Fuel & Tyre Stint Calculator for Sim Racing

Whether you’re preparing for an endurance race in iRacing, calculating your stint strategy for ACC, or working out pit windows in GT7, getting your fuel calculations right is the difference between a podium finish and running out of fuel on the final lap. Our fuel stint calculator takes the guesswork out of race strategy, helping you plan your stints with confidence.

This calculator works with all major sim racing titles including iRacing, ACC (Assetto Corsa Competizione), Gran Turismo 7, F1 24, rFactor 2, Le Mans Ultimate, and Automobilista 2.

Standard Fuel Calculator

Use Laps Instead of Time

Race Length

hrs

min

Average Lap Time

min

sec

Fuel Per Lap

Results

Total Race Laps: -

Fuel Needed: -

Safe Fuel (including 2 extra laps): -

How to Use This Calculator

Getting accurate fuel calculations starts with good data. Here’s a step-by-step guide to using our calculator effectively:

Step 1: Gather Your Data

Before you can plan your race strategy, you need three key pieces of information:

Your average lap time – Not your qualifying pace, but your consistent race pace including traffic
Fuel consumption per lap – Run at least 5 laps in race conditions to get an accurate average
Race duration or total laps – Know whether you’re racing for time or laps

Pro tip: Always calculate your fuel consumption in race conditions with a full fuel load. Your car will use more fuel when heavy with fuel than when running qualifying laps.

Step 2: Choose Your Calculator Mode

Standard Calculator

Perfect for sprint races and single-stint events. This mode quickly tells you:

Total fuel needed for the race
Safe fuel amount (includes 2 extra laps as buffer)
Whether you can complete the race without stopping

Advanced Multi-Stint Calculator

Essential for endurance racing. This mode helps you plan:

Multiple stint strategies
Optimal pit stop timing
Fuel loads for each stint
Total number of stops required

Step 3: Input Your Data

For Time-Based Races:

Enter race duration in hours and minutes
Input your average lap time (be realistic!)
Add your fuel consumption per lap

For Lap-Based Races:

Toggle “Use Laps Instead of Time”
Enter the total number of race laps
Input your fuel consumption per lap

Sim-Specific Guidance

Each sim handles fuel consumption differently. Here’s what you need to know for accurate calculations:

iRacing

Units: Imperial (gallons) or Metric (litres) – check your settings
Display: Shows fuel remaining and laps remaining in real-time
Special consideration: Fuel burn varies significantly with throttle usage – coast more to save fuel
Tip: The “Fuel Required” black box shows exactly what you need to finish

ACC (Assetto Corsa Competizione)

Units: Always in litres
Tank sizes: GT3 cars typically hold 120L, GT4 cars vary (80-120L)
Special consideration: Fuel consumption changes with track temperature and engine modes
Tip: The MFD shows average consumption – wait 3-4 laps for it to stabilise

Gran Turismo 7

Units: Litres (metric only)
Display: Shows a fuel bar rather than exact numbers
Special consideration: Fuel consumption multipliers in custom races (1x to 10x)
Tip: Each segment of the fuel bar represents 10% of your tank

F1 24

Units: Kilograms (kg) – remember fuel weight affects performance
Tank size: 110kg maximum
Special consideration: Fuel mix settings dramatically affect consumption
Tip: Standard mix usually allows exactly race distance +1 lap

rFactor 2

Units: Litres or gallons depending on car
Display: Highly customisable through HUD options
Special consideration: Fuel consumption can vary between different car mods
Tip: Always verify consumption in practice – mod cars may have unrealistic values

Advanced Strategy Tips

Once you’ve mastered the basics, these advanced strategies will help you gain those crucial extra seconds:

Temperature Effects

Track and air temperature significantly impact fuel consumption:

Hot conditions: Expect 2-5% higher fuel consumption
Cold conditions: Slightly better fuel economy but watch tyre temperatures
Time of day: Evening races often see improving fuel economy as temps drop

Tyre Degradation Impact

Worn tyres affect your fuel calculations in several ways:

Lap times increase by 0.5-2 seconds per lap as tyres degrade
More wheel spin = higher fuel consumption on worn tyres
Fresh tyres after a stop can improve economy by 2-3%

Strategic Considerations

Undercut vs Overcut:

Short-filling by 5-10L can gain you 0.3-0.5s in the pit stop
But requires perfect fuel saving in the final stint
Consider track position – sometimes track position beats optimal strategy

Safety Car Windows:

Always calculate potential safety car fuel savings
Typically save 30-40% fuel per lap under safety car
Can extend stints by 3-5 laps depending on safety car duration

Common Mistakes to Avoid

Even experienced racers fall into these traps. Here’s how to avoid them:

1. Using Qualifying Pace for Calculations

Your qualifying lap might be 2 seconds faster, but your race pace is what matters. Always use realistic race lap times that account for:

Tyre degradation
Fuel load
Traffic management
Consistent pace vs pushing flat out

2. Forgetting Formation and Cool-Down Laps

These still consume fuel! Always add:

1 lap for formation/warm-up
1 lap for cool-down
0.5 laps for pit entry/exit if stopping

3. Not Accounting for Fuel Saving

You can typically save 5-10% fuel per lap through:

Lifting and coasting into heavy braking zones
Short-shifting in acceleration zones
Using lower engine modes where available

4. Ignoring Pit Stop Time Loss

Remember a pit stop costs:

GT3/GT4: 25-35 seconds (pit lane time)
Open wheel: 20-25 seconds typically
Plus: Time lost on cold tyres (1-2 seconds for 2-3 laps)

Final Thoughts

Fuel strategy can make or break your race. Whilst this calculator gives you the numbers, remember that racing is dynamic. Weather changes, safety cars, and damage can all affect your calculations. Always build in a safety margin and be prepared to adapt on the fly.

The best strategists aren’t just good at maths – they’re good at reading the race and making quick decisions. Use this calculator as your foundation, but don’t be afraid to trust your instincts when the situation changes.

Remember: It’s better to finish with 2 litres too much than to run out with 2 laps to go. The most perfectly calculated strategy means nothing if you’re watching the leaders pass by from the side of the track!