rollout

Rollout or rollout allowance in North-American drag racing is the difference between actual acceleration time and measured acceleration time. For the published 0 to 60 mph acceleration time in North America, a rolling start is used, beginning 1 foot (0.3 m) after the initial standing start position. The method approximates the behaviour of dragstrip measurement equipment for 1/4 mile racing, which was historically limited to only recording after the vehicle had passed over a start line. The leads to a 0.2–0.3-second apparent difference, with larger wheel sizes giving a larger exaggeration in timing.

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