IndyCar to keep double points for Indy 500 and Sonoma finale

The series went from offering double points for its 500-mile oval events in 2014 to the Indy and Sonoma races this year, and six drivers headed to the finale in title contention.

Having led the points all season, Penske's Juan Pablo Montoya slammed the system after losing the championship on countback to Sonona victor Scott Dixon.

While Montoya did benefit from double points through his Indy 500 victory, he would have won the title had regular points been awarded all year, and IndyCar has confirmed they will stay in place in 2016.

Among a raft of rule changes announced, IndyCar is tweaking qualifying for its blue ribband event.

The first day of qualifying will determine the 33 drivers starting the 100th running of the Indianapolis 500, rather than any 'bumping' taking place on the second day.

When the field of 33 is set, times on the second day will then determine the grid, when championship points for qualifying will also be awarded.

Aerodynamic configuration for oval events have also been outlined, with rear wing angles trimmed slightly for the Iowa race, while drivers will use the 2015 Iowa package for the series' return to Phoenix.

Previously announced along with the introduction of additional tethers to keep aerodynamic parts attached, domed skid plates and rear wing beam flaps will be used at Indianapolis, Pocono and Texas, with downforce increased slightly for the latter.

The pitlane speed limit on superspeedways has been reduced to 50mph, in line with the rest of the IndyCar's venues.

A fuel additive previously allowed for Chevrolet has been scrapped, while cars with the Honda aero kit must use the chassis centre-line wicker.

IndyCar had also already announced an enhanced push-to-pass system for 2016.