A conventional clutch, and three- or four-speed manual transmission was installed behind the fluid coupling.
If the Fluid Drive was mated to a manual transmission, the driver still needed to use the clutch to shift between any of the gears.
Solenoids on the transmission connected to the carburetor and ignition system momentarily interrupted engine operation to allow trouble-free shifting.
The fluid drive system allowed the driver to stop at a light or in traffic and remain in gear without depressing the clutch.
For this reason, DeSotos and Dodges were favored by city cab companies from the mid Forties to early Fifties.
The semi-automatic came under a variety of names - Vacamatic, Prestomatic, Fluidmatic (Chrysler), Simplimatic, Tip-Toe Hydraulic Shift (DeSoto) and Gyromatic (Dodge).
A Fluid Drive Dodge with Gyromatic was far less expensive than a Hydramatic-equipped Pontiac, and had the effect of making city taxi-driving far easier.
In 1950, a Dodge Coronet, which had Fluid Drive standard, offered Gyromatic for $94.60 ($956.22 in 2017 dollars), while Hydramatic was a $158.50 option ($1,602.12) on Pontiacs.