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Alfa Romeo U.S. Responds To Bad Giulia Quadrifoglio Dyno Results

Two days ago, we wrote about an American customer of the Alfa Romeo brand, who purchased a Giulia Quadrifoglio and started vlogging her experiences with the car.
Alfa Romeo Giulia Quadrifoglio gets tested on the dyno 1 photo
One of those experiences involved taking the vehicle to a dyno, which had the role of measuring the power and torque figures. As the uploader noted, the brand of dynamometers that was used in this test is known across the industry for its “conservative ratings,” which means that they often show less power than the vehicles they test can supply.

The phenomenon described above happens because not all dynos are built the same, which translates to some brands building “chassis dynos,” while others make “load dynos.” The former is known to offer higher figures than the previous, but this happens because the way they measure power is different.

A chassis dyno will assess power based on inertia and the spool up speed of the drums, while the load dyno places a particular charge on those drums to measure horsepower and torque. The Mustang-brand dyno that was used in the test falls into the second category.

Each type of dyno has a particular "loss," and the atmospheric conditions lead to the necessity of adjusting the results with various coefficients. Those adjustments are built-in to contemporary dynos, but the operator must carefully introduce them for optimal results. In short, dynos don’t lie, but they must get correct data every single time.

A single unintentional error in data output could lead to an erroneous value. We’re not suggesting that the specialists who tested the Giulia Quadrifoglio had made a mistake.

However, note that even the slightest change in barometric pressure, air temperature, relative humidity, air density, and even the amount of water that is supplied to the water brake can influence the results, which were already within the typical differences between a manufacturer’s figures and Mustang-brand dyno results.

The explanations provided above they come from multiple sources, and they are included in this article becasue we felt the need to explain the differences between dynos.  

Moreover, it is our obligation as journalists to provide Alfa Romeo’s response to the situation. We were contacted by the brand’s product communications representative in North America, Berj M. Alexanian, who provided us with an official statement regarding the Giulia Quadrifoglio’s horsepower and torque figures.

As Mr. Alexanian stated on behalf of the Italian brand, the 2017 Alfa Romeo Giulia Quadrifoglio’s 505 HP (or 510 PS in EMEA region) and 443 lb-ft (600 Nm) torque ratings were both verified by SAE in 2016.

The three-letter abbreviation refers to the Society of Automotive Engineers, which is responsible for numerous regulations and validations in the automotive industry.

SAE only does the validation according to the manufacturer’s figures if the measured output is within one percent of the claimed ratings in their independent dyno testing. Evidently, the Giulia Quadrifoglio passed both tests, and that led to the values mentioned above and advertised by Alfa Romeo.

The Italian brand’s representative refrained from commenting the dyno results of the customer we referred to above, and sent us the reply to clarify its stand on the matter.


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