Although I've had quite a few American cars..these have been mainly mid-late 70's (fuel crisis time.!) ..so most were very severely de-tuned & clogged up with emission stuff by the time I drove them.! ..most powerful is probably around the 150-160 bhp mark.! (..I have driven more powerful vehicles ... Scania Omnicity bus ..260 bhp 9-litre engine ..also Dennis Darts/pointers/tridents with engines between 175 to 330 bhp.! ..also Volvo's & leyland Olympians (all over 300bhp) ...also driven Leyland & Seddon refuse trucks in the early 80's (..unknown how powerful they were.!)
..my least powerful car ..was my Reliant Robin 850 ...40 bhp.! (..but due to it's size and light weight...it was pretty fast.!) ..my least powerful vehicle ..my first bike.. 50cc Derbi gt4v ..4.7bhp.! ..my most powerful bike .. Moto Guzzi 850 T4 with Le-Mans conversion ..(had some modifications .. somewhere around 80 bhp)