It's me again, the controversial gremlin...LOL! I came across this car on the internet which is already causing some controversies. I found out it has to do with its true horsepower. Nothing new really. You see, it's well known that certain car makers, with no exception, at times either underrate or overrate the horsepower figure for one. Often on the underrate side. Anyway, having gathered this information or specs of the car to the best of my ability and information available at hand, these are the specs:

Car -> 2021 VW Golf R

Horsepower -> 315 @6,500 rpm

Torque -> 310 @310 @5,350 rpm

Weight -> 3,585 lbs including driver; 1,626 kgs

Frontal area -> 23.80 sq ft; 2.23 sq mt

Drag coefficient -> 0.275

Air density -> 1.204 kg/m^3 = 0.0000067005

Now, having achieved the following speeds which I will show on paper and in the articles showing the video also, I will use the assumed horsepower of 340 for now and see the results. Using the basic and standard drag and rolling resistance equation, I'll save you guys the trouble by having already solved these examples using different drivetrain efficiencies — 0.90, 0.85, 0.80, with the "fixed and overused" coefficient of rolling resistance of 0.015, and standard air density of 1.204 kg/m^3.

340 (345 PS) horsepower = 253,538 watts times 0.90 = 228,184 watts -> 184.87 mph -> 82.64 meters per second

340 (345 PS) horsepower = 253,538 watts times 0.85 = 215,507 watts -> 181.17 mph -> 80.99 meters per second

340 (345 PS) horsepower = 253,538 watts times 0.80 = 202,830 watts -> 177.31 mph -> 79.26 meters per second

Pn=[0.5pCdAV^2+ Cr(M+Df)g]V

where:

P = Power in watts -> 253,538

n = Drivetrain efficiency or (1 - n = power loss) -> 0.90; 0.85; 0.80

p = Rho or air density in kg/m^3 -> 1.204

Cd = Drag coefficient -> 0.275

A = Frontal area in square meters -> 2.23

V = Velocity in meters per second -> 82.64; 80.99; 79.26

Cr = Coefficient of rolling resistance -> 0.015

M = Mass of the car in kilograms -> 1,626

Df = Downforce, if any, in kilograms

g = Acceleration due to gravity -> 9.8067

According to this article, the top speed of the car, assuming the 315 hp, should only be about 167 mph. However, the video showed the speedometer reaching 289 kph, or about 179.61 mph. Now, it's not likely that 315 hp can achieve that as my calculation using different drivetrain efficiencies or power loss with a constant 0.015 coefficient of rolling resistance! These are the sites:

https://www.motor1.com/news/498540/vw-golf-r-top-speed/

https://www.motor1.com/news/495522/vw-golf-r-dyno-pull/

NOW, using my OWN method and controversial equations: According to this site, https://tirepressure.com/volkswagen-golf-r-tire-pressure#2019, I'll use both 39.0 psi and 42.5 psi which is usually the maximum tire pressure used for street rated tires. As you can see, the higher tire pressure used, the higher top speed results.

Hc = (0.00000556517pAfCdS^3+ 0.0026667CrSWt)/Pf

Pf = 5,252Hc/EpTp

Where:

Hc = Horsepower 315 (319 PS)

p = 1.204 kg/m^3

Af = 23.80 sq ft

Cd = 0.275

S = 166.94 mph @39.0 psi; 167.82 mph @42.5 psi

Wt = 3,585 lbs including driver (165)

Pf = 0.82103

Ep = 6,500 rpm

Tp = 310 lb-ft

Cr = 0.0340 @39.0 psi; 0.0320 @42.5 psi

NOW AGAIN, using this time 340 hp:

Where:

Hc = Horsepower 340 (345 PS)

p = 1.204 kg/m^3

Af = 23.80 sq ft

Cd = 0.275

S = 176.00 mph @39.0 psi; 176.87 mph @42.5 psi

Wt = 3,585 lbs including driver (165)

Pf = 0.88619

Cr = 0.0370 @39.0 psi; 0.0347 @42.5 psi

Finally, it is well established that European cars' speedometers read high due to this European Union adherence to UN ECE Regulation 39

https://www.thrillist.com/cars/your-speedometer-is-wrong-speed-calibration-inaccuracy-in-german-american-and-japanese-cars. In summary and conclusion, if the GPS-verified speed of 172 mph is to be the judge, then it is likely the car had more than 315 hp BUT less than 340 hp as suspected, the speedometer overreading as noted in the article. Thanks for the time.