Studebaker Avanti engines were designated as R1 (non-supercharged) or as R2 (supercharged). These centrifugal superchargers were manufactured by Studebaker's Paxton products division. The blower provides 5 lb. of boost and is accompanied by a lower compression ratio, 9:1, and a dual breaker ignition system. In addition to the R1's and R2's, the 64 production models included 9 cars designated as R3's. The R3's were hand built racing engines. R4's were a non-supercharged version of the R3's. Approximately 140 R3/R4 engines were made. The experimental "Due Cento" with the only R5 dual supercharged engine built by Paxton reached 196.62 mph.

In piston-type internal combustion engines, an air compressor or blower is used to increase the amount of air drawn into the cylinders by the pumping action of the pistons during each intake stroke. With the additional air, more fuel is burned, and the power of the engine is thus increased. The efficiency of the charging process in an automotive engine usually rises to a peak of slightly more than 80 percent at about half the rated speed of the engine and then decreases considerably at higher speed. This change in air charge per cycle with engine speed is reflected in proportionate changes in the torque, or turning effort, applied to the crankshaft and causes the power that the engine can deliver at full throttle to reach a maximum as engine speed increases. At speeds above this peaking speed, the air charge introduced per cycle falls off so rapidly that less power is developed than at lower speeds. The inability of the engine to draw in a full charge of fresh air at high speeds limits the power output of the engine.

Supercharging overcomes this disadvantage by the use of a pump or blower to raise the pressure of the air supplied to the cylinders, increasing the weight of charge. The power loss in unsupercharged engines at high altitudes can be restored; it is possible to double the power of an engine by supercharging. Increased charge density and temperature, from supercharging, increase combustion knock or roughness in the spark-ignition engine and thus necessitates an undesirable decrease in compression ratio or the use of an antiknock fuel. The supercharging blower may be geared to the crankshaft, in which case the power consumed in driving it is added to the friction loss of the engine. A turbocharger employs a gas turbine operated by the exhaust gases to drive a centrifugal blower. The turbocharged engine gains increased power capacity and operates at improved fuel economy.