Jack Aitken’s quest to virtually wrap up the championship early is in full swing. Should the Briton leave Indianapolis with a buffer of more than 166 points over his rivals, his car would only need to cross the starting line at the Road Atlanta finale to secure the title. However, doing so will be no easy task at Indy.
While the Cadillac V-Series.R has received a relatively steady BoP for the Battle on the Bricks, several key contenders received a few breaks. Most notably, the 2026-spec factory Porsches have finally converged back toward the field, albeit while still carrying the most weight.
In a striking twist, the 2026-spec Penske Porsche even received a more favorable BoP in low-speed sections than its 2025-spec counterpart from JDC-Miller Motorsports.
Below 230 kph (143 mph)
The power-to-weight ratio for each car at Indianapolis below 230 kph is:
- Aston Martin Valkyrie - 1,962 kg/kW
- BMW M Hybrid V8 - 1,981
- Acura ARX-06 - 2,023
- Cadillac V-Series.R - 2,073
- Porsche 963 - 2,098
- Porsche 963 old - 2,116
Aston Martin remains at its 1,020-kilogram rating, a weight it has carried since Watkins Glen. The BMW M Hybrid V8 retains its Road America BoP as well, with Acura sitting third with a significant gap.
The second half of the table holds the bigger surprises: for the first time ever, the 2026-spec Porsche has received a more favorable BoP in the crucial low-speed range than the privately entered 2025-spec 963.
Furthermore, the gap between the 2026-spec Porsche and the Cadillac V-Series.R has shrunk to its lowest level since the season-opening Rolex 24 at Daytona, giving Laurin Heinrich a genuine opportunity to fight for his title hopes upon his return to the Porsche factory squad.
Looking at the changes since Road America, the 2026-spec Porsche emerges as the big winner:
- Porsche 963 -0,027 kg/kW
- Acura ARX-06 -0,007
- Aston Martin Valkyrie +-0,000
- BMW M Hybrid V8 +-0,000
- Cadillac V-Series.R +0,004
- Porsche 963 old +0,017
These changes are relatively minor, as the step between the two track profiles is less drastic than moving from Watkins Glen to Elkhart Lake. However, key differences make the power-to-weight ratio slightly less dominant here than at Road America.
The Indianapolis Motor Speedway infield features more tight S-curves and demands strong mechanical grip in low-speed turns. Compared to Road America, less time is spent at full throttle. At IMS, rolling speed through tight corner combinations and effective trail-braking are crucial.
Porsche stands out at both ends of the spectrum. For the first time since Sebring, the factory Porsche drops below 2.1 kilograms per kilowatt—underlining how difficult it was to find a suitable BoP for the updated LMDh car after its wins at both endurance classics early in the year.
Conversely, the 2025-spec 963 is only 4 kilograms lighter than its 2026 counterpart while receiving less power in low-speed sections, giving it a worse power-to-weight ratio than the newer model.
A comparison with the 2025 Battle on the Bricks shows significant gains for almost all cars, keeping in mind that all cars except the 2025 Porsche and the Aston Martin have received updates since:
- BMW M Hybrid V8 -0,125 kg/kW
- Porsche 963 -0,111
- Porsche 963 old -0,093
- Acura ARX-06 -0,084
- Cadillac V-Series.R -0,041
- Aston Martin Valkyrie -0,019
Back in 2025, the BoP baseline was largely benchmarked against the Lamborghini SC63 and Aston Martin Valkyrie, leaving all other cars with harsher ratings. That gap has since closed, with Aston Martin making the smallest gain (a 10 kg weight reduction).
The biggest jump comes from the BMW M Hybrid V8, which has enjoyed the second-best power-to-weight ratio in the class since Long Beach. After technical issues on both cars thwarted WRT’s hopes of a maiden GTP victory at Road America, BMW gets a second chance here.
Despite carrying the highest power-to-weight ratio in the field, both Porsche models still benefit from a better BoP than last year, when the 963 was restricted to 480 kW in the low-speed range. It now enjoys 30 kW more (2026 spec) and 23 kW more (2025 spec), against minor weight increases of 10 kg and 6 kg respectively.
While Acura quietly slots into the middle across all low-speed statistics, Cadillac's step is far smaller following its 1-2 finish last year—a result that kicked off Jack Aitken’s remarkable podium streak, which only came to an end at Road America after contact with Kévin Estre.
Above 240 kph (149 mph)
Due to the shorter straights, high-speed BoP is less decisive than at Elkhart Lake. However, there are two substantial straights where cars spend several seconds at full throttle above the threshold.
The power-to-weight ratios above 240 kph are:
- Aston Martin Valkyrie - 1,962 kg/kW
- Acura ARX-06 - 1,992
- BMW M Hybrid V8 - 1,997
- Cadillac V-Series.R - 2,037
- Porsche 963 old - 2,067
- Porsche 963 - 2,078
At first glance, little has changed since the last race. However, looking at the adjustments relative to Road America reveals subtle tweaks:
- Acura ARX-06 -0,017 kg/kW
- BMW M Hybrid V8 -0,014
- Aston Martin Valkyrie +-0,000
- Porsche 963 old +0,004
- Cadillac V-Series.R +0,004
- Porsche 963 +0,012
Both Acura and BMW have closed in on Aston Martin, dipping below 2.0 kg/kW. With Aston Martin, the 2025-spec Porsche, and Cadillac receiving minimal to no changes, the 2026-spec Porsche is gradually losing the power-to-weight concessions it gained prior to Watkins Glen.
Comparing high-speed power-to-weight ratios to Indianapolis 2025 highlights larger shifts, again keeping in mind the updates applied to four LMDh models:
- BMW M Hybrid V8 -0.087
- Porsche 963 old -0.032
- Porsche 963 -0.021
- Acura ARX-06 -0.019 kg/kW
- Aston Martin Valkyrie -0.019
- Cadillac V-Series.R +0.025
Once again, BMW receives the most generous break. In both speed ranges, the M Hybrid V8 boasts a better power-to-weight ratio than during its 1-2 victory back in 2024. However, direct comparisons remain complex given subsequent car updates.
With minor tweaks made to both Porsche models, Acura, and Aston Martin, the Cadillac V-Series.R stands out as the only car burdened with a worse power-to-weight ratio than last year.
Conclusion
While things look better for Porsche now, the numbers favor Acura and BMW as the top victory contenders. Both cars performed relatively well here last year, whereas Cadillac is being held back in relative terms.
Although the Acura ARX-06 only stands out once across the tables, its overall BoP position looks strong for its penultimate outing. Meanwhile, BMW fielded the fastest car at Road America but couldn't convert that pace into a result due to reliability issues. With lessons learned and a shorter race distance, expect WRT to push hard for their breakthrough IMSA GTP victory.
Porsche should be back in contention but will still have to rely on race execution, gaining positions during pit stop cycles, and extracting more performance than the raw figures suggest. Even with its most favorable BoP since the Long Beach setback, an outright victory would be a major achievement.
Cadillac faces an uphill battle, saddled with the highest power-to-weight ratio in low-speed sections while losing noticeable ground to both BMW and Acura at high speeds.
As for Aston Martin, another difficult race lies ahead due to a relative BoP disadvantage compared to last year, when its performance wasn’t too impressive. The Heart of Racing squad may have to wait for the season finale, where the Valkyrie scored its maiden podium last year.
BoP Battle on the Bricks 2026
(Differences to Road America 2026 / Indianapolis 2025 in parentheses)
Acura ARX-06
Min. Weight: 1,036 kg (-9 kg / +6 kg)
Max. Power <230 kph: 512.20 kW (-2.60 kW / +23.40 kW); 687 hp
Max. Power >240 kph: 520.00 kW (+0.00 kW / +7.80 kW); 697 hp
Max. Engine Speed: 9,512 rpm
Max. Energy per Stint: 908 MJ (-4 MJ / +11 MJ)
Fuel Replenishment: 22.700 MJ/sec (-0.100 MJ/sec / +0.275 MJ/sec)
Aston Martin Valkyrie
Min. Weight: 1,020 kg (+0 kg / -10 kg)
Max. Power <230 kph: 520.00 kW (+0.00 kW / +0.00 kW); 697 hp
Max. Power >240 kph: 520.00 kW (+0.00 kW / +0.00 kW); 697 hp
Max. Engine Speed: 8,400 rpm
Max. Energy per Stint: 908 MJ (-4 MJ / +1 MJ)
Fuel Replenishment: 22.700 MJ/sec (-0.100 MJ/sec / +0.025 MJ/sec)
BMW M Hybrid V8
Min. Weight: 1,030 kg (+0 kg / -6 kg)
Max. Power <230 kph: 520.00 kW (+7.80 kW / +28.08 kW); 697 hp
Max. Power >240 kph: 515.84 kW (-4.16 kW / +18.72 kW); 692 hp
Max. Engine Speed: 8,000 rpm
Max. Energy per Stint: 905 MJ (-1 MJ / +19 MJ)
Fuel Replenishment: 22.625 MJ/sec (-0.025 MJ/sec / +0.475 MJ/sec)
Cadillac V-Series.R
Min. Weight: 1,053 kg (+0 kg / +11 kg)
Max. Power <230 kph: 508.04 kW (-1.04 kW / +15.08 kW); 681 hp
Max. Power >240 kph: 516.88 kW (-1.04 kW / -1.04 kW); 693 hp
Max. Engine Speed: 8,800 rpm
Max. Energy per Stint: 906 MJ (-2 MJ / +5 MJ)
Fuel Replenishment: 22.650 MJ/sec (-0.050 MJ/sec / +0.125 MJ/sec)
Porsche 963 (2025 Homologation / "old")
Min. Weight: 1,066 kg (+4 kg / +6 kg)
Max. Power <230 kph: 503.88 kW (-2.08 kW / +23.92 kW); 676 hp
Max. Power >240 kph: 515.84 kW (+1.04 kW / +10.92 kW); 692 hp
Max. Engine Speed: 8,158 rpm
Max. Energy per Stint: 907 MJ (+1 MJ / +13 MJ)
Fuel Replenishment: 22.675 MJ/sec (+0.025 MJ/sec / +0.325 MJ/sec)
Porsche 963 (2026 Homologation)
Min. Weight: 1,070 kg (+4 kg / +10 kg)
Max. Power <230 kph: 510.12 kW (+8.32 kW / +30.16 kW); 684 hp
Max. Power >240 kph: 514.80 kW (-1.04 kW / +9.88 kW); 690 hp
Max. Engine Speed: 8,158 rpm
Max. Energy per Stint: 910 MJ (+3 MJ / +16 MJ)
Fuel Replenishment: 22.750 MJ/sec (+0.075 MJ/sec / +0.400 MJ/sec)
