Iridium spark plugs are to help drive a championship racing team as it bids to land the prestigious 2005 World Rally Championships (WRC).

Denso is supplying the iridium spark plugs, which will be used in the Subaru Impreza by the Subaru World Rally Team.

The team, which has worked with Denso since the 2004 season, is hoping the plugs will help give them the edge on their competitors.

Hiromi Tokuda, managing officer of Denso's powertrain control systems business, said that the specific structure of the tailor-made plug was key to its efficacy.

"The extremely thin iridium alloy centre electrodes ensure excellent ignition performance, leading to fewer misfires, improved acceleration and smoother driving," he explained.

"Also, by using platinum alloy on the whole ground electrode, fracture and wear are reduced even under severe racing conditions like races and rallies, and the strength and durability is increased compared to normal plugs."

Denso sells commercial variations on the spark plug as part of its Iridium Power Series in over 60 different countries.