- A speed trace is the lap as one line: plateaus are straights, valleys are corners. The bottom of a valley is the corner's minimum speed; the slope into it is braking; the slope out is traction.
- Throttle and brake are the driver's feet. Where neither is pressed, the car is coasting.
- Gear steps down into a corner and up out of it; the lowest gear marks the slowest corners.
- The delta is the running gap between two laps. It climbs where one lap loses time — read its slope, not its height.
- Everything is plotted against distance, so a vertical line is one point on the track for both laps.
What telemetry is, and what the broadcast shows
A modern F1 car carries hundreds of sensors and streams their readings to the pit wall throughout a session. The teams see all of it. The broadcast shows a small, carefully chosen slice: usually speed, throttle and brake for two drivers over a lap, sometimes gear and — until 2025 — DRS, often a line showing the gap between them.
That slice is enough to understand most of what separates two laps, because lap time is made in a few places — braking zones, slow corners, the exits onto straights — and those channels describe exactly what happens there. The same channels come out of F1 25 for your own car, which is why the game is such a good place to learn to read them.
The charts on this page are two synthetic laps of a circuit the length of Monza, with five heavy braking zones: a quicker target lap in cyan and a slower lap in orange. They are the laps behind StintLab's home page, run through its analysis code — test laps rather than anyone's real lap, so everything you are told about them can be checked.
The speed trace: a whole lap in one line
Start with speed alone. Read left to right, it is the lap as the driver lived it:
- Plateaus are the straights, at the car's top speed. A higher plateau with identical pedals is the car, a tow, DRS or energy deployment — not the driver.
- Steep drops are braking zones. How far into the drop a driver waits before it starts is the braking point.
- The bottom of each valley is the corner's minimum speed — the single most telling number for a corner.
- The climb out is traction: how early and how hard the driver can use the throttle as the car straightens.
The gear trace underneath is the same story in steps: down through the gears under braking, the lowest gear at the slowest point, then up again. Count the steps and you know how slow a corner is before you read a single number.
Anatomy of a corner
Zoom into the first valley and read every channel together. This is the whole of one corner, from the end of the straight to full throttle again:
| Phase | What the traces show | What to compare between two laps |
|---|---|---|
| 1 · Braking | Throttle to zero, brake on hard, speed falling steeply, gears stepping down. Here both laps brake at 500 m and press equally hard. | Who brakes later, and how hard; how long they stay on the brake. |
| 2 · Slowest point | The bottom of the valley, usually just after the brake is released: 88 km/h in gear 2 for the target, 78 km/h for the orange lap. | Minimum speed. Ten km/h here costs time until both cars reach top speed — here, by 960 m. |
| 3 · Traction | Throttle rising as the car straightens, gears stepping up. The target reaches full throttle at 820 m. | Who picks up the throttle earlier and more firmly. |
| 4 · Exit | Full throttle again, speed climbing to the plateau. The orange lap only gets there at 960 m, and is slower at every metre in between. | Speed at the same point on the next straight — the exit speed. |
Read the delta panel last: about 0.254 s goes while braking down to the slowest point, and the other 0.367 s on the way out. Of the 0.621 s this corner costs the orange lap, more than half is lost after the braking is done — the most common lesson telemetry teaches, and the one a TV replay of the corner almost never shows.
Throttle and brake: reading the driver's feet
The pedal traces are the only channels that show the driver directly; everything else is the car's response. Four patterns are worth knowing:
- Flat out. Throttle at 100% on the straights. Long stretches of it are what a fast circuit looks like.
- Trail braking. The brake trace tapering off into the corner instead of stopping sharply before turn-in. The driver is still slowing the car while turning, to help it rotate.
- Progressive throttle. A ramp from partial to full throttle out of a slow corner. A lower, later ramp is caution — or a car that will not put the power down.
- Coasting. Neither pedal pressed. Sometimes it is deliberate — “lift and coast” to save fuel or energy, heard on team radio — and sometimes it is hesitation that costs time.
The delta: where the gap opens
Broadcast graphics often show a single number — “+0.212” — while a lap is being driven. That number is the delta: how far behind a reference lap the car is at this point. Drawn as a line over the whole lap, it becomes the most useful chart in telemetry:
The rule is simple: read the slope. Where the line climbs, time is being lost right there; where it is flat, the two laps are matching; where it falls, time is being gained. Its height at the end is the lap-time gap, but the useful information is in where it changed. Here, nearly all of the 1.317 s is made in three corners. The lap comparison guide goes deeper into reading it.
Reading a comparison like an engineer
- Find where the delta climbs. Ignore the flat stretches; the time is in the climbs.
- At each climb, compare the braking point. Later is not automatically better — check what it did to the next step.
- Compare the minimum speed. The bottom of the valley is usually where the answer is.
- Compare the throttle pick-up. Earlier and firmer usually wins the exit.
- Check the next straight. A speed difference that persists all the way down it was decided in the corner before.
- Then look for context. A difference on a straight with identical pedals is the car, a tow, DRS or energy deployment. Different fuel loads and tyres change everything a little.
What a broadcast trace leaves out
A broadcast comparison is honest but partial. It rarely shows steering, so you cannot see a driver fighting oversteer except through their throttle. It does not show tyre temperatures or fuel load, so a qualifying lap and a race lap look falsely comparable. And it seldom shows energy deployment — how the hybrid system's electrical power is used — which can change straight-line speed with no change at all in the driver's inputs. When a gap appears on a straight with identical pedals, it is one of the first suspects — alongside the exit from the corner before, and a tow.
Read your own laps the same way
F1 25 streams the same core channels for your car — speed, throttle, brake, gear, DRS — plus steering, position and your lap and sector times, as UDP telemetry you switch on in the game's settings. StintLab records every lap to your own PC on the same distance axis the charts above use, so you can overlay your best lap and your worst, or your lap and a friend's, and read them corner by corner.
The words used on this page — apex, trail braking, delta, theoretical best and the rest — are collected in the telemetry glossary.
Questions
Where can I see real F1 telemetry?
Broadcasts and F1's own channels show comparisons during sessions, and the full data stays with the teams. For recent seasons, open-source projects such as FastF1 make the public timing data and basic car channels — speed, throttle, brake, gear, DRS — available to anyone comfortable running a little Python.
What is the difference between a speed trace and a delta?
A speed trace shows how fast one car was at every point of the lap. A delta shows the running time gap between two laps: it rises wherever one lap is losing time to the other. Speed traces explain the delta; the delta tells you where to look.
Why is telemetry plotted against distance and not time?
Because two laps are only comparable at the same place on the track. Against time, the quicker car is further round the lap after the first corner and the traces drift apart; against distance, every vertical line is one point of the circuit for both drivers.
What does ‘lift and coast’ look like in telemetry?
The throttle comes off before the braking zone and the brake does not come on straight away, so for a short stretch neither pedal is pressed and the speed trace starts falling gently before the steep braking drop. Drivers do it to save fuel or energy, at a small cost in lap time.
Is F1 25 telemetry realistic?
It is the game's own physics, reported directly by the game — not a real car's sensors. The channels are the same kind the broadcast shows, and reading them works the same way, which makes the game a very good place to learn.
What do purple and green sectors mean?
Purple is the fastest time of anyone in the session for that sector; green is a driver's own best that is not the overall best; yellow is slower than the driver's own best.