Nitto NT421Q . FEATURES AND BENEFITS: All weather traction; Hydroplaning resistance; Enhanced controllability; Improved cornering ability; Maintenance Indicators; . OVERVIEW: The Nitto NT421Q is a performance and high performance, all season tire manufactured for SUVs. Nitto offers a 60,000 mile treadwear warranty with the W speed rated sizes and a 75,000 mile treadwear warranty with the H and V speed rated sizes of this tire model.The asymmetric tread pattern features a 3D multi-wave interlocking siping detail which ensures excellent dry, wet and winter weather road gripping ability. The tire performs especially well in winter weather as well, thanks to the large, open grooves of the inner shoulder and the high density siping design that promotes additional biting edges. The three wide circumferential grooves avoid hydroplaning in dangerous situations by channeling water and slush away from the tire footprint. This ensures a more secure year round driving experience.The special tread design and the extra strength layer boosts the tire's handling and controllability. The tire's internal structure features added circumferential rubber shoulder inserts that provide an additional layer of strength to the tire. This ensures an increased road contact in all weather conditions which enhances the steering responsiveness and driving stability. As a result, the tire is quick and precise in its steering response and is stabilized during the drive to allow it to be easier to navigate. The tread design's outer shoulder design promotes an increased number of biting edges that firmly grip the road during cornering situations. They maintain road contact and boost the cornering and maneuvering ability and power. This promotes excellent controllability all year.The NT421Q's special tread pattern also extends the tire's usability and tread life. The tread design evenly spreads the driving pressure out across the entire tread area to prevent irregular wear patterns from forming. Uneven tread wear is also combated by the tire's Maintenance Indicators. These are located on the walls of the circumferential grooves and they provide a visual monitor of the tread wear rate and alert the driver of wear issues. The driver can easily notice when the tire is wearing irregularly, simply by checking the Maintenance Indicators. Manufacturers recommend changing tires every 10 years. As long as tires are properly stored before they are sold, the year of their manufacture will not shorten their service life.