Race Engineer watches how much fuel you're burning and works out again, every lap, how much you need to finish.
Most fuel calculators ask you to type in a lap time and a consumption figure once, before the race starts. Race Engineer instead reads iRacing's telemetry SDK continuously and measures your actual fuel used each completed lap, so the number adjusts itself as you save fuel, hit traffic, or the stint runs longer than planned. You never re-enter anything mid-race.
Every lap, Race Engineer recalculates fuel-to-finish from your measured burn rate: laps of fuel remaining, total fuel required to the checkered flag, whether you can finish without stopping, and (once a stop is needed) exactly how much to add. If more than one stop remains, it fills to the brim and leaves the final-stop amount for later, matching how real strategy is planned.
Race Engineer keeps several fuel-per-lap estimates at once (the whole session, the last few laps, and one that leans on your latest laps) and checks them against the car's fuel gauge. One bad reading gets caught instead of throwing off the whole strategy. Confidence shows as Low, Medium or High, depending on how many valid laps you've done.
Every prediction keeps a fuel margin above your measured need, never less than half a lap's worth, whatever else is configured. The final pit stop of the race gets extra margin on top of that: being short on an earlier stop self-corrects at the next one, but a short final stop means an unplanned emergency stop with no laps left to fix it. That distinction came from a real 2026 race where an exact-to-the-liter final stop cost five track positions.
When the numbers say you're short, Race Engineer shows exactly how much fuel-saving would close the gap, and whether that percentage is realistic, capped at a 15% ceiling.
Yes. You don't enter anything before the race. Race Engineer measures your actual fuel used lap by lap from telemetry and recalculates continuously, instead of projecting from numbers you typed in once.
It depends on how many valid laps you have done, and the app shows it as Low, Medium or High. It starts Low on the first lap and reaches High once enough clean laps are in.
A lap with a usable fuel reading. A pit lap, an invalid sensor reading, or certain off-track laps can be excluded so a single bad lap doesn't distort the average.
No. Every prediction keeps a minimum safety margin above your measured need, and the final stop of the race gets extra margin on top of that. The margin never drops to zero, regardless of settings.