Race cars are shaped by the rules of their racing environment. An INDYCAR is about 201.7 inches long and approximately 40 inches tall, while a NASCAR Next Gen car is 193.4 inches long, 78.6 inches wide and about 3,300 pounds. Formula 1 and LMDh regulations add different constraints around mass, energy recovery, noise and aerodynamic performance. The figures below place those differences side by side using the measurement periods and rule years identified by each source.
Contents
- At a glance
- INDYCAR dimensions and running gear
- INDYCAR power, fuel and future weight
- NASCAR Next Gen specifications
- Formula 1 mass and aerodynamic changes
- Formula 1 energy and power-unit limits
- LMDh limits for endurance racing
At a glance
The following measurements use different racing categories and, in several cases, different rule years. They are not a single standardized test. The INDYCAR and NASCAR figures describe their respective car specifications, while the Formula 1 entries identify 2025 or 2026 regulations and the LMDh entries identify technical-regulation limits.
| Category | Length or minimum mass | Width or key limit | Source label |
|---|---|---|---|
| INDYCAR | 201.7 in long | 75.75–76.75 in front width | INDYCAR 101 Additional Updates |
| NASCAR Next Gen | 193.4 in long; about 3,300 lb | 78.6 in wide | NASCAR Next Gen Spec Sheet |
| F1 2026 | 768 kg minimum | 30% less downforce; 55% less drag | FIA 2026 F1 regulations release |
| LMDh | 1,030 kg minimum | 110 dB(A) maximum sound level | LMDh technical regulations |
These headline values show why “race car” is not one engineering category. A stock-car-based NASCAR design is wider and substantially heavier than the listed open-wheel INDYCAR specification. The F1 and LMDh numbers are primarily regulatory limits, including future rules and reference conditions, rather than claims about one race weekend’s setup.
INDYCAR dimensions and running gear
The INDYCAR 101 Additional Updates specification lists a race car length of about 201.7 inches. Its overall height is approximately 40 inches. The wheelbase is specified as a range from 117.5 to 121.5 inches, so the permitted span is 4.0 inches rather than one fixed value.
The standard front width is 75.75 to 76.75 inches, while the rear width is 75.66 to 76.66 inches. Oval configurations have their own width ranges: 75.91 to 76.91 inches at the front and 75.75 to 76.91 inches at the rear. These figures make the oval-specific specification slightly different from the general front and rear ranges.
The wheels are 15 inches in diameter at both axles, but their widths differ. Front wheels are 10 inches wide and rear wheels are 14 inches wide. The minimum front-wheel weight is 13.48 pounds; the minimum rear-wheel weight is 14.7 pounds. Those are wheel figures, not complete tire-and-wheel assemblies.
Tire diameter also changes by axle. At 35 psi, INDYCAR front tires measure 25 to 26 inches in diameter. Rear tires measure 26.5 to 27.5 inches at the same 35 psi reference. The rear tire range therefore begins 1.5 inches above the bottom of the front range and reaches 1.5 inches above its top.
The gearbox is an XTRAC #1011 six-speed forward unit with one reverse gear. That is a six-to-one contrast between the forward gear count and the single reverse gear, but it should not be read as a performance result; it is a specification of the transmission layout.
INDYCAR power, fuel and future weight
INDYCAR boost pressure varies by use. Superspeedway boost is listed at 1,300 mbar above atmosphere. Short ovals, road courses, street courses and Indianapolis 500 qualifying use 1,500 mbar. Push-to-pass boost reaches 1,650 mbar. The difference between the superspeedway figure and push-to-pass figure is 350 mbar above atmosphere.
The INDYCAR 101 Additional Updates estimate power output at 650 to 700 horsepower, depending on boost pressure. The hybrid system can add up to 150 horsepower. Because both values are presented as a range or maximum, they should not be combined into a single guaranteed race output. The supplied specification identifies the hybrid contribution as “up to” 150 horsepower.
Fuel is Shell 100% renewable race fuel ethanol. Fuel injection allows a maximum of two injectors per cylinder, and one direct injector operates with fuel-system pressure up to 300 bar. The two-injector allowance and one-direct-injector description are separate details of the injection system, not a statement that every operating condition uses two injectors.
The INDYCAR 2028 new car update gives a design target of reducing weight by 85 to 100 pounds versus the current chassis. This is a future target, not a measurement of the current car. The span between the lower and upper reduction target is 15 pounds, and the source does not provide a resulting final chassis weight.
NASCAR Next Gen specifications
The NASCAR Next Gen Spec Sheet lists a length of 193.4 inches, a width of 78.6 inches and a height of 50.4 inches. Its wheelbase is 110 inches and its weight is about 3,300 pounds. Compared with the INDYCAR figures above, the listed NASCAR car is 8.3 inches shorter, 2.6 inches wider than the general INDYCAR front-width maximum, and 10.4 inches taller than the approximate INDYCAR height. These are direct comparisons of supplied dimensions, not predictions about lap time.
NASCAR Next Gen wheels are 18 by 12 inches and made from forged aluminum. The front brake rotors are 15 inches, while the rear brake rotors are 14 inches. The brake-rotor diameter difference is 1 inch. The car’s engine displacement is 358 cubic inches, and the NASCAR Next Gen rules for 2022 give a baseline engine output of 670 target horsepower.
The fuel cell holds about 20 gallons and uses Sunoco Green E15. “About” applies to the capacity, while E15 identifies the fuel type in the specification. The car also uses a 4-inch rear spoiler at a majority of tracks, so that spoiler figure is tied to the stated track usage rather than every possible configuration.
The body is a composite symmetric design with OEM-specific design elements. Underneath, a full carbon undertray uses a center stepped splitter and rear diffuser. The transaxle is a five-speed manual sequential unit with a ramp-and-plate differential. Suspension uses double-wishbone billet-aluminum control arms and adjustable coil-over shock absorbers.
The braking system has six-piston monobloc front calipers and four-piston monobloc rear calipers. Together with the 15-inch front and 14-inch rear rotors, those figures describe a deliberately different front-to-rear brake specification rather than identical hardware at both axles.
Formula 1 mass and aerodynamic changes
The FIA 2026 F1 regulations release sets the minimum weight of a 2026 car at 768 kg. That minimum is 30 kg lower than the 2022 cars. The 768 kg figure includes 722 kg for the car and driver plus an estimated 46 kg of tire mass. The source describes the tire portion as estimated, so it is not a direct tire-weighing result for every event.
For context, the FIA 2024 F1 Commission statement lists the 2025 minimum car mass without fuel as 800 kg and the driver minimum weight as 82 kg. These are 2025 figures and should not be substituted for the 2026 minimum. The 2026 minimum is 32 kg below the 2025 car-mass figure without fuel, but the definitions are not identical because the 2026 description explicitly includes car, driver and estimated tire mass.
The 2026 aerodynamic changes are expressed as relative reductions: downforce is reduced by 30% and drag by 55%. These percentages describe the regulation change identified by the FIA release, not a universal measured percentage for every circuit or setup. The 2026 cars retain 18-inch wheels. Front tire width is reduced by 25 mm and rear tire width by 30 mm.
The same release lists 8.5 MJ per lap as the recoverable braking-energy total for 2026. That value is a per-lap energy limit, not horsepower and not a claim that every lap recovers exactly 8.5 MJ.
Formula 1 energy and power-unit limits
The FIA 2026 F1 power unit regulations set maximum fuel energy flow at 3,000 MJ per hour. Below 10,500 rpm, the fuel-energy-flow relationship is EF(MJ/h) = 0.27 × RPM + 165. Because this is a formula, the permitted value changes with engine speed; it should not be presented as a constant flow rate.
The 2026 MGU-K absolute electrical DC power limit is 350 kW. The total electrical DC power from the ERS-K may not exceed 350 kW as well. MGU-K energy harvested per lap may not exceed 8.5 MJ, with a possible 8 MJ exception identified in the regulations. MGU-K torque is limited to 500 Nm.
The energy store has several separate constraints. The ES state-of-charge spread may not exceed 4 MJ. The non-ERS energy-store maximum delta state of charge is also 4 MJ. Stored-energy increase in any ES may not exceed 100 kJ while the car is on track. The specified ancillary storage limit permits up to 1,000 J.
ERS-K override mode works up to 355 kph, after which power goes to zero. During a standing start, ERS-K use is limited until the car reaches 50 kph. The power-unit ancillary power limit is 350 kW.
Partial-load operation uses different fuel-energy-flow rules. Below -50 kW of engine power, the cap is 380 MJ/h. Above -50 kW, the formula is EF(MJ/h) = 9.78 × engine power(kW) + 869. These formulas and thresholds are regulatory limits for the 2026 power unit, not a promise of a particular car’s output at every point on track.
LMDh limits for endurance racing
LMDh technical regulations set a minimum car weight of 1,030 kg. Weight distribution must be homologated with a tolerance of plus or minus 0.5%. LMDh cars can accept up to 70 kg of Balance of Performance ballast above minimum car weight, so the permitted ballast amount is an added regulation allowance rather than a new minimum mass.
The ballast must withstand a minimum deceleration of 25 g in any direction. The regulations also limit maximum powertrain performance below 0.55 × Nmax to less than 246 kW. Engine speed is limited to 10,000 rpm.
LMDh reference conditions use 1,010 mbar atmospheric pressure, 12 mbar vapor pressure and a temperature of 20 C. These are test or reference conditions in the technical regulations, not a forecast of weather at every endurance race.
The on-track sound level may not exceed 110 dB(A). Supplementary panel cut-outs are limited to 15,000 mm² per side. Rear-wing vertical supports must withstand a 10 kN vertical load. These limits show how LMDh rules cover not only mass and powertrain behavior, but also noise, bodywork openings and structural loading.
The categories therefore emphasize different engineering priorities. INDYCAR specifications distinguish oval and non-oval widths and vary boost pressure by session or circuit type. NASCAR publishes a heavier, wider package with large wheels, defined brakes and a 358-cubic-inch engine. Formula 1’s 2025 and 2026 rules focus on mass, aerodynamic reduction and tightly bounded energy flows. LMDh adds homologation tolerances, ballast, reference conditions and endurance-oriented structural limits.