Fuel saving on an oval is not a cute side quest. It is a cold calculation about track position, pit lane time loss, and how many laps you can stretch out of a fixed tank while still keeping the car fast enough to defend.
On most ovals, the field runs close together, cautions can drop the fuel maths on its head, and passing is rarely free. That pushes teams toward a simple goal: reach the next pit cycle with less pain than the cars around you, then use clean air or a restart to cash in the track position you just bought with fuel.
Fuel saving is driven by pit lane time, not romance
Pit stops in IndyCar are quick, yet the time you lose relative to cars staying out remains huge once you include decel, pit lane speed, a stationary stop, and the accel back to race pace. That delta is why fuel saving exists. If you can remove one stop from your race, you can afford to run a slightly slower pace for long stretches and still come out ahead over a full distance.
A useful way to think about it is the “stop cost” versus “lap cost” trade. A technical example used in race engineering modelling frames it like this: a flat out pace that burns about 0.74 gallons per lap, paired with a 35 second pit loss, produces a clear fork in the road, either push and stop more times, or run a lower burn rate and aim to stop fewer times.
The reason this matters on ovals is simple: lap time spreads are tiny, the draft compresses the field, and a single extra stop can bury a car two dozen positions in traffic with no easy way back.
The hard limit: tank size and metered fuel
IndyCar does not let teams solve this by carrying a ridiculous amount of fuel. The rulebook caps the fuel cell at 18.500 US gallons. That single number defines the maximum green flag stint length, then everything else becomes engineering around that boundary.
Fuel delivery is also monitored. The same rulebook mandates a Sentronics fuel flow sensor on the car, placed as the final component before fuel enters the engine. That matters for two reasons. It standardises measurement across teams, and it gives race control a reliable reference point for fuel flow compliance.
The fuel itself is specified at series level. IndyCar’s engine regulations define the race fuel as E85, described as a nominal mix of 85 percent ethanol and 15 percent gasoline, plus an additive package set by IndyCar. Ethanol blends change the shape of the problem, with different energy content and different combustion behaviour versus pure petrol, so teams tune their approach around the fuel the series supplies, not a fantasy fuel from a lab.
What changes when a driver lifts on an oval
Fuel saving sounds like a driver simply “lifting early.” That is the visible part. The real mechanism is that throttle position changes the engine’s operating point, the aerodynamic drag the car produces, and the tyre workload over a stint.
The engine: less throttle changes burn rate fast
On an oval, a modern IndyCar spends a lot of time at high load. A small reduction in throttle, held consistently, can trim fuel burn without turning the lap into a rolling roadblock. Engineers treat this as a target burn number per lap, then work backward to find a throttle trace that hits it.
Racing engineers often model fuel saving as a controlled reduction in fuel used per segment rather than a vague instruction to “save.” One technical illustration uses a baseline fuel use of 0.301 gallons for a representative acceleration and straight segment, with a target of 0.286 gallons for a five percent saving. The key point is not the exact segment, it is the method: set a fuel target, then select engine modes and driver inputs that reach it with the least lap time damage.
This is why great fuel savers look boring on TV. They are not coasting dramatically. They are repeating an exact pattern, lap after lap, that keeps the engine in a slightly different window without tripping into poor drivability.
The aero: drag reduction is free speed if you time it
On an oval, the fastest car is often the one that spends the least time fighting aero drag. Lifting earlier reduces speed at the end of the straight, which reduces drag forces and reduces power demand. The trick is to lift at a point where you do not lose too much average speed through the corner.
The draft is the giant loophole. Following another car reduces the aero work your car must do, so you can often run the same pace with less throttle. That is why fuel saving and race craft are tangled together. The best place to save fuel is often directly behind a car you trust not to do anything stupid.
Driver techniques that add laps without bleeding lap time
Fuel saving on ovals is a driving discipline. It is repeatable, measured, and tied to the car’s balance.
Lift points and reapplication timing
A common oval pattern is lift earlier than the car ahead, then roll the centre of the corner with a stable steering trace, then reapply throttle smoothly so the rear tyres do not spike in slip. That smoothness matters. Wheelspin wastes fuel and cooks tyres, which then forces even more throttle later to recover pace.
The lift point moves with traffic. In clean air, a driver often needs a higher minimum speed to protect lap time. In a tow, the driver can lift earlier and still arrive at the corner entry at a competitive speed.
What the driver is managing, lap after lap, is a three-part constraint:
- Minimum speed through the centre of the corner
- Throttle time on the straight
- Tyre surface temperature over the stint
If any one of those goes out of range, the fuel number can look fine while the stint collapses.
Short shifting and torque control
Short shifting reduces peak torque at the tyre contact patch, which can lower wheelspin risk on restarts and in dirty air. It also changes engine load and fuel use. On ovals, short shifting is rarely about babying the gearbox. It is a way to keep the car calm while still meeting a burn target.
The useful mental model is torque management. Every time the rear tyres break traction, you spend fuel turning rubber into heat rather than speed. That is why smoothness is not just style, it is a fuel tool.
Engineering tools that make fuel saving possible
A driver cannot do this alone. The car’s calibration and the team’s live calculations shape every decision.
Fuel flow measurement and burn targets
With a mandatory fuel flow sensor in the system, teams can calculate burn rate trends and compare them to the lap target in real time. They combine that with known fuel cell capacity limits to project stint length, then decide whether a driver should hit a number aggressively or protect lap time.
IndyCar teams also work within supplied fuel constraints across an event. IndyCar has described fuel allocation approaches in the past using mpg baselines for different track types, including a four mpg basis for superspeedway distance calculations in one published explanation. The exact allocations can vary by season, yet the point for fans stays stable: teams plan fuel as a controlled resource, not as an unlimited tap.
Pit refuelling rules shape the risk
IndyCar refuelling is tightly controlled. The rulebook requires a dry break disconnect system and specifies gravity flow for refuelling. That matters for race pace and for safety, yet it also shapes how teams think about short fills, long fills, and how much time they can afford in the box.
If your fuel saving plan requires a perfect sequence of short fills under caution, you are betting the race on pit lane execution and timing. That can win, or it can ruin your day in seconds.
How cautions rewrite the maths mid-race
Ovals produce cautions. That is not a complaint, it is a property of high-speed pack racing. Cautions are also the biggest reason fuel saving matters.
Yellow laps extend the window
Under caution, the car runs slower, throttle demand drops, and fuel burn per lap drops. That stretches the effective stint length. It also creates the classic oval dilemma: pit now and restart deeper in the pack, or stay out, save fuel behind the pace car, and defend track position.
At Indianapolis, reporting and team data summaries often describe a green flag fuel window in the range of 30 to 35 laps, with caution periods stretching that number. You do not need to memorise the number. You need to understand what it does to decisions. If the window is 30 to 35 in green, then a caution at lap 28 turns a mandatory stop into an optional stop, and that changes everything.
The draft train is a fuel tool, not just a passing tool
When the field is running nose to tail, the tow lets drivers run a given lap time with less throttle. That is free fuel saving, paired with less tyre stress, paired with less engine heat load in some cases. It is also a trap, as dirty air can make the car understeer, which then forces a driver to add steering angle, scrub tyres, and lose the fuel saving they thought they were getting.
The best teams use traffic intentionally. They choose moments to tuck in and hit the number, then choose moments to run clean air and protect lap time.
The failure modes that bite teams trying to save fuel
Fuel saving is not automatically good. It carries risks that show up fast on an oval.
Overheating and drivability problems
Running a lower throttle trace changes cooling airflow and changes how long the car sits in another car’s wake. That can raise coolant and oil temperatures. It can also raise cockpit heat and make a driver’s inputs less consistent late in a stint.
Fuel-saving plans also push engines into operating points that are less forgiving. The calibration needs to keep drivability clean, or the driver will make small corrections that cost both tyres and fuel.
Tyres can punish the wrong saving pattern
If a driver lifts in a way that shifts balance mid-corner, the car can slide. Slides cost speed and spike tyre temperature. Once the tyre surface overheats, the driver needs more throttle to reach the same lap time, and the whole plan collapses into a slow car that still needs to pit.
Fuel saving works when it keeps the car stable. Any pattern that forces the driver into repeated corrections becomes expensive.
How fans can spot fuel saving without guessing
You can usually identify fuel saving from a few repeatable signs.
What it looks like onboard
You will see earlier lifts at the end of the straight and a smoother throttle reapplication. You will also see fewer aggressive steering corrections. The car looks calmer.
What it looks like in lap timing
Lap times often become slightly slower yet more consistent, with fewer spikes. The key is stint length. If the driver holds a steady pace and the stint stretches past the cars that pitted earlier, you are watching fuel saving pay off.
A team that can turn three stops into two, or can pit under a caution with the right fill, is rarely doing magic. It is doing maths, then executing it with discipline.
Resources
IndyCar Rulebook, fuel system limits and refuelling requirements.
IndyCar Engine Regulations 2024 to 2026, fuel composition E85 specification.
RACER Tech Download, IndyCar fuel saving strategies and worked numeric examples.
IndyCar Inside the Rulebook, fuel allocation approach by track type.
