Large, powerful cars and SUVs with electric or hybrid drive are far heavier than conventional vehicles, yet offer little room to fit larger tires with higher load capacities. In response, Continental is now manufacturing the first passenger tire with the new “HL” load index. Inflated to the same pressure, these tires have a higher load capacity than those built to the former XL standard, said the company.
On the sidewall, products with the new maximum load capacity display the HL code ahead of the size, for example “HL 245/45 R 19 101 Y XL”. The load capacity of this HL tire stands at 1819 lb. / 825 kg (load index 101), which equates to a 10 percent increase over the familiar XL standard of 1653 lb. / 750 kg (load index 98). Passenger tires of this size built to the SL standard, adequate for many cars, up to and including mid-range models, can take a maximum load of 1477 lb. / 670 kg (load index 94). That makes the load capacity of the new HL tires almost 25 percent higher. Looking ahead, Continental is expecting to see growing demand for tires with the new HL code.
Increasing the load capacity while at the same time meeting customer requirements called for a number of changes in both the tire structure and the rubber compound.
“We were dealing here with tradeoffs that needed resolving at a very high level,” explains Dr. Stefan Habicht, head of the development project for these tires. “In terms of construction, we reinforced the bead and enhanced the contour of the tire to reduce tire/road noise. At the same time, we also optimized the pattern compound. As a result, we were able to achieve low rolling resistance, ensure precision handling and keep mileage at its customary high level.”
Continental is currently producing the first tires to the new HL standard for OE fitments, but they will also be available on the replacement market.