Is it the sticker on the air cleaner????

No bullshit, for me it’s the premium fuel requirement. You gotta put “good” gas in it, that is HP. The need for premium fuel indicates high compression or forced induction.

But just because the motor is HP, doesn’t mean the car is. Most (newer)Volvos have turbos and require premium fuel. Not what I consider a HP line of vehicles, but most of them have HP engines, which is commonplace in Luxury vehicles.