FONTANA, Calif. (May 19, 2003)—Kumho Tire USA will soon make available a 26-inch size of its ECSTA STX light truck tire, the Fontana-based tire maker said.
Kumho displayed the tire—along with a prototype 28-inch version—at the 2002 Specialty Equipment Market Association/International Tire Expo show in November. The ECSTA STX previously had been available in sizes from 15 to 24 inches, Kumho said. The new 26-inch tire, size 305/30R26 110V, is designed to fit vehicles such as the Cadillac Escalade and Ford Expedition.
“Tuners are increasingly customizing vehicles like the Cadillac Escalade and Ford Expedition,” said Rick Brennan, Kumho's high performance brand manager. “So if a mid-size sedan can wear a 20-inch wheel and tire package, a large SUV can wear an even bigger wheel and tire to achieve the same look.”
The STX now is available in 22 sizes. The tire has a directional tread pattern, full-depth circumferential grooves and a center-to-shoulder groove to remove water from the footprint. Large tread blocks also enhance footing and handling, Kumho claimed.
Kumho also issued a technical service bulletin with the tire, warning that the 26-inch tire has a rated maximum load capacity of 2,337 pounds at 42 psi (cold) of air pressure, with a maximum inflation pressure of 50 psi (cold) allowed with no increase in load-carrying capacity. When the tire is mounted on a light truck, the maximum load capacity must be reduced by dividing the maximum load capacity shown on the sidewall by 1.1. On a light truck, the maximum load of the tire is 2,124 pounds at 42 psi (cold), Kumho said.
Kumho emphasized that the 305/30R26 110V STX should not be mounted on a vehicle where the load exceeds the maximum load capacity of the tire, or 2,124 pounds.
To determine the maximum load capacity of a light truck, Kumho said dealers should use the following steps:
Determine the gross axle weight rating (GAWR) of the vehicle. This information should be on the vehicle's certification label in the glove box or end of the driver's door.
Divide the GAWR by 2. This gives the maximum load per tire.
Determine the maximum load as marked on the sidewall of the tire. For passenger tires used on light trucks, the maximum load listed on the sidewall must be reduced by dividing by 1.1.
Compare the load calculated in Step 3 to the load calculated in Step 2.
The tire load calculated in Step 3 must exceed the axle load calculated in Step 2. If the tire load capacity in Step 3 is lower than the axle load in Step 2, the tire cannot be used on that vehicle.