The U.S. often gets downgraded versions of high-performance cars. Be it the 5-mph impact bumpers of the 1970s or down-powered engines forced to meet emissions regulations, we are sometimes left jealous of the European versions of certain cars. Today is a different day, though, because this time the U.S. gets the good one. The US-spec McLaren Senna is louder than the version sold in Europe.
Louder is better, at least when you're talking about a 789-horsepower British-born hyper exotic. The Senna's noise arrives thanks to a 4.0-liter twin-turbocharged V-8, which routes its bark through an exhaust system that exits under the rear wing. On European-spec Sennas, a trio of tailpipes is used. On the U.S.-spec car, it has a different setup comprised of just two tailpipes.
2019 McLaren Senna, Portugal Media Drive, June 2018
According to Jalopnik, the reason stems from tighter noise regulations in Europe versus the U.S. and other parts of the world. The Euro version has a third exhaust outlet, and the other two pipes have baffling that blocks them off at low speeds. The third pipe has an additional muffler, and at higher speeds the baffling opens and the exhaust flows through the upper two pipes with the lower pipe closed off.
As for the Senna sent to the U.S. and other markets, it doesn't have the third restrictive pipe and therefore the exhaust system weighs less and the car is able to sing its glorious tune even at slower speeds. This is one time when the U.S. earns a victory on the automotive spec front.
Still, the triplet of pipes on the European-spec Senna does look cooler. It's interesting because it's different and it fits the shape of the exhaust outlet space better. We assume that McLaren designed the exhaust opening to work best with the triple pipes for its home market.