The lighter wheels should have affected the outcome in a positive way.
The 2020 Ford Mustang Shelby GT500 isn't a cheap car. At $73,995 (includes destination), the ultimate Mustang is a huge leap from the 60-grand Shelby GT350R and more than twice the price of a Mustang GT without options.
But the Carbon Fiber Track Package makes the supercharged 'Stang even pricier with an additional $18,500, effectively bringing the price up near the six-digit mark. In case you aren't aware, the majority of that money for the track pack goes to the set of exposed carbon fiber wheels sourced from Carbon Revolution, an Australian company.
Gallery: 2020 Mustang Shelby GT500 Most Expensive
Just don't shatter those 17-pound carbon fiber wheels and they promise better performance at the track. At the dyno, the weight savings employed by the carbon-fiber wheels are supposed to provide lower inertia, which should increase the wheel horsepower. By how much? The video on top of this page shows a dyno run for a stock Mustang GT500 with Carbon Fiber Track Pack, which returned 677.9 horsepower (505.5 kilowatts).
Interestingly (and surprisingly), a dyno run for a Shelby GT500 without carbon-fiber wheels before returned a better output at 705 hp (526 kW) at the wheels. While we expected the lighter GT500 to have more power at the wheels, the result was opposite.
Despite the discrepancy, though, we would like to point out that this isn't an apple-to-apple comparison. There are many factors that could affect the dyno results like tire pressure, operators, and how tight the car is strapped down. In the comparison above, the machines used differ as well, which could be a huge factor for the varying results.
With that said, we should all remember that dyno results aren't biblical – unless, of course, these two cars were measured within the same facility, then the comparison would have been valid.