Henning Solberg marked Pirelli’s return to the top flight of the FIA World Rally Championship with a stage victory on Rally Sweden for the Sottozero Ice tire, which equipped a World Rally Car in competition for the first time since 2010.
And as well as demonstrating the pace of the Italian rubber by setting a string of top three times, Solberg underlined the durability of the Sottozero Ice tire by carrying just one spare in his Ford Fiesta RS WRC on the morning and afternoon loops of days two and three, when the drivers using tires from rival suppliers selected a pair of spare covers. On a number of occasions, his was the fastest Ford.
Unseasonably mild weather around the rally route turned the normally ice and snow-covered forest roads into slippery tracks coated in mud and slush, with large sections of gravel also exposed. That placed a huge onus on the grip levels of the Sottozero Ice as well as the unique stud retention system developed by Pirelli.
Each Sottozero Ice tire features 384 studs with Tungsten tips, protruding seven millimeters, which are locked into the tire to prevent stud loss in a unique vulcanization process patented by Pirelli. The tire comes in 205/65-15 size, so that it can be mounted on the same rim as used for gravel tires: a compromise between the traditional narrow shape of a snow tire and the dimensions of the gravel rim. This brings the Sottozero Ice even closer to Pirelli’s road car tires, which all benefit from the lessons learned in competition.
“I knew the Pirelli Sottozero Ice tire was good in 2010 but now it is even better,” said Norwegian Solberg, who finished seventh overall. “Winning a stage was also very good and I am very pleased. I took one spare tire in the morning and one spare tire in the afternoon, which made the car better and more fun to drive. I was the only driver who did this but it was perfect and there was no worries about the tires and the studs lasting.”
Pirelli’s senior tire engineer, Matteo Braga, said: “It was very encouraging performance and we are very pleased. Even though we have not competed in the World Rally Car class since 2010, we have not stopped working during these three years and the job we have been doing in the national championships we have contested has made a big difference. Henning was happy and confident with the tires and the balance they gave him. The stage win on day two was good, as was the second-fastest time Henning recorded on stage four. We were also very happy with the stud retention but also the quality of the studs. We experienced no problems in this respect and that was very satisfying.”
Round three of the 2014 WRC is in Mexico from March 6-9.
Bob Ulrich was named Modern Tire Dealer editor in August 2000. He joined the magazine in 1985 as assistant editor, and has been responsible for gathering statistical information for MTD's "Facts Issue" since 1993.