According to Autosport, several configurations of the spoiler were tested, to find the perfect balance between drafting speeds, closing rates and drag levels. Also, several restrictor plates, including one-inch plus holes, have been tested, allowing some cars to reach over 210 mph in the draft.
John Darby, Sprint Cup director, declared himself happy with the results.
"We had some suck-up speeds that were a little faster than we cared for," Darby said according to the source. "In conjunction with that, we had a lot of conversations with the drivers and it became apparent the car had too much drag."
"It was good for closing up to the guy in front if you were in the middle of the pack. But if you got shuffled to the outside, the spoiler became a parachute and sucked them backwards just as fast as they were going forwards. That typically doesn't make for a good race."
The drivers on the other hand felt little difference. Apart from the fact the new version of the spoiler fixed the visibility issues in close racing of the previous version, little else was worth mentioning.
"Nothing eye-opening, it felt like it went well," Jeff Gordon said. "The cars have a little bit more turbulent air when you're behind others. It makes the car rattle and shake a little bit more, which I heard was similar to what the Nationwide cars have, so no big surprise there."