Title contenders Scott Dixon and Helio Castroneves are among the competitors who will take a ten-place grid penalty for early engine changes ahead of Saturday night's 2013 season finale at Auto Club Speedway in Fontana, California.

With the two men the only drivers still mathematically able to win the 2013 IZOD IndyCar Series championship, the the private title battle is focus for both of them going into this week's 500-mile endurance event at the two-mile, low-banked oval superspeedway. To that end, the Ganassi and Penske teams have decided that having a fresh engine that will last the night is more important than a ten-place grid penalty that will be quickly overcome.

Other drivers who will also incur engine change penalties for the race are AJ Foyt Racing's Takuma Sato, Rahal Letterman Lanigan Racing's Graham Rahal, Sarah Fisher Hartman Racing's Josef Newgarden and Dragon Racing's Sebastian Saavedra. More teams may still opt to make changes ahead of this weekend's floodlit race.

Dixon starts with the advantage of a 25 point lead over Castroneves, who had a terrible time of it at Houston in the most recent doubleheader event at Houston. Dixon finished in third place last year at Fontana, and finished as runner-up in 2003. He also won here in 2000 when competing in Indy Lights. Castroneves was fifth at Fontana in 2012, matching his previous best performance at the venue.

Houston crash investigation still ongoing

IndyCar Series CEO Mark Miles has said that the review into the events at Houston - which began with track surface issues that disrupted the doubleheader event's schedule on Friday and Saturday, and culminated with a major accident for Dario Franchitti on the last lap of the race on Sunday - was still ongoing.

"I wouldn't even call it an investigation; it's more of a review of what happened," Miles told The Associated Press. "[We] are looking at it to look at everything that didn't go as we wanted it to go."

Franchitti suffered a concussion, bruised ribs, two broken vertebrae and a fracture to his right ankle in the accident. Now back in Indianapolis, Franchitti underwent his second round of surgery on the ankle on Monday to repair the talus bone.

"Dr Tim Weber repaired Dario's ankle and his surgery went perfectly and just as planned," reported Dr Terry Trammel, IndyCar's orthopedic consultant. "His post-operation x-rays looked great. Everything is positive at this point as Dario continues his recovery." Franchitti was reported to be "resting comfortably" after the three-hour procedure.

As well as Franchitti, a number of fans were slightly injured by debris that broke through the catchfence when the #10 Ganassi was launched into the air over the back of Takuma Sato's car.

"They're looking carefully at fencing and seat placement and all the things that came into play there," confirmed Miles. "In a way, as much as the whole weekend didn't unfold exactly the way we'd like it to have, the fence worked, the fans who sustained some injuries [which] were relatively minor. Thank God that Dario is okay in an unbelievable accident. I think we got through it and we'll learn from it."

Miles added that lessons would also be learned to ensure there is no repeat of the Friday chaos, a result of the limited time that the organisers had to set up the temporary street circuit in Reliant Park which couldn't begin until after the end of an NFL game at the venue the previous weekend.

"They had to hurry to set it up following the NFL game the weekend before, the track was inspected and approved by the FIA on Thursday night and Friday morning we figured out it's not what it needs to be," Miles admitted. "The bottom line is it wasn't what we wanted it to be. We want to make any changes necessary to avoid that sort of problem again."

The review is being undertaken by IndyCar's head of operations and competition Derrick Walker, who had not been in Houston for the build-up because of pre-existing contractual commitments to the American Le Mans Series, which will also likely see him absent from this weekends season finale at Fontana.

2014 calendar to be announced this weekend

The IndyCar Series will unveil its season schedule for 2014 this weekend, with 18 races over 14 venues expected to be confirmed by the official announcement.

Some events have already been revealed, with the series confirming on Wednesday that the series will return to the Milwaukee Mile at Wisconsin State Fair Park on August 16 and 17, with roofing wholesale distributor ABC Supply Co. Inc. serving as the title sponsor for the event and Andretti Sports Marketing once again acting as promoter.

"Racing at the Milwaukee Mile, the world's longest running race track, is always exciting," said Kevin Healy, Managing Director for Andretti Sports Marketing. "We're thrilled to announce the ABC Supply Wisconsin 250 at Milwaukee IndyFest, a new title sponsor and a new date to continue the tradition of IndyCar racing at the Mile."

"We're very excited to sponsor the race in our home state of Wisconsin at the historic Milwaukee Mile," said Diane Hendricks, founder and chairman of the board at ABC Supply. "As a sponsor of AJ Foyt Racing for almost 10 years, we're thrilled to play a small part in open-wheel racing in Wisconsin."

A new road race event at Indianapolis Motor Speedway on May 10 and a return to Pocono Raceway on July 6 have also been previously announced by the venues involved. The series is planning on completing its season by the end of August next year to avoid the current extended delay between races toward the end of the year and loss of momentum in the excitement of deciding the championship battle, and as a result the title decider - expected to stay at Fontana - will be brought forward by almost two months.

A return to Texas Motor Speedway on June 7 has also been confirmed, with next year's Firestone 600 set to be extended by 20 laps to a grand total of 248. It will take place two weeks after the Indianapolis 500, and the previous day's qualifying will be supported by a night race for the NASCAR Camping World Truck Series.

"It's always fun racing for the fans in Texas so now they'll have a little bit more to cheer about," said four-time Texas winner Helio Castroneves.

Texas Motor Speedway president Eddie Gossage also announced that the facility was investing in a new Panasonic video board display for the venue, which at 218ft by 95ft and 20,666.64 square feet of 1080 pixels-per-inch resolution will be the largest of its kind in use at a sporting facility, taking over from the current record holder at Charlotte Motor Speedway.

The races not expected to appear on the 2014 itinerary are Sao Paulo and Baltimore. The race promoter in Brazil does not have a contract with IndyCar for next season, while the organisers of the successful Baltimore event announced last month that they had been unable to find a suitable date to hold the race because of other events already taking place in the city.