Trucks are used to tackling rugged terrain and off-road travel. Having the correct tire size for trucks is critical as that improves ride quality, braking performance, cabin comfort, fuel efficiency, handling, steering directness, and other factors. However, reading and selecting options can get confusing due to the varied aspects involved in a tire’s overall size. Here are the factors to consider while zeroing in on the sizes of tires for trucks:
Having the right-sized tire allows trucks to have excellent traction and stability on the road. If the tires fitted onto a truck are smaller or bigger, there is an increased risk of accidents or poor ride quality.
One of the chief components of tire sizes is tire width. One can identify tire sizes by the unique code number written on them. For example, if the number is P225/70R16 91S, then the width of the tire is 225 mm (“P” stands for “passenger vehicle,” “LT” for “Light Truck Tire,” and “ST” for “Special Trailer”).
If truck owners want their vehicles to have good road grip and cornering ability, they can select wider tires. Wider tires than the one the truck comes with are factory-fitted and positively affect the ride stability. However, one must only go for truck tires that are just the right height. Such tires can increase friction and rolling resistance and, as a result, reduce the vehicle’s fuel efficiency. Also, broader and heavier tires make the steering feel heavy and less stable.
Tire width also needs to change depending on other factors. For example, narrower tires can provide some good traction on snow during winter, but stability issues will arise again if one goes too narrow.
Similarly, it makes sense for truckers to go for broader truck tires if their vehicle has immense horsepower and torque. In such cases, the wider tire will provide better acceleration and reduced dangerous wheelspin.
All these size-measuring components, such as tire height, width, and others, are relative to the measurements of the factory-fitted tires that come with trucks that owners purchase from their local dealerships.
Taller tires are the ideal choice for increasing the ground clearance of a truck. As a result, selecting such tires means that trucks will not have scraped underbellies even when their owners drive them over rough, undulated, and unforgiving terrain.
However, the boosted ground clearance comes at the vehicle’s overall handling cost. For example, taller truck tires translate into increased body roll while cornering.
Additionally, if the tires are too tall or wide, there will be rubbing on the inside of the truck’s wheels, resulting in the frequent wearing of both the tires and wheels.
In P225/70R16 91S, the 16 denotes the wheel diameter of the tire in inches. As the name implies, wheel diameter is the measurement of the alloy or steel wheel fitted inside the truck tires. The wheel diameter is critical as it also influences the tire thickness.
Larger wheels will need larger tires. Using more extensive and taller tires, as seen above, will negatively affect the ride and handling of a truck. Therefore, one needs to be careful while selecting wheels. Wheel diameter is a valuable metric for tire buyers as it enables them to select just the right size of tires for their vehicle.
The number right next to the slash in P225/70R16 91S is the aspect ratio of truck tires. The aspect ratio indicates the overall profile of truck tires. Usually, this number is denoted in percentages. To calculate the aspect ratio, tire makers divide a tire’s height (from its wheel rim) by width. So, the aspect ratio of 70 percent in the above numerical example translates into the tire’s height being 70 percent of its overall width.
Tires with a lower aspect ratio, say, 60 percent or lower, offer better handling and road grip than higher ratio tires. In return, the ride quality of lower-ratio tires is worse than those with higher aspect ratios.
The letter next to the aspect ratio in P225/70R16 91S is the construction type of the tire. These generally have two classifications – R for radial and D for diagonal. Now, radial tires are among the most used ones across the country. These tires have their internal ply cords oriented in a radial direction, meaning that they are at a 90-degree angle to the direction of rotation of the tire.
While selecting tires, one must select these as they offer higher road grip, better mileage, greater ride comfort, higher reliability and durability, and lower rolling resistance.
The speed rating indicates the capability of a tire at a particular speed based on the lab tests run by tire makers. In the example, the speed rating is the last number accompanied by the letter S. A vehicle with a speed rating of 120 can cruise at that speed in their truck without the fear of damaging the tire. The higher the speed at which one regularly drives their vehicle, the greater the speed rating should be for their tires.
By carefully considering these listed elements before buying tires, owners can ensure that the tire sizes are perfect for their specific trucking requirements.