The IZOD IndyCar Series is to re-introduce the 'push-to-pass' overtake assist feature, first introduced to the competition in 2009 but suspended at the start of this season while the teams got used to the new DW12 Dallara chassis and new specification turbocharged V6 2.2-litre engines from Honda, Chevrolet and Lotus introduced this year.

'Push-to-pass' adds an additional turbocharger boost from 150kPa to 160kPa and temporarily increases engine RPM in order to allow drivers to pass rivals on the track. A similar system was first used in Champ Car, and also featured in the now-defunct A1GP World Cup of Motorsport where it was called 'powerboost'.

The boost is triggered by drivers pressing a button on their steering wheel, but is only available for a pre-determined period of time depending upon the circuit and can only be used once a certain throttle position is reached. The boost ceases the minute that the driver lifts off the throttle or depresses the button a second time.

"It will be similar to what it was in the past because we know that model worked," confirmed IndyCar's vice president of technology, Will Phillips.

As well as the length of time that the boost activates for, IndyCar also sets the number of total activations and the minimum time that the system takes to 'recharge' between applications. Engine manufacturers will be allowed to tweak the settings under these limits in order to optimise 'push-to-pass' for their own units.

In essence, 'push-to-pass' is one of many solutions to the perennial problem of overtaking in open wheel competitions that rely on aerodynamic ground effects for grip; in F1, KERS and DRS are two other approaches that have been introduced for similar reasons.

Teams will be able to use the restored 'push-to-pass' feature starting with practice for July 8's Honda Indy Toronto race in Canada, and will also have the system available to them on the following the street and road courses at Edmonton, Mid-Ohio, Infineon and Baltimore in July, August and September.

However, 'push-to-pass' will not be enabled at the final race of the season at the Auto Club Speedway in Fontana, California. IndyCar organisers announced on Monday that this race will now be a 500 mile endurance race, as well as being the final race of the season now that it's confirmed there will be no replacement for the cancelled outing in China.

New penalty for Schmidt-Hamilton

In other news, IndyCar announced on Tuesday that Simon Pagenaud's #77 Schmidt-Hamilton Motorsport car had been fined $5000 for using an irregularly sized fuel cell in the Iowa Corn Indy 250 at Iowa Speedwayon June 23.

The formal announcement indicated that the fuel cell used by the team exceeded the maximum capacity of 18.5 US gallons, but that this technical breach hadn't impacted the race result in which Pagenaud finished in fifth place after starting last on the grid.