IndyCar tyre supplier Firestone will introduce an element of strategy to the series road and street course events by supplying an 'alternate tyre concept' at all seven such rounds in 2009.

A concept already established by sister brand in the now defunct Champ Car World Series, the option tyres - known as 'reds' due to their bright red sidewalls - are identical in body construction to the primary Firestone Firehawk slicks, but feature a softer tread compound expected to produce faster lap times, albeit at the cost of durability. Teams will thus have to balance speed against wear during both races and the three-stage Firestone Fast Six knockout-style qualifying session which features at road and street events.

"A softer tyre has more grip, but they go away quicker," Andretti Green Racing veteran Tony Kanaan confirmed, "Our races are so competitive already, this will make it even better."

Bridgestone Motorsport pioneered the 'alternate' concept in US open-wheel racing during the 2004 Toyota Grand Prix of Long Beach, and Firestone Racing executive director Al Speyer believes that this week's decision is a good one for the IRL.

"Bridgestone Americas Motorsports pioneered the alternate tyre concept and introduced it to competition, and, since that time, the idea has evolved and has been applied in other forms of motorsports," he noted, "We are further tweaking the programme for the IndyCar Series this season, and it will be entertaining to watch as it unfolds.

"It's quite a task to develop, test and approve for use a second Firestone Firehawk tyre compound for seven very different racetracks, but we believe, and many agree, that the alternate tyres will contribute another element of excitement to IndyCar Series racing."

Beginning with the 3-5 April season-opener on the streets of St Petersburg, teams will receive three sets of the alternate tyres per race weekend, with the only mandatory requirement being that one unused - or 'sticker' - set of 'reds' be used for at least two green flag laps during the race.

"I think it adds a whole different level of competition to the sport, because it's so different - a lot of times the engineering is a lot different," said Newman/Haas/Lanigan Racing's Graham Rahal, a veteran of the 'reds' from the 2007 Champ Car season.

"For instance, in Champ Car, the handling was completely different from the reds to the blacks. This is a completely different car, completely different series. It's going to be a new challenge."