The BMW M4 has quickly become a benchmark for performance coupes, and just days after its release, enthusiasts are eager to explore its true capabilities. At keyfobx.com, we delve into the specifics of automotive performance, and we recently had the opportunity to put a brand-new Alpine White F82 BMW M4 to the test on our in-house Dynojet dyno. Following up on our previous F80 M3 dyno testing, this session aimed to uncover the real horsepower figures of the M4 and compare it to its sibling, the M3.
Dyno Performance: BMW M4 Exceeds Expectations
Similar to the Yas Marina Blue M3 we tested previously, this Alpine White M4 demonstrated that BMW’s official horsepower numbers might just be conservative. Despite the warm and humid Southern California weather, the M4 impressively registered 421whp (wheel horsepower) and 410wtq (wheel torque) using STD correction on the dyno.
These figures are noteworthy because BMW officially rates the S55 engine in the M4 at 425 horsepower at the crank. The dyno results, measuring power at the wheels, suggest that the engine is producing significantly more power than advertised. Typically, drivetrain losses can account for a reduction of around 10-15% from crank to wheel horsepower. However, the M4’s wheel horsepower is remarkably close to the claimed crank horsepower, indicating a potentially underrated factory output. This robust performance right off the showroom floor immediately positions the BMW M4 as a formidable force in its class, offering enthusiasts more power than officially stated.
Endurance Dyno Run: Heat Soak Analysis
To further assess the M4’s performance under stress, we conducted an endurance dyno test. This involved a series of five consecutive dyno runs without allowing the car to cool down between each run. The purpose of this test was to observe how the M4 responds to heatsoaking, which is a critical factor in real-world driving and especially on the track.
While the specific numbers from the endurance runs are not detailed here, this type of testing is crucial for understanding the car’s thermal management and consistent power delivery under demanding conditions. It provides valuable insights into the M4’s reliability and performance consistency when pushed hard, confirming its readiness for both street and track environments.
M3 vs M4 Weight Comparison
Alongside the dyno testing, we also took the opportunity to weigh both the F80 M3 and F82 M4 to compare their weights. It’s important to note that both vehicles were identically configured with options, except for the Mineral White M3 being equipped with optional carbon-ceramic brakes, while the Alpine White M4 had standard brakes.
The specifications and weights for each car were as follows:
2015 Mineral White BMW M3 Specs:
- 0ZDB Driver Assistance Plus
- 0ZEC Executive Package
- 0ZLP Lighting Package
- 02MK M Double-clutch Transmission (DCT)
- 02NK M Carbon Ceramic Brakes
- 02VF Adaptive M Suspension
- 02VZ 19″ Black Wheel 437 M Mix Tire
- Fuel: Empty (no driver)
- Weight: 3562lbs
2015 Alpine White BMW M4 Specs:
- 0ZDB Driver Assistance Plus
- 0ZEC Executive Package
- 0ZLP Lighting Package
- 02MK M Double-clutch Transmission (DCT)
- 02VF Adaptive M Suspension
- 02VZ 19″ Black Wheel 437 M Mix Tire
- Fuel: 1/2 Tank (no driver)
- Weight: 3579lbs
Despite the M3 having carbon-ceramic brakes, which are lighter than standard steel brakes, the M4 was only slightly heavier at 3579 lbs compared to the M3’s 3562 lbs. The M4 weighed just 17lbs more than the M3. This minimal weight difference highlights BMW’s efforts in keeping the coupe and sedan versions of the M3/M4 platform closely aligned in terms of overall weight.
Enhancing the M3: Macht Schnell Spacers and Studs Installation
Following the performance testing and weigh-in, we turned our attention to enhancing the stance and track readiness of the Mineral White M3. While the M4 remained in stock configuration for this session, we installed Macht Schnell Competition Wheel Spacers and Stud Conversion Kit on the M3.
The Macht Schnell Competition Wheel Spacer Kit included 12mm spacers for the front wheels and 15mm spacers for the rear wheels. These spacers are designed to push the wheels out, improving the vehicle’s stance and giving it a more aggressive look.
Complementing the spacers, the Macht Schnell 90mm Competition Stud Conversion Kit replaces the factory wheel bolts with studs and nuts. This conversion is particularly beneficial for track use, as it allows for faster and easier wheel changes. Studs also reduce the risk of damaging wheel threads during frequent wheel swaps.
F80 M3 Macht Schnell Spacer & Stud (New Stance)
Conclusion: BMW M4 Horsepower and Initial Impressions
Our initial dyno testing of the BMW M4 reveals that its horsepower output is likely greater than BMW’s official figures, delivering impressive wheel horsepower that nears the claimed crank horsepower. This suggests that the S55 engine is robustly engineered and potentially underrated from the factory. Combined with its lightweight construction, the M4 offers a compelling performance package right from the start. While the M4 remained stock in this test, the modifications to the M3 with Macht Schnell spacers and studs demonstrate simple yet effective enhancements to improve stance and track functionality. These initial findings confirm the BMW M4 and M3 as exciting platforms for both street and track enthusiasts, with considerable performance potential right out of the box. Special thanks to Racewerkz for providing the vehicles for this test!
