In 1961, the first-year F-85 was offered as a four-door sedan in base or Deluxe trim, or a four-door station wagon with either two or four seats, in base or Deluxe form. Initial sales were somewhat disappointing, but were soon picked up by the May introduction of a two-door sedan and the Cutlass sports coupe (a pillared two-door for 1961, which became a pillarless "hardtop" for 1962) sporting unique trim, an interior with bucket seats and optional center console, and a four-barrel version of the V8 engine, rated at 185 horsepower (138 kW). This engine was optional on other F-85s, as was a four-speed manual transmission. 80,347 F-85s were built in total. It used a full perimeter frame.
Car Life magazine tested an F-85 with the standard engine and automatic transmission, and recorded a 0-60 (0–96 km/h) time of 14.5 seconds, with a top speed just over 100 miles per hour (160 km/h). They praised its construction, but found its steering too slow and its suspension too soft for enthusiastic driving.
In 1962, the existing F-85 models returned, and a convertible was added to the line-up in September, available in both standard and Cutlass versions. The Cutlass was now a "hardtop" model, without a center post and door window frames, the previous year it had been a "coupe" with a "B" pillar and door window frames. Overall F-85 sales rose to 97,382, with the Cutlass displacing the four-door Deluxe sedan as the top-selling model.
Bigger news was the arrival of the Jetfire model, a Cutlass hardtop with a Garrett turbocharged version of the 215 V8 rated at 215 bhp (160.3 kW) and 301 lbf·ft (408 N·m), bucket seats and console, unique trim, and a vacuum gauge mounted in the console (where it was almost invisible). Although much faster than a standard F-85, the Jetfire was criticized for having the same soft suspension as its less-powerful brothers, for its lack of a tachometer and other instruments, and for the poor shift quality of both the automatic transmission and the optional four-speed. Car and Driver tested an automatic Jetfire and obtained a 0-60 time of 9.2 seconds, with a top speed of 110 mph (176 km/h). The Jetfire's high cost (nearly $300 over a standard Cutlass coupe) and reliability problems with its turbocharged engines limited sales to 3,765.
Ultimately the Jetfire engine was far ahead of its time. Instead of seeking more power by simply making a bigger engine, GM tried to perfect their novel small-block V8, which was already as such a big engine. With forced induction and an already high compression ratio the JetFire was capable of producing more torque than a conventional naturally aspirated engine that was twice its size, hence significantly improving the engines efficiency and usability in real-life driving conditions, turbo lag not being an issue at motorway speeds. But since turbo and/or supercharging the engine essentially means forcing the compression in the combustion chamber even higher, the JetFire was prone to 'spark-knock' and with out modern engine management systems the only way to mitigate this was to use a 50/50 mixture of methanol and distilled water.
Source: Wikipedia, 2012