One of the first things that beginner off-roaders notice about four wheeling trucks is the huge tires. Big tires are impressive. The bigger, the better, right? Those giant donuts definitely make a statement when they’re driving down the highway, that’s for sure!
There’s a thing about big tires though, that experienced off-roaders know. As does happen, this is one of those cases where bigger isn’t necessarily better, unless there’s a use for those bigger tires. Most importantly, when there is a need for bigger tires, sometimes other things have to change to account for them. So, while giant, knobby off road tires may look impressive on your truck, unless all angles are considered and necessary modifications done, off-roaders are likely to end up severely disappointed and maybe even wind up with a damaged vehicle.
Tire Size and Body Modifications
Every truck is designed to fit a certain size tire under the wheel wells. While 4x4 offroad vehicles used for extreme conditions usually accept a much wider range of tire size, sometimes a tire can just be too big for the truck. When this happens, if those big knobbys are really necessary, it means some minor or major truck mods. The reason for this is because taller tires with a larger circumference will rub in the wheel well against the bumper and other parts of the truck because they are just too big for the space.
This can become especially problematic while driving if the tires bottom out in the wheel well or there is a rubbing or scraping sound when driving over rough terrain. Common mods that allow the use of bigger tires in these cases include taller, tougher shocks and struts, body lift kits, removal of mud flaps and the installation of stubby bumpers for some 4x4s like Jeeps.
Tire Size Affects Gearing
Another issue when increasing tire size is that it will commonly set the truck’s gearing off by decreasing the gear ratio. This can have both positive and negative effects. For starters, larger tires rotate fewer times, so the truck’s RPMs will be lower at any given speed.
This is better for the tire and the truck itself, since fewer revolutions means less wear and tear; however, the speed will be off, sometimes by quite a bit. This may not matter for some, but for those who drive their trucks on the street as well, it could mean a few tickets if you’re not paying attention to your actual speed!
Another option is to switch to lower gearing in the differential. Lower gear ratios also offer improved fuel efficiency, but less power, which could be another issue, also remedied by switching out the gears.
Tire Size Affects Ride
Naturally, bigger tires that require other modifications like lift kits, taller struts, and different gears are also going to affect the ride of the truck. Hopefully that isn't a surprise to anyone making these kinds of mods. Rides can be stiffer and big tires will behave completely different than smaller ones. There is definitely a learning curve involved when switching up to larger, taller tires on any truck.
All that said, for off-roaders willing to make the necessary modifications on their trucks, bigger tires can open up all sorts of possibilities in off-roading fun. The most important thing that any off-roader must understand is that there’s quite a difference between big tires for show and big tires that go. If you want to go, do the research, buy the right tires for your offroading truck, and if it’s necessary, be prepared to make a few other mods that go hand-in-hand with tall tires!