It's 4 speeds, but starts off in second unless you really punch it, that's why it only shifts twice. If you floor it out of a light you'll feel it going from first to second - it's a more noticable shift.
Shifting points can be totally controlled by the driver. The maximum speed limit for each gear is indicated on your speedometer - one dot for first, two dots for second, and so fourth. It's on the inside of the circle under the numbers. It should be about 40Mph for first gear, and 72Mph for second.
2003 S500 Black/Charcoal
1990 560SEL 61k Arctic White/Grey
1988 420SEL Black/Palomino Sold @ 85k
1987 420SEL Midnight Blue/Grey
1986 420SEL Diamond Blue/Grey
1983 380SEL Champagne/Palomino