Theoretical best lap
The lap time you already drove, just not all in one lap.
A theoretical best lap, also called an optimal lap, joins your fastest time in each zone of the circuit into one lap. Nothing is simulated and nothing is borrowed from another driver. Every piece of it is a corner you drove yourself.
The gap between it and your best actual lap is time you have already proved you can drive. Every tenth of it sits in a corner you can name.
Mobile
Web
In the product
The zone table does the assembling for you
Every lap with a column per zone, your fastest time in each one marked Best, and the theoretical best sitting above your best actual lap. The laps those zones came from stay visible, so when the theoretical best looks impossible you can see which lap owns each corner and go and check what you did there.
Where the 0.664 s sits.
The number on its own is a scoreboard. Split by zone, it becomes a plan for the next session.
Before you leave the pit lane
Three numbers that decide your next run.
Which zone holds the most time, whether it is one big loss or a dozen small ones, and which lap owns each zone's best. That is enough to choose what to work on before the next green flag.
Today this view is in the web analyzer. The same numbers come to the phone app by the end of 2026.
| Zone | Best lap | Best in session | On the table | What it usually means |
|---|---|---|---|---|
| T3 | 8.025 | 7.859 | 0.166 s | The largest single gap, and the best time here belongs to a lap from April 2023. A zone your own lap already owns is a line you know how to drive. |
| T16 | 7.916 | 7.753 | 0.163 s | The last corner before the straight, so time lost here is paid twice: once in the corner and again all the way to the line. |
| T4-T5-T6 | 12.536 | 12.403 | 0.133 s | Three corners timed as one, because they are driven on one braking. The loss can sit anywhere inside them, and the delta curve is what says where. |
A tenth and a half in one corner is a driving change. The other 0.202 s here is spread across five more zones, and that is consistency - bought with laps, not with a new braking point.
Over a day
The gap is the interesting number, not the time.
Track the difference between your best lap and your theoretical best across sessions and you are measuring consistency directly. A shrinking gap means you are stringing the lap together. A gap that stays at eight tenths while lap times drop means the car got faster and you did not.
Vetkuro keeps every session, so the comparison across three runs, or three seasons, is two clicks, not a spreadsheet built in a hotel room.
| Session | Best lap | Theoretical | Gap |
|---|---|---|---|
| Run 1 · 11 °C | 1:57.838 | 1:56.986 | 0.85 |
| Run 2 · 12 °C | 1:58.905 | 1:58.327 | 0.58 |
| Run 3 · 12 °C | 1:57.921 | 1:57.807 | 0.11 |
Autodrom Most, 9 October 2026, same car. The gap closed from 0.85 s to 0.11 s over three runs. The lap is coming together.
One session is enough to get your own number.
Record on the phone you already own. The theoretical best is there when you cross the line.
Background reading
How Vetkuro calculates it
Three steps, no model, no assumptions about the car. The numbers are from the Autodrom Most session above.
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Cut the lap into zones
One zone per corner, from the braking point or the turn-in to where the car stops accelerating and cornering. Corners taken on one braking are one zone.
- T3
- one corner
- T4-T5-T6
- one braking, one zone
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Take the fastest of each
For every zone, the quickest time from any lap you load wins, even a lap from another year. Out-laps and in-laps do not count.
- T1
- 6.944 s, lap 3
- T8
- 4.015 s, lap 2
- T3
- 7.859 s, Apr 2023
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Add them up
The sum is a lap made only of pieces you have already driven. No model, nothing simulated.
- 12 zones added up
- 1:58.241
- Best lap driven
- 1:58.905
- Within reach
- 0.664 s
Four things a theoretical best lap is not.
It is a useful number precisely because its limits are clear. Treating it as a lap time you owe yourself is how drivers end up going slower.
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Not a lap you could have driven
Your best T3 came on an early lap, your best T16 on a late one, and the car was in a different state each time. Joining twelve such zones ignores that. The gap is real, but it is not a promise.
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Not the fastest the car can go
It is bounded by what you drove that day. On a cold morning your theoretical best will be slow in absolute terms and still perfectly useful, because it measures you against yourself, in those conditions.
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Not a simulation
No model of grip, no ideal line, no assumed power curve. If a number in Vetkuro came from a model rather than from your data, it would say so. This one did not.
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Not a coaching instruction
It tells you the gap and where it sits. What to change in T5 is between you, the map, and whoever knows your car. Vetkuro does not tell you to brake later.
