Chevrolet Vega is introduced. Body styles are notchback sedan, hatchback coupe, and kammback station wagon. The front end has single headlights, round parking lamps, egg-crate grille, and a wraparound bumper. The rear is concave with two lamps on each side. The nameplate reads "Chevrolet Vega 2300." The sedans and wagons get front manual discs. Also standard are a three-speed manual transmission with floor shifter and 6.00x13 tires. The standard engine is a 140ci (2.3l) 1bbl inline four, OHC, 3.501" x 3.625" bore and stroke, 8:1 compression ratio, producing 90hp @ 4700 RPM. An optional 2bbl carb gives the engine 110hp. Horsepower figures are pre-SAE. Options: four-speed manual transmission, automatic transmission, power steering, A/C, and Vega GT package for the coupe.
Vega's grille changed slightly. There is a new emblem on side of cowl. Tires are now A78x13. No substantial engine changes were made.
The Vega gets a new front bumper. The emblem reads "Vega by Chevrolet." A four-speed manual transmission is now standard. Under the new SAE system, the 1bbl engine is 72hp @ 4400 RPM, and the 2bbl is 85hp @ 4400 RPM. The new bumper makes the car 3" longer (173" total). New options: Estate Wagon, custom interior, and a GT package for wagon.
The Vega gets a new slanted nose with a horizontally slotted grille. The bumpers were made larger and have rubber guards, lengthing the car another 3" to 176" total. The taillamps are a single-unit style. New option: vinyl top.
Vega gets a catalytic convertor and improvements to the engine and front suspension. The 1bbl 2300 engine makes 78hp @ 4200RPM; the 2bbl makes 87 @ 4400 RPM. New options: power brakes, tilt steering, and a luggage rack. LX model gets 2bbl engine.
The Cosworth Vega is introduced. See "special or rare H-bodies."
The 7.5" rear is a new option (6.5" standard).
The 2300 engine gets new hydraulic valve lifters and other engine improvements. The Monza's torque arm rear suspension replaces the old four-link rear suspension. The Vega's grille is changed so that the parking lights are hidden behind the grille slats which run from headlight to headlight. The taillights were changed to have three sections on each side top-to-bottom. The rear drum brakes are larger (9.5" x 2").
Standard equipment: 1bbl 2300 engine (70 hp), 13x5 steel wheels with A78x13 blackwall tires, three speed manual transmission, electric fuel pump, heater/defroster, and front bucket seats.
Options: Five-speed manual transmission, automatic transmission, GT package, Freedom battery, Cabriolet appearance option.
This is the final year for the Cosworth Vega.
The four-speed manual transmission and 2bbl engine are standard with the five-speed manual or three-speed automatic optional. Slight changes are made to emissions equipment. This is the final year for the Vega.
Note: Around 4 million H-bodies were produced!
Cosworth Vega (3507 over two model years)
Some more history
The Chevrolet Vega was a subcompact car sold from 1971 through 1977. Available in coupe, hatchback and station wagon body styles (officially referred to as the Notchback, Hatchback and Kammback, respectively), it was based on the GM H platform. It was followed by the 1975 to 1980 Chevrolet Monza. The similar Pontiac Astre was available in Canada from 1973 through 1977, and in the U.S. from 1975 through 1977. The Vega was Motor Trend's Car of the Year for 1971.
The Vega was introduced as part of "Big Three" (GM, Ford, Chrysler) automakers' second foray into the subcompact car market to compete directly with the aging Volkswagen Beetle, but more importantly with Japanese imports from Toyota and Datsun that were garnering steadily increasing sales. Ford's and GM's first attempt at confronting the entry-level imports in the fall of 1960 produced the Ford Falcon and the ill-fated Chevrolet Corvair.
Most Vegas and Astres were equipped with a 2.3 L "2300" SOHC I4. The standard engine used either a single-barrel carburetor which produced about 70 hp, or a 2-barrel option which boosted output to 85 hp. These engines had cast iron heads with aluminum-silicon cylinder blocks without iron sleeves; a wear surface for the piston was created by etching the cylinder bore with an electrochemical process. Early models overheated due to poor cooling channel design. The 2300 engine typically burned oil not due to cylinder wear (which was the rumor) but instead due to poorly designed valve stem seals.
An exception was the limited-edition 1975 to 1976 Cosworth Vega, which used a fuel-injected DOHC 2.0L 16-valve version of the engine designed by Cosworth Engineering in England, and built by Chevrolet at its Tonawanda engine plant. Another exception was the 1977 model Astre, which was equipped with the 2.5 L Iron Duke engine.
The Vega was one of the first automobiles that GM produced that made extensive use of robotic welding equipment.