non-shifting design addressed this characteristic of Buick's driveline. Torque tube rear suspension was a simple design that enabled Buick to use soft coil springs while its competitors, including its corporate cousins, used harsher, firmer leaf spring, Hotchkiss drive rear suspension. Dynaflow's smooth but inefficient five element torque converter which fed power through a non-shifting direct drive (plus one manually selectable "Low gear" of 1.8:1) was the conceptual polar opposite from the Hydra-Matic used by its sister GM divisions Oldsmobile, Cadillac and then Pontiac. The contemporary Hydra-Matic, the world's first large scale successful automatic transmission, used a simple two element fluid coupling — a more efficient device than a torque converter but which provided no torque multiplication — to feed power to its fully automatic four speed planetary gearbox. Hydra-Matic's high number of gear ratios for the day compensated lack of a torque converter by including an exceptionally low first gear of 4:1. Other contemporary automatics followed the middle ground by using two or three automatic shifting gear ratios along with a relatively simple three element torque converter. Three element torque converters continue to be the norm — albeit "tighter", more efficient and less torque multiplying torque converters — even as the number of discrete gear ratios in modern 21st Century automatics continues to increase to as many as ten. The Dynaflow's gearbox section was derived from Chevrolet’s Powerglide, a two speed fully automatic planetary transmission incorporating a conventional three element torque converter. Two speed automatics with three element torque converters were common for lower priced cars of the day and in the Chrysler PowerFlite as used in the entire Chrysler Corporation lineup through 1956. Performance Dynaflow’s inefficiency earned Buick a reputation as a “gas hog” even when compared to heavy, powerful luxury cars of the 1950s and early 1960s. But at the time, gasoline was cheap and Buicks were upscale cars, so the "gas hog" reputation was not a serious sales deterrent. Manually "downshifting" from the direct drive “Drive range” to the 1.8:1 “Low range” enabled Buick's “torque monster” engines to provide very good acceleration, though frequent “downshifting” took a serious toll on transmission reliability. Arguably, a Buick “family car” wouldn't fare well during the teenage son's weekly “date night Friday” outings. Engine RPM seemed to be more a function of accelerator pedal position than of actual road speed. "Flooring" the accelerator pedal would cause the engine speed to flare