Help: Improvements
Recent entries, newest first, each compared with the racer's earlier time on the same combination; Diff is the change (negative is faster). Pacific Rift lists every repeated entry against the one before it, so a slower re-entry shows a positive Diff, and also shows the change at each split and in the number of wrecks. Apocalypse and Monument Valley list every entry and leave Diff empty when the time is the racer's first there or not faster than before.
On the Fastest board an improvement is a new best time on a track over all selected vehicles, so the vehicle can change.