of the wheel or rim that the tire will fit into. This is measured in inches.
Will 31-inch tires fit on a stock Jeep Grand Cherokee?
They will fit on a stock Jeep Grand Cherokee. However, you will experience rubbing—especially when you are at your maximum turning angle. The tires can also rub when you drive your Jeep Grand Cherokee offroad or when you hit some deep potholes.
Can you fit 33s on a Grand Cherokee?
You can, but not on stock.
To fit 33s on your Jeep Grand Cherokee, you will need to lift it by at least three inches. Then you will need to trim some of the fenders. This will give your Jeep Grand Cherokee the wheel well size that can accommodate 33-inch tires.
What tires will fit my Jeep Grand Cherokee?
The common tire sizes for Jeep Grand Cherokee are the following:
- 245/70R17 – for those that came with factory 17-inch rims
- 265/60R18 – for those that came with factory 18-inch rims
- 265/50R20 – for those that came with factory 20-inch rims
- 295/45R20 – for those that came with factory 20-inch rims
How tall is a 295 tire?
A 295/45R20 tire, like the one in the previous section, is 32.5 inches tall. It has a width of 11.6 inches and a wheel diameter of 20 inches.
What is the offset of stock Jeep wheels?
The 2021 Jeep Grand Cherokee has a positive offset that depends on the rim diameter and width. The list below summarizes this.
Keep in mind that tire offset measurements are always in millimeters.
- 2021 Jeep Grand Cherokee with a rim diameter of 17, 18, and 20 inches and rim width of 8 inches has a positive offset of 56.4.
- 2021 Jeep Grand Cherokee with a rim diameter of 19 inches and rim width of 8 inches has a positive offset of 55.
- 2021 Jeep Grand Cherokee with a rim diameter of 20 inches and rim width of 8.5 inches has a positive offset of 50.
- 2021 Jeep Grand Cherokee with a rim diameter of 20 inches and rim width of 10 inches has a positive offset of 50.
- 2021 Jeep Grand Cherokee with a rim diameter of 22 inches and rim width of 11 inches has a positive offset of 40.
- 2021 Jeep Grand Cherokee with a rim diameter of 21 inches and rim width of 10.5 inches has a positive offset of 45.
- 2021 Jeep Grand Cherokee with a rim diameter of 21 inches and rim width of 9 inches has a positive offset of 50.
What is tire offset?
The offset of a tire represents how far the mounting surface is from the center of the tire. The mounting surface is where you bolt the rim. Imagine your tire being divided by an imaginary plane into two along its width. The imaginary dividing plane is parallel to the length of the car.
This imaginary division gives you one half of the tire that is closer to the engine, which is the inner half, and another half that is closer to the curb, which is the outer half. A positive offset means that the mounting surface is within the outer half of the tire. This moves the tire a little towards the inside of the wheel well.
A negative offset, on the other hand, means that the mounting surface is within the inner half of the tire. This offset moves that tire towards the outside of the wheel well.
An offset of zero means that the mounting surface is aligned with the center of the tire.
Knowing the offset is important if you’re installing wider tires than the factory-installed tires. This will allow you to adjust the offset accordingly to match the width of the tires.
How much bigger can you go on tire size?
Keep in mind that your speedometer measures your speed based on the wheels' number of rotations. If you replace your tire size with a much larger one, the speedometer reading will become inaccurate.
If you want to move bigger tires with minimal impact on the accuracy of your speedometer, keep the tire size to within 3% of the diameter of the factory-installed tire.
Make the same computation when you replace your rims. The total tire diameter is the combined measurement of your tire and rims. Going for bigger rims means that you need to have a tire that has a lower sidewall height so that the total will be within 3% of your original tire size.
However, if you’re willing to adjust gear ratio, speedometer, and tire pressure data, then you can go to a tire size that is bigger than 3% of your original tire.
The Jeep Grand Cherokee can handle tires that are larger than the recommended sizes. However, there are minor modifications that should be done on the Jeep Grand Cherokee to prevent tire rubbing.
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