The IZOD IndyCar Series has revealed more plans for the forthcoming 2013 season, detailing race start times and US TV coverage arrangements as well as changes to the length of four races to reduce the chance of fuel conservation strategies, and a new format for qualifying heats at Iowa.

The races which see their lengths tweaked for 2013 are the season opener in St. Petersburg, which increases by ten laps to 110 (198 miles) in total; Long Beach, which is reduced by five laps to 80 (157.4 miles); Milwaukee, which goes up by 25 laps to 250 (250 miles); and Mid-Ohio, up five laps to 90 (203 miles) in 2013.

"Changing the distances at these races will hopefully eliminate the strategy of saving fuel from the drop of the green flag," explained InyCar's race director Beaux Barfield. "That will enable our teams and drivers to race hard for the full distance and improve the event's entertainment value for the fans."

Barfield also announced a new format for qualifying heats for the Iowa Speedway race in June, building on the introduction of three heat races in 2012. Last season the drivers were placed into one of the three heats according to their combined practice times, with Race 3 alone determining the line-up of the front four rows of the grid.

This season, the three 50-lap heats will be retained but will now include transfers for the top two cars in each of Heat Race 1 and Heat Race 2 to go into a top ten pole shoot-out in Heat Race 3. The initial line-up of who lines up in which heat race will be decided by a single-car, single-lap qualification lap on the 0.875-mile, variably-banked oval.

"We wanted to change things up a little with our oval qualifying format so we introduced heat races in 2012," explained Barfield. "We did it in a way that was relatively conservative in terms of the onus that was put on teams by having to run in one heat race. Based on positive fan response and feedback, we decided to take it one step further to improve the show and put some value in it for the competitors with points."

Heat Race 1 will consist of the cars who finish the single-lap qualifying in an even position from eighth downwards; Heat Race 2 will consist of those in odd-numbered positions from seventh downwards; and Heat Race 3 will be made up of the top six from single-lap qualifying together with the top two cars transferring from the previous heats.

"Heat races at shorter tracks such as Iowa Speedway recall the heritage of oval track racing," Barfield added.

In addition to setting qualifying, the new system will also reward the top 12 on the grid with championship points with nine points going to the pole winner and then decreasing by one point until they level out at one point for the final cars in the top dozen.

Organisers hope that the ongoing changes to the qualifying system will boost attendance at Iowa Speedway over the race weekend, with Iowa Speedway CEO Doug Fritz saying that he hoped the revised format "will create some of the most exciting, edge-of-your-seat racing of the weekend."

Fritz added: "Race fans won't want to miss any of the three heat races on Saturday, since the finishing order of each one will be critical in setting the starting grid for the 'big show' on Sunday."

The tweaks to race distances and the latest changes to Iowa's qualifying together with the confirmation of race start times came on the day that the IndyCar Series announced details of its domestic TV coverage arrangements.

"The 2013 IZOD IndyCar Series television schedule was created with the goal of keeping things simple for our fans," said Robby Greene, the President and COO of IMS Productions which is the broadcast division of the IndyCar Series. "Our fans asked for more consistency and we thank our television partners and our promoters for working with us to help achieve that goal.

"The biggest point for our fans is they will be able to make IndyCar racing appointment television," added Greene. "IndyCar and our broadcast partners are offering the chance to build our audience continuity with more consistency in start times and network."

In the US, live broadcasts are shared between network broadcaster ABC and specialist cable channel NBC Sports. No details were announced of any new international broadcasting arrangements, and in particular there has been no news about broadcast rights for the UK after Sky Sports' exclusive contract to air the races expired at the end of 2012.

2013 IZOD IndyCar Series calendar

March 24, 2013 St. Petersburg Florida 110 laps, 1.8-mile street circuit - Noon (NBC Sports)

April 7, 2013 Barber Motorsports Park Birmingham, Ala. 90 laps, 2.38-mile road course - 1:30pm (NBC Sports)

April 21, 2013 Long Beach Long Beach, Calif. 80 laps, 1.96-mile street - 4pm (NBC Sports)

May 5, 2013 Sao Paulo Brazil 75 laps, 2.53-mile street circuit - 11am (NBC Sports)

May 26, 2013 Indianapolis 500 Indianapolis Motor Speedway 200 laps, 2.5-mile oval track 11am (ABC)

June 1, 2013 Belle Isle 1 Detroit, Mich. 70 laps, 2.34-mile street circuit - 3:30pm (ABC)

June 2, 2013 Belle Isle 2 Detroit, Mich. 70 laps, 2.34-mile street circuit - 3:30pm (ABC)

June 8, 2013 Texas Motor Speedway Fort Worth, Texas 228 laps, 1.5-mile oval track - 8:30pm (ABC)

June 15, 2013 Milwaukee Mile Milwaukee, Wis. 250 laps, 1-mile oval track - 4pm (NBC Sports)

June 23, 2013 Iowa Speedway Newton, Iowa 250 laps, 0.875-mile oval track - 2:30pm (ABC)

July 7, 2013 Pocono Raceway Long Pond, Pa. 160 laps, 2.5-mile oval track - Noon (ABC)

July 13, 2013 Toronto 1 Ontario, Canada 85 laps, 1.75-mile street circuit - 3pm (NBC Sports)

July 14, 2013 Toronto 2 Ontario, Canada 85 laps, 1.75-mile street circuit - 3pm (NBC Sports)

August 4, 2013 Mid-Ohio Sports Car Course Lexington, Ohio 90 laps, 2.258-mile road course - 3pm (NBC Sports)

August 25, 2013 Sonoma Sears Point, Calif. 85 laps, 2.303-mile road course - 4pm (NBC Sports)

September 1, 2013 Baltimore Baltimore, Md. 75 laps, 2.04-mile street circuit - 2pm (NBC Sports)

October 5, 2013 Reliant Park 1 Houston, Texas 90 laps, 1.7-mile street circuit - 3pm (NBC Sports)

October 6, 2013 Reliant Park 2 Houston, Texas 90 laps, 1.7-mile street circuit - 1pm (NBC Sports)

October 19, 2013 Auto Club Speedway Fontana, Calif. 250 laps, 2-mile oval - 8pm (NBC Sports)

All times are US Eastern, GMT -5