What Fuel Do IndyCars Use? Shell Renewable Race Fuel (2026)

IndyCars run on Shell 100% Renewable Race Fuel, an ethanol-based fuel that is not sold at retail pumps. INDYCAR’s own car specifications list the fuel as Shell 100% renewable race fuel (ethanol), carried in an 18.5 U.S. gallon fuel cell. An updated Shell formulation with Indiana-sourced ethanol arrives for the 2027 season. This guide covers what is in the fuel, the tank size, fuel by season, how it differs from pump gas, and common myths.

What Fuel Do IndyCars Use?

The NTT INDYCAR SERIES lists Shell 100% renewable race fuel (ethanol) as the fuel for its current car, a Dallara chassis with a 2.2-liter twin-turbocharged hybrid V6 from Honda or Chevrolet. Shell is the Official Fuel of the series, and according to INDYCAR’s sustainability page the fuel arrived in 2023. Per the Aug. 21, 2026 announcement, every NTT INDYCAR SERIES race since 2023 has run on it.

The table below puts the headline facts in one place, with the source and date next to each line.

Question	What the source states	Source and date
Current fuel	Shell 100% renewable race fuel (ethanol)	INDYCAR 101 car anatomy page, 2026
Fuel supplier	Shell, Official Fuel of the NTT INDYCAR SERIES	INDYCAR Racing Toward Zero page
First used	Debuted at the open test at The Thermal Club, Feb. 2-3, 2023, for the 2023 season	INDYCAR.com, Feb. 27, 2023
Fuel cell size	Single, rupture-proof, 18.5 U.S. gallons	INDYCAR 101 car anatomy page, 2026
Next change	Updated Shell formulation for the 2027 season	INDYCAR and Shell release, Aug. 21, 2026

IndyCar Fuel Type: What Is in Shell 100% Renewable Race Fuel?

Shell and INDYCAR described the fuel in their May 27, 2022 announcement as a blend of second-generation ethanol derived from sugarcane waste and other biofuels, made so that it is 100% comprised of feedstocks classed as renewable under the applicable regulatory frameworks. The announcement credits the second-generation ethanol to Raizen, a Brazilian joint venture created in 2011 by Shell and Cosan. A Feb. 27, 2023 INDYCAR.com story adds that the fuel combines a significant mix of second-generation ethanol with another renewable component. Neither page gives a percentage split, so no ethanol-to-other ratio is quoted here.

The announcement also states that the fuel enables at least a 60% greenhouse gas emissions reduction compared with fossil-based gasoline. A footnote on the 2026 release explains the wording: the fuel is blended from components derived from biogenic wastes and byproducts that meet the renewable fuel definition in the federal Renewable Fuel Standard.

Ethanol itself is an ordinary fuel chemical. The U.S. Department of Energy ethanol basics page calls it a renewable fuel made from plant materials known as biomass, with the same chemical formula whether it comes from corn grain, sugar cane or cellulosic feedstocks. The same page says ethanol has a higher octane number than gasoline, which is why gasoline is blended with ethanol to reach the standard 87 octane, and that denatured ethanol (98% ethanol) holds about 30% less energy per gallon than gasoline.

What Changes in 2027

The Aug. 21, 2026 announcement says the updated fuel uses a significant portion of domestically sourced renewable ethanol produced from the waste stream of a grain mixture-based distilling process, and that the ethanol feedstock will be sourced from Indiana. It states a reduction of at least 70% in greenhouse gas emissions against the Renewable Fuel Standard average gasoline baseline, and that the fuel will continue to meet the performance and durability requirements of the series and its engine manufacturers.

IndyCar Fuel Capacity and How Far a Tank Goes

INDYCAR’s car specifications list the fuel cell as a single, rupture-proof cell holding 18.5 U.S. gallons. The cell is part of the carbon-fiber monocoque, and technical inspectors check the fuel cell along with chassis underwing, height, weight and width during a race weekend.

Season	Fuel cell size	Source and date
2011	22 U.S. gallons	INDYCAR.com, March 21, 2012
2012	Reduced from 19 to 18.5 U.S. gallons by a March 15 rulebook amendment, because teams could not fit 19 gallons into the cars	INDYCAR.com, March 21, 2012
2013	18.5-gallon cell; entrants chose how much E85 to start each race with	INDYCAR.com, Feb. 12, 2013
Current car	18.5 U.S. gallons	INDYCAR 101 car anatomy page, 2026

How far a tank goes depends on the track and the engine mode. The 2013 INDYCAR.com rulebook story gives a planning basis for that season: fuel allotment at the superspeedway races, which included Indianapolis, was based on 4 miles per gallon for the race distance including parade and pace laps, and the road, street and short-oval races were based on 3 miles per gallon. Simple arithmetic on those two figures puts a full 18.5-gallon cell at roughly 55 miles at 3 mpg and 74 miles at 4 mpg. Those are 2013 allotment rates for E85 cars, not a current mileage figure, so treat them as a scale and not a spec.

INDYCAR’s glossary defines the fuel window as the range of laps a car can run on a full tank, and calls it a key factor in pit strategy.

IndyCar Fuel History by Season

INDYCAR.com’s own articles give a clear trail from the early 2010s to today. The table sticks to what those pages state, with the season and source beside each row.

Season	Fuel	What the source says	Source and date
2011	100% fuel-grade ethanol	Honda 3.5-liter V8 running 100 percent fuel-grade ethanol (98 percent ethanol)	INDYCAR.com, March 21, 2012
2012	E85	85 percent ethanol and 15 percent high-octane racing gasoline; running more gasoline increases the energy content	INDYCAR.com, March 21, 2012
2013	E85	Entrants chose the amount of E85 in the 18.5-gallon cell at the start of each race	INDYCAR.com, Feb. 12, 2013
2023	Shell 100% Renewable Race Fuel	Second-generation ethanol with another renewable component; at least 60% greenhouse gas reduction versus fossil-based gasoline	INDYCAR.com, Feb. 27, 2023
2024	Same fuel, hybrid added	Hybrid power unit debuted at Mid-Ohio; Shell fuel named as an important recent innovation	INDYCAR.com, June 28, 2024
2027	Updated Shell formulation	Indiana-sourced ethanol; at least 70% reduction versus the RFS average gasoline baseline	INDYCAR and Shell release, Aug. 21, 2026

INDYCAR.com’s engine-history article also notes the sport once used pure methanol, which it describes as a key safety initiative in the 1960s Indy 500 era, before the ethanol fuels above. Methanol is no longer the series fuel. For the wider picture of car types and series, see our guide to the different types of race cars.

IndyCar Fuel vs Pump Gas

The easiest way to separate the two is where each one is sold and what the government pages say about road fuels. Race fuel is built for race engines and supplied through the series. Road cars use the fuels below.

Fuel	What the source says	Source and date
Shell race fuel for IndyCar	Not available at Shell retail stations; made for the series	INDYCAR and Shell release, Aug. 21, 2026
E10 (regular pump gas)	10% ethanol, 90% gasoline; more than 98% of U.S. gasoline contains ethanol	DOE Alternative Fuels Data Center ethanol basics
87 octane	Lower-octane gasoline is blended with 10% ethanol to reach the standard 87 octane	DOE Alternative Fuels Data Center ethanol basics
E85 (flex fuel)	Used in flexible fuel vehicles designed for any blend of gasoline and ethanol, per the page up to 83%	DOE Alternative Fuels Data Center ethanol basics
E15	Approved for model year 2001 and newer light-duty vehicles	DOE Alternative Fuels Data Center ethanol basics

So an IndyCar’s fuel is closer in spirit to E85 than to regular gasoline, but it is a purpose-built product and not simply E85 from a pump. If you drive a road car, check the owner’s manual and the fuel door label before choosing any ethanol blend. Our guides on which cars run on E85 and whether you can use E85 in a regular vehicle cover road use, and the DOE page above explains the blends.

Octane is the other common question. None of the INDYCAR or Shell pages cited here states an octane rating for the race fuel, so no number is given. If you want to understand why octane matters for knock, our explainer on the knock sensor is a good next read.

How the Hybrid Unit Fits In

INDYCAR’s technology page says the series entered a hybrid era in 2024. The system combines the 2.2-liter twin-turbocharged V6 with an energy recovery unit that captures energy during braking and redeploys it on driver demand. The hybrid unit made its race debut at Mid-Ohio and was developed jointly by Honda and Chevrolet. INDYCAR lists estimated power of 650 to 700 horsepower depending on boost pressure, plus up to 150 horsepower from the hybrid unit.

Spec	Value	Source and date
Engine	2.2-liter V6, twin-turbocharged, with hybrid technology	INDYCAR 101 car anatomy page, 2026
Maximum boost: superspeedways	1,300 mbar above atmosphere	INDYCAR 101 car anatomy page, 2026
Maximum boost: short ovals, road and street courses, Indy 500 qualifying	1,500 mbar	INDYCAR 101 car anatomy page, 2026
Maximum boost: Push-to-Pass mode	1,650 mbar	INDYCAR 101 car anatomy page, 2026

The IR-28, the new car arriving in 2028, is listed with a 2.4-liter twin-turbocharged V6 capable of up to 760 horsepower and an evolved low-voltage hybrid system that is approximately 20 pounds lighter than the current unit, per INDYCAR’s IR-28 page. That page does not state which fuel the 2028 car will use, so treat that as open. If you compare series, see IndyCar versus an F1 car and what fuel F1 cars use.

Pit Stops and the Fuel Window

INDYCAR’s glossary names two pieces of fueling hardware. The buckeye is the round external port on the side of the car where the fuel hose connects during a pit stop, and the handheld fuel probe is the device pit crews use to refuel, which locks into the buckeye for a secure, fast connection. A 2012 INDYCAR.com story explained one wrinkle: teams checked capacity one way in technical inspection and filled the car another way using the probe, and in the fast method crews could not consistently get the last two or three tenths of a gallon in.

Strategy comes from the fuel window and the tires. INDYCAR says teams plan the timing of pit stops, fuel usage and tire management, while drivers decide racing tactics, because the series has no team orders. In 2013 the rulebook let entrants pick the fuel load they started with, so a car starting deep in the field could start light and plan to fill during a yellow flag. Today the fuel cell is 18.5 gallons and the same logic of fuel window and caution timing applies. For the field size on race day, see how many cars run in the Indy 500.

Common IndyCar Fuel Myths

Myth	What the sources say
IndyCars run on regular pump gasoline	INDYCAR lists Shell 100% renewable race fuel (ethanol) for the current car, and Shell says the race fuel is not available at its retail stations
IndyCars still run on methanol	INDYCAR.com describes methanol as part of the sport’s history; the current car is listed with Shell renewable race fuel
IndyCar fuel is just E85 from the pump	E85 was the 2012 and 2013 fuel per INDYCAR.com; since 2023 the series uses a Shell-made renewable blend of second-generation ethanol and other renewable components
The fuel is sugarcane ethanol only	The 2023 fuel used second-generation sugarcane ethanol plus another renewable component; the 2027 formula is described as including ethanol from a grain mixture-based distilling process in Indiana
The hybrid means IndyCars no longer burn fuel	The hybrid unit adds stored energy to a V6 that still runs on the race fuel

What This Guide Does Not Cover

• Exact ethanol percentages and octane of the current race fuel; Shell and INDYCAR do not publish them on the pages cited here.
• Fuel rules for the 2028 IR-28 car, which INDYCAR has not stated.
• Fuel use in other racing series; see the linked F1 and race car guides for those.

Keep reading

• Best Selling 5 Is Ethanol Fuel Good for Your Car
• Fuel Types for Cars: Gasoline, Diesel, Electric & More Explained
• What Happens If I Put E85 Fuel in My Car? Damage & Fixes

Frequently Asked Questions

What type of fuel do IndyCars use?

IndyCars use Shell 100% Renewable Race Fuel, an ethanol-based fuel. INDYCAR’s car specifications list the fuel as Shell 100% renewable race fuel (ethanol), and Shell and INDYCAR describe it as a blend of second-generation ethanol and other renewable components. It has been used in every NTT INDYCAR SERIES race since 2023.

Do IndyCars use gasoline?

Not as pump gasoline. INDYCAR lists ethanol-based Shell renewable race fuel for the current car. In 2012 the series ran E85, which INDYCAR.com described as 85 percent ethanol and 15 percent high-octane racing gasoline, so some gasoline has been part of the fuel in the past.

How much fuel does an IndyCar hold?

INDYCAR lists a single, rupture-proof fuel cell holding 18.5 U.S. gallons. The cell was 22 U.S. gallons in 2011 and was set at 18.5 gallons for 2012, according to INDYCAR.com.

Can you buy IndyCar fuel at a gas station?

No. Shell states that the Renewable Race Fuel is not available at Shell retail stations. It is built for race engines, and the pump gas comparison above shows what road cars use.

Is the IndyCar fuel changing?

Yes. INDYCAR and Shell announced on Aug. 21, 2026 that an updated formulation arrives for the 2027 season, with a significant portion of ethanol sourced in Indiana and a stated greenhouse gas reduction of at least 70% against the Renewable Fuel Standard average gasoline baseline.

Do hybrid IndyCars still burn fuel?

Yes. The hybrid unit that debuted in 2024 pairs a 2.2-liter twin-turbocharged V6 with an energy recovery unit, so the engine still burns the race fuel while the hybrid stores and redeploys braking energy.

Conclusion

IndyCars run on Shell 100% Renewable Race Fuel, an ethanol-based fuel carried in an 18.5-gallon cell and not sold at retail pumps. A reformulated version with Indiana-sourced ethanol arrives for 2027. Use the season table above to see how the fuel moved from E85 to today’s blend.