IndyCar has announced new testing restrictions for the 2017 season, as it looks to cut costs for teams.
Four open tests will take place next year, with IndyCar teams also permitted one extra day of running between April 11 and September 17.
The window for pre-season testing begins on October 3, with each IndyCar outfit permitted three test days between then and April 6 2017.
The four open tests will take place at Phoenix from February 10-11, Barber Motorsports Park on March 21, Gateway on May 2 and at Sonoma on September 14, the same week as the 2017 finale.
Meanwhile teams can earn extra test days by running a rookie driver (up to four additional days of testing) for the season, a current Indy Lights driver (one day) or running an Indy Lights team alongside its IndyCar one (one day).
Any new teams entering the series will be allowed up to four additional days of testing, while tyre testing will take place at the request of Firestone – with any tyre tests limited to two days, with no more than two teams participating
Chevrolet and Honda engine testing is limited to two days for each manufacturer in the off-season window.
The number of tests for IndyCar teams in 2017 has come down in a bid to reduce costs, with more private test events on offer this year.
“We collaborated with all of our teams on the 2017 testing regulations with the goal of minimising the amount of in-season testing," said IndyCar president of competition and operations, Jay Frye.
“The majority of testing will take place at a series of open tests, which have been strategically routed to coincide with our race schedule.
“As we finalised our regulations, the focus was on making our test schedule more efficient and minimising the overall demands on the crews during the year.”