Delta Time

Delta time is one of the most important tools in a race engineer's toolkit. Where a speed trace tells you how fast a car is going, the delta tells you whether that driver is winning or losing time relative to their reference. It accumulates around the lap: if a driver is 0.1s down after the first corner, 0.15s down after the second, and back to 0.1s after the third, the delta chart shows exactly where they recovered.

On the RacePace Telemetry Explorer, the delta is plotted cumulatively from the fastest reference driver. The reference driver's line is always flat at zero — every other driver's line shows how many seconds they're ahead or behind at each point on track. A rising line means losing time; a falling line means gaining.

The most revealing moments are the sudden changes. A sharp drop in the delta through a corner complex is a gain that came from a late braking point or better traction out. A long, gradual rise on a straight usually points to a top-speed deficit — either less power or more downforce. Engineers use this to identify exactly where their driver is losing tenths and to give targeted coaching during practice sessions.

Delta time is also central to race strategy. A driver's lap-to-lap delta on worn tyres versus a rival on fresh rubber tells the strategy team whether they can extend their stint further or whether they're about to be passed on track.

See the delta plot live in the Telemetry Explorer — select two or more drivers and look at the coloured delta chart below the speed trace.