Having a luxury aimed car, your seats are softer, the ride is softer, etc etc.
Basically you don't feel the car accelerate.
I get the same in my Cressida.
I take people for a quick spin, and they don't really feel anything, then I get them to watch the speedo when I next take off and their jaws drop.
The needle climbs much much quicker than it feels like it should be.