The Track Impulse fuel calculator is a free iRacing fuel calculator overlay. It learns your per-lap burn over 5 clean laps by default, then shows litres in tank, a pit window countdown in laps or minutes, and exactly how much to add at the next stop with your margin. No SimHub plugin, no spreadsheet, no guessing the last splash. Part of the Track Impulse overlay suite, free during beta, and it runs in nine sims.
The overlay reads fuel level straight from live telemetry, then does the arithmetic you would otherwise do on a phone between corners. It measures how much fuel each lap actually costs you, averages the clean ones, and turns that into laps left in the tank, a pit window, and a single number for the stop: how many litres to add. Nothing is typed in. Nothing is guessed.
Watch the card below run a stint. The tank drains, the bar falls with it, the pit window closes and the add-at-pit figure climbs. That is the whole loop, and it updates once a lap as each new clean lap lands.
For the first few laps the card reads LEARNING. It needs real laps of your car, your track and your driving before it will quote a burn rate. Tank level still shows from lap one.
Once enough clean laps are in, the rolling average settles and the card starts answering. Pit laps are thrown out of the average, so a fuel stop never poisons the number.
The card counts down the whole laps your tank still covers, with your safety buffer held back. In a timed race it also gives you the same window in minutes.
The green figure is the answer to the only question that matters on the approach: how many litres to put in. Deficit plus your buffer, rounded up to a whole litre.
Four numbers do all the work. Burn rate is litres per lap, averaged over your clean laps. Laps in tank is fuel divided by burn. Fuel to finish is laps left multiplied by burn. Margin is what is left over when you subtract one from the other. Every other figure on the card is derived from those.
Every time you cross the line the overlay records how much fuel that lap cost, which is simply the tank level at the start of the lap minus the tank level at the end. Those laps go into a rolling window, and the card averages them. The window is yours to set, from 3 to 10 laps, 5 by default. A short window reacts fast when you start lifting and coasting. A long window is steadier over a stint where traffic keeps changing your pace.
Not every lap counts. A lap where you pitted is discarded, because refuelling makes the lap look like it burned nothing. A lap with an implausible burn is discarded too. Until enough clean laps have landed, the card says LEARNING rather than showing a number it does not trust yet. That is deliberate: a fuel figure you cannot rely on is worse than no fuel figure.
Laps in the tank is fuel divided by burn rate. The pit window is the whole-lap version of that, with your safety buffer held back so the countdown reaching zero means you are starting to eat the buffer, not running dry. In a lap race, laps left comes straight from the sim. In a timed race there is no lap count, so the card divides the time remaining by your average lap time and rounds up, then adds a lap for the one you are on when the clock stops. That is why a timed race shows a tilde: ~36 min is an estimate built on your own pace, and it sharpens as the stint goes on.
Margin is tank minus fuel to finish. A positive margin means you can reach the flag on what you have. A negative margin, shown in red, is the deficit: that many litres short. The add-at-pit figure is that deficit plus your buffer, rounded up, because fuel rigs deal in whole litres and nobody wants to be a tenth short on the last lap. The buffer defaults to 1.0 litre and you can raise it if you run a rig where the last splash matters.
The card turns all of that into one badge so you do not have to read the numbers under pressure: SAFE, MARGINAL, SHORT, or LEARNING while it is still gathering laps.
Start lifting and coasting and your burn rate drops within a lap or two, which pushes the pit window out and shrinks the add-at-pit figure in front of you. With a short averaging window you can watch a fuel-save experiment pay off in real time instead of finding out at the stop.
One calculator, five ways to draw it. Pick the style in the overlay settings, then drag the panel wherever your eyes already go. The maths is identical in all five. What changes is how much of it is on screen at once. Every display block except tank level can be toggled off, so you can cut a style down further.
Every panel is draggable and freely resizable, and the fuel card is a natural fit along the top or bottom edge of the display where it stays out of your sightline. The overlays guide lists every setting, including the averaging window and the safety buffer.
The fuel calculator runs in nine of the ten sims Track Impulse supports. Anything that publishes a fuel level gets the full calculator. The one exception is BeamNG.drive, which does not feed it. The app detects which sim you are running and switches on its own, and outside a supported sim the overlays stay hidden.
Where a sim publishes nothing for a field, the panel reads N/A rather than inventing a number. Where an overlay cannot run in a sim at all, it says so on screen. You are never left wondering whether the gap is the sim or the app. The full per-sim support table covers every overlay in every sim.
Compared with RaceLab, iOverlay, irDashies, Edge and SimHub, Track Impulse gives you the fuel calculator free during beta, in nine sims, alongside a full overlay suite and a bass shaker engine in the same install. RaceLab puts its fuel calculator behind Pro. iOverlay, irDashies and Edge are free but iRacing only. SimHub gets there through community dashboards you assemble yourself.
Prices and features checked from each vendor's own site or repository in July 2026. Free tiers and paid plans change, so confirm at the source before you buy. Cells marked Not listed could not be confirmed from the vendor's site. irDashies and Edge are free and worth a look if all you want is an iRacing-only fuel widget. The 8ms against SimHub's 137ms is our own head-to-head measurement in iRacing on the same rig, described in the latency breakdown.
The fuel calculator is part of the Track Impulse overlay suite. There is no plugin folder, no dashboard to build and nothing to type in. From download to a working calculator is a few minutes.
Run the installer and tick the overlays component during setup. The overlays are free during beta, whether or not you use the bass shaker side of the app.
Open the fuel overlay's settings and choose your layout. Set the averaging window anywhere from 3 to 10 laps and the add-at-pit buffer in litres. The defaults, 5 laps and 1.0 litre, suit most racing.
The card reads LEARNING until it has real laps to average. Drive a handful without pitting and the burn rate, pit window and add-at-pit figure all come alive. The overlays guide covers every setting in detail.
The fuel calculator ships inside Track Impulse, next to the rest of the overlay suite and a low-latency haptic engine. That means one install gives you the fuel maths, an iRacing radar, a relative, standings and a dashboard, plus telemetry to bass shaker in as low as 2ms. Measured head to head in iRacing on the same rig, that path runs at 8ms against SimHub's 137ms.
No rival overlay app does both. RaceLab, iOverlay, irDashies and Edge draw overlays and stop there. SimHub drives bass shakers but is the 137ms side of that measurement, and its overlays are dashboards you assemble yourself. Here the same telemetry that tells you when to pit is also feeding your seat through a per-corner effect engine.
If you never plug in a bass shaker, the fuel calculator and every other overlay work exactly the same. Nothing about the overlays depends on having hardware bolted to your rig.
Updated 3 August 2026 · Written by Dennis Marinos, founder of Track Impulse
Install Track Impulse, tick the overlays during setup, and the fuel calculator is on screen for your next session. Learned burn rate, a real pit window, one number for the stop. Free during beta. No credit card.