Dario Franchitti and the rest of the IndyCar drivers and crews are still getting a handle on their new cars with the season opener a month away.
Franchitti says teams, drivers and engine makers "are still in that stage of not really fully understanding everything we need to." They've got a few more weeks to finetune before the first race at St. Petersburg.
The new cars have more horsepower and more grip, along with other new safety features.
Driver Scott Dixon says they are "definitely safer."
IndyCar also won't have double-file restarts on the three fast ovals at Indianapolis, Texas or Fontana in another change designed to make the sport safer. That became a huge priority after last season ended with the death of Dan Wheldon in Las Vegas.