In the past few weeks, I have been on the hunt to find the best tires for a 1998 Jeep, hoping to make the vehicle better suited for off-roading. The main functions of a vehicle’s tires are to support the vehicle load, transmit traction and braking forces to the road surface, absorb road shocks, and change and maintain the direction of travel. However, if the vehicle plans on going off-road, tread, width, profile, rim size, and height come into play more than they would with simple on-the-road driving.
First off, there is tread. It is necessary to have good tread because it is the actual contact patch between your car and the ground. Tread is made up of raised rubber sections with space between them. In simple terms, a shorter tread block and less void between each creates the maximum contact patch on paved roads, while a taller tread with larger gaps between blocks will be conducive to grip onto dirt trails since the tires can bite into and conform around the terrain more. For the 1998 Jeep, it was important to have a taller, more aggressive tread for the off-road focus.
Tire width is a more important factor than I initially thought. In my mind, the wider the tire you can get, the better. Having wider tires allows for more traction on trails, plus I like the look of fat tires on cars. I was trying to find the widest possible tires within reason. I quickly learned, however, that the wider your tire goes, the less you are able to turn without the tread rubbing on the fender. This is important because, in cramped trails, you need a tight turning radius. Now, there are ways to fit a wider tire, such as cutting the fenders off the car to allow more room, but it gets to a point where it makes the car look bad. The tires this Jeep came with from the factory were a little less than 9” wide. The two widths it came down to were 10.5” and 12.5”. Initially, I was going to get the 12.5” tires. Still, they are more expensive, louder on the road, and tons of cutting would have to be done in order for them to fit as opposed to the 10.5” tire. The 10.5” still makes the tire significantly wider, without costing as much and only very minor fender cutting is needed.
The profile, rim size, and height work hand in hand with one other. When off-roading, it is important to have a large tire profile (which is the distance between the outer edge of the rim and the outer edge of the tire), so that the tire has room to manipulate the surface and gain traction. Two elements that determine this are rim size and height. The smaller the rim, the more distance the tire has to work with. I was able to find a very cheap set of 15” rims, so I decided to go with those. The height of the tires from the factory were about 28,” so an increase in size would give it more ground clearance and an aggressive look.
The final two options to choose between were 31” and 33” wheels. Both of these sizes would give an 8-8.5” tire profile, which would be more than enough. The ground clearance increase would be 1.5” with the 31’s and 2.5” with the 33’s. Similar to the width, the 33’s were more expensive, and a good amount of cutting would be necessary for them to fit. Even though the 31’s provide 1” less of ground clearance, they are cheaper and less fender cutting is needed.
As a result, I thought the 31×10.5R15 tires to d be best. This means a 31” tall tire which is 10.5” wide, that will mount on a 15” rim. These wheels have many different price points, most commonly in the $140-$280 range. I was able to find a set of BFGoodrich Mud-Terrain T/A’s for $210 apiece. These were highly rated tires that will last 60,000-80,000 miles, which is pretty good for off-road tires. The Mud-Terrains are safe on-road, as well as completely capable of handling mud and snow. Ultimately, I am really happy with the results of my purchases, and I am excited to keep taking the Jeep off-the-road.