Tire maintenance & safety

Tire rain grooves: Overview & maintenance

Last updated 10/17/2022 - Originally published 9/23/2020
Written by SimpleTire

Tire design has become incredibly specialized since the development of the radial tire. There are tires that are engineered, designed, and tested to be effective for a variety of driving surfaces, as well as different driving conditions. Mud and snow tires, off-road tires, touring tires, high-performance tires, all-season tires, winter tires: all of these examples possess unique attributes within their component make-up, from tread design to rubber compound.

One example of tire design that can vary from tire to tire is a tread pattern with a special groove that's engineered to quickly and continuously siphon and channel water away from the tire's contact patch. This groove is known as a rain groove.

How Does a Rain Groove Work?

As a tire rolls, the area that comes in contact with the ground is known as the contact patch. In order for a vehicle to travel safely, this contact patch should remain in contact with the road surface at all times. Because of this, the portion of a tire that's touching the road at a given moment is made to flatten and increase in size and then spring back into its rounded shape as the tire continues to roll. On well-maintained, dry road surfaces, it's not difficult for all of the contact patch to remain touching the road surface.

When variables such as rain are added to the equation, however, maintaining this contact with the road surface becomes more difficult. When there are large areas of collected water, a tire might lose total contact with the road and hydroplane. Hydroplaning is the cause of many automobile accidents annually, and they often involve multiple vehicles.

Simply put, the rain groove pulls water away from the parts of the tire that give it traction. To combat water on the roadway and lower the risk of hydroplaning, tires possess rain grooves. The rain groove was introduced in the late 20th century, greatly enhancing tread groove patterns. Running down the center of a tire, a rain groove works with angled tread patterns and tread voids. This allows road moisture the path of least resistance in escaping from under the contact patch.

Are Rain Grooves Necessary?

For drivers who live in temperate climates or regions that receive a significant amount of rain throughout the year, tires with rain grooves can significantly increase driving safety. For those living in dry areas, rain grooves aren't as crucial. Still, don't discount them. You may want to consider purchasing tires with rain grooves because they don't hurt your vehicle's performance in dry weather. These tires are manufactured to perform on both wet and dry pavement yet boast the added safety advantage of rain groove technology.

Maintenance for Rain Groove Tires

Regular and routine maintenance is necessary for tires with rain grooves. General inspection, including a simple visual inspection and checking the tire inflation pressure, will aid in avoiding many issues. Routine tire rotations should also be performed every 5,000 - 6,000 miles. It's crucial to maintain evenly worn tread on these specialty tires. Improper inflation can lead to warped tread wear, ultimately ruining the capability of the rain groove. If well-maintained, rain groove tires (such as Goodyear AquatTred) are capable of adding wet driving safety to your vehicle for a long time.

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