The 2020 Alfa Romeo Giulia Quadrifoglio is a five-seat, compact luxury sport sedan packing 505 horsepower thanks to a 2.9-liter twin-turbocharged V6. My personal 2013 Dodge Challenger SRT8 392 is ... well ... not. It's a full-sized muscle coupe whose iron-block 6.4-liter V8 makes 470 hp in the very traditional way: it's freakin' huge, like everything else about the car.
On paper, these two have nothing in common beyond the fact that they were built by the same multi-national manufacturing entity.
But if paper were the be-all and end-all of automotive rankings, everybody would buy the same car. And we don't, especially as enthusiasts. Whether it's looks or tuning or vague "intangibles" or something as simple as the way a car sounds, we often put a priority on the things that trigger our emotions rather than setting out to simply buy whatever the "best" car is at that particular moment.
So, what do these two have in common? They both sound really, really good. Like looks, sounds are subjective. While a rubric most assuredly exists in the world of marketing (attraction is as much a science as any other human response), we have no way of objectively scoring the beauty of either of these cars, and the same applies to the qualities of the sound waves being emitted through their tail pipes.
But we can measure how loud they are. In fact, there's even an app for that. Dozens, as it turns out. So, I picked one at random that recorded peak loudness levels, and set off to conduct an entirely pointless and only vaguely scientific experiment with the two cars that happened to be in my garage at the same time.
For the test, I opened up a window and cracked the garage door (so as not to inflict carbon monoxide poisoning upon myself in the name of discovery), and then placed my phone on a tripod behind the center of each car's trunk lid. I fired each one up and let the app do the rest. I then placed my GoPro on top of the trunk for each test so that I could review the video afterward for any anomalies.
I started with the Challenger. The 6.4-liter Hemi under the hood of this big coupe is essentially the same lump found under the hood of quite a few Ram pickups, and it has the accessories to prove it. Its starter is loud and distinctive. Almost as loud, it turns out, as the exhaust itself. As its loud pew-pew faded behind the V8's barking cold start, we recorded a peak of 83.7 decibels. In the app's judgment, that's roughly the equivalent of a busy street. It then settled to approximately 78 decibels at high idle. The bar was set.
Up next: the Italian four-leaf clover (or four-cheese pizza, if you're as immature as the rest of us).
The Alfa is a far more delicate creation, but its door has a surprisingly solid "thunk" to it, which, as it turns out, actually spiked louder than the engine the first time I conducted the start-up test. This forced me to abandon the attempt temporarily to allow the car time to cool. This test may not have been strictly scientific, but that's no excuse to be sloppy.
Round two yielded better results. The Alfa roared to life (no squealing starter here) and immediately spiked the meter to 81.6 decibels. Once again, as loud as a busy street, but not quite as loud as the Challenger. When it comes to making noise, the colonists just do it better.
You should take these results with a grain of salt. For starters, my old Challenger has a static exhaust; the Quadrifoglio comes with a multi-mode exhaust system. In fact, it's much louder in "Race" mode, but that does us no good in a cold start situation.
Think of this more like an inexpensive dyno test result than anything precise. Ignore the numbers and focus on the gap between them. We can't say for certain that a stock 2013 Challenger's cold start measures precisely 83.7 decibels, but we can say that it's slightly louder than that of a 2020 Alfa Romeo Giulia Quadrifoglio under these specific circumstances.
At the end of the day, I got to have a little fun with a couple of cool cars on a rainy day, and you got to listen in. All in all, not a bad deal. Can you believe I get paid to do this?