What Balance of Performance is, and how it makes rival GT3 cars lap the same time

Balance of Performance, or BoP, is the set of technical adjustments an organiser applies to cars of different design so they can lap a circuit at close to the same speed. The FIA describes it as adjustments that mainly affect weight and power, meant to balance the performance potential of cars built to different ideas, assuming each one is being driven to its limit. In GT3, SRO is blunt about the target. Its technical director Claude Surmont has said the aim is for each car to be capable of lapping within 0.3 seconds of its rivals on any sort of circuit configuration.

How the numbers are set

SRO starts with the homologation file for each car, engine dyno results and track data, then tests every GT3 model twice a year at Circuit Paul Ricard with its own drivers, on the same tyres, fuel mixture and engine settings. All of that goes into in-house simulation software that produces four separate BoP figures per car, and the type of circuit decides which one is used. The levers are power, torque, weight and aerodynamics.

Hypercar in the FIA World Endurance Championship is harder, because the class holds two different rulebooks. BoP there is built in three steps. First the FIA and ACO balance the homologation parameters, the characteristics measured when a car is inspected, scanned and run in a wind tunnel. Second comes equivalence of platforms, which compensates for the freedom an LMH design has against the common parts basis of LMDh. Third is manufacturer compensation, based on sensor data from races, which the FIA says is applied sparingly and only when the data is robust enough, and that takes several races.

The working tools are minimum weight, a power ceiling policed by torque meters on the driveshafts, maximum stint energy and average fuel load per stint. Sportscar365 reported that the FIA and ACO take the fastest car from each manufacturer, average those performances and set an undisclosed window, with ACO competition director Thierry Bouvet overseeing it. At Le Mans in 2024 a further layer arrived, power differentiation at low and high speed, modulating power above 250 kph to balance peak speeds. Le Mans also gets its own BoP, separate from the rest of the season.

What BoP is not meant to do

The FIA is clear that BoP is not designed to erase the gap between two cars built by the same manufacturer, and not designed to let an abnormally slow competitor make up the whole deficit to its rivals. It also does not replace operational performance, which means tyre management, driver ability, pit time and race craft. Sportscar365 also reported that slower cars get their adjustments later, to take away the incentive to sandbag in testing.

Why you cannot look up the numbers any more

From the 2026 season the FIA and ACO stopped publishing Hypercar BoP tables and share them only with teams. The change was set out at a media briefing at Imola before the season opener by the ACO's Bruno Famin and FIA circuit sport director Marek Nawarecki. Famin said the aim was to avoid misunderstanding, because it is difficult to explain to the public the details and differences applied to each car. His example was that telling the public one car has 20kg more or less invites wrong conclusions, since nobody outside sees the homologation data. So when a BoP figure goes around on social media now, treat it as unverified.

The Indian reason to care

BoP decides what Indian fans watch in Asian Le Mans. Arjun Maini is entered in the no64 Ford Mustang GT3 run by Haupt Racing Team in the 2026/27 season, which has a full 47 car grid split between 2 Hypercars, 16 LMP2s and 29 GT3s, from 32 teams and 16 nations. The rounds are Le Castellet on 13 to 15 November 2026, Jerez on 15 to 17 January 2027 and Portimao on 19 to 21 February 2027.

Two things follow. In a BoP grid the result mostly reflects driver pairings, pit work and traffic rather than horsepower. And since GT3 cars are racing versions of showroom machines like the 911, a GT3 win is never a clean verdict on which road car is faster.

Sources

• What is "Balance of Performance"? (24 Hours of Le Mans)
• WEC: What is Balance of Performance? (FIA)
• Blancpain GT Series Asia set for SRO's trusted Balance of Performance (GT World Challenge Asia)
• WEC Outlines Revised Hypercar BoP Process (Sportscar365)
• WEC to keep BoP data confidential for 2026 (Pit Debrief)
• Maximum 47-Car Grid for 2026/27 Asian Le Mans Series in Europe (Asian Le Mans Series)
• Le Mans Hypercar Explained (FIA WEC)