Yeah, american car engineering is mind blowing. I have a 2008 Lexus IS350 - 3.5 liters V6, naturally aspirated and it produces 306 bhp. Friend has 2008 Ford Mustang - 4 liters V6, and it makes 210 bhp. What the hell.
If your friend instead had a 2011+ Mustang V6, it would have a modern(ish) engine making 305hp out of 3.7L on 87 octane, where the 2GR in the IS350 needs premium gas to make 306hp.