The Chevrolet Monza is a subcompact, four-passenger automobile produced by the Chevrolet division of General Motors for the 1975–1980 model years. The Monza is based on the Chevrolet Vega, sharing its wheelbase, width and 140 CID (2300 cc) inline-4 engine. The 1975 Monza 2+2 was designed to accommodate the GM-Wankel rotary engine, but due to mediocre fuel economy and emissions compliance issues the engine was cancelled, and a fuel-efficient 4.3 liter V8 engine option was substituted.
The Monza 2+2 and Monza Towne Coupe competed with the Ford Mustang II and other sporty coupes. H-body variants Buick Skyhawk and Oldsmobile Starfire were produced using the Monza 2+2 body with grill and trim variations and Buick's 3.8 liter V6 engine. The Pontiac Sunbird variant was introduced the following model year, eventually offered in both Monza body styles. The Monza nameplate originated in mid-1960 for the sporty version of the Chevrolet Corvair.
The Monza 2+2, Chevy's sporty successor to the Vega debuted as the single-model 2+2 hatchback. The Monza is 4 inches (100 mm) longer and weighs 180 pounds more than the Vega from which it is derived. John DeLorean nicknamed it the Italian Vega citing styling with a strong resemblance to the Ferrari 365 GTC/4.
The 1975 Monza was initially slated to introduce the GM Wankel rotary engine which is licensed from NSU. Notable rotary issues included mediocre fuel economy compounded at a time of comparatively high fuel prices following the Arab oil boycotts of 1973 and 1974, and GM canceled the engine. Thus the 1975 Chevrolet Monza was launched carrying conventional piston engines instead.
The 1975 Monza 2+2 wore its newly approved rectangular headlights and a slot-style grille in a slanted nose made of resilient urethane. The side window louvers are functional, part of the flow-through ventilation system. The Monza 2+2's two-door hatchback body style was shared with the Oldsmobile Starfire and Buick Skyhawk. The standard Monza engine was the Vega aluminum-block 140 CID (2.3 liter) inline-4 engine with a single barrel carburetor generating 78 horsepower (58 kW) at 4200 rpm. Optional was the 2-barrel carburetor version that generates 87 horsepower (65 kW) at 4400 rpm. Chevrolet's new 4.3 liter (262 cid) V-8 engine was optional. The smallest V8 ever offered by Chevrolet, it features a Rochester 2-barrel carburetor and generates 110 horsepower (82 kW) at 3600 rpm. For 1975 only, Monzas sold in California and high altitude areas met the stricter emissions requirnment by substituting a version of the 5.7 liter (350 cid) V8 engine with a 2-barrel carburetor tuned to just 125 hp (93 kW). The Monza 2+2 and its Buick and Oldsmobile variants feature GM's first use of a torque arm rear suspension, also adopted for the 1975 Cosworth Vega introduced mid-1975, and later, all 1976-77 Vegas and Pontiac Astres. The basic design was also incorporated into GM's third and fourth generation F-bodies, Chevrolet Camaro and Pontiac Firebird.
In April 1975, the Monza Towne Coupe was introduced - a notchback body-style with a conventional trunk featuring different sheetmetal than the 2+2 hatchback, although sharing its windshield, front fenders, and doors. It features single round headlamps, instead of the dual rectangular headlamps on the 2+2. The Towne Coupe was offered in response to the sales success of the Ford Mustang II notchback coupe and its luxury version, the Mustang II Ghia. The Towne Coupe is 1.5 inches (38 mm) shorter and 135 pounds (61 kg) lighter than the 2+2 and has slightly more rear head room. A lower priced "S" version of the 2+2 Hatchback was introduced mid-year. It featured as standard the Vega 1-barrel engine with a 3-speed manual transmission. The sport suspension, full console, sport steering wheel, day/night and wheel opening moldings were deleted on the "S". The Chevrolet Monza 2+2 won Motor Trend magazine's "Car of the Year" award for 1975.
Model year changes
The 1976 140-cubic inch four-cylinder engine, as used in the Vega got some refinements. Named "Dura-built 140", it features quieter hydraulic lifters eliminating valve adjustments. The basic four developed 70 horsepower, but two-barrel carburetion upped the rating to 84. 1976 saw the introduction of Chevrolet's new 5.0 liter (305 cid) V-8 engine with a 2-barrel carburetor generating 140 horsepower (100 kW) at 3800 rpm, but only for California and high-altitude Monza customers, and replaced the 350 CID (5.7 liter) V-8. The 262 V8 was again, the optional engine in the 49 states. A mid-year option for the 1976 model year was a sport front end available for the Towne Coupe, which features the 2+2's urethane front end and quad headlamps. The Monza Spyder option package was first introduced in 1976. It features a 2-barrel carburetor version of the 4-cylinder engine as standard, a floor console, F41 suspension with larger front and rear stabilizer bars, and special shock absorbers. This equipment had been standard on the original 1975 2+2 (excluding the mid-year 'S' model).
The 1977 Monza was highlighted by the addition of a two new Spyder option packages, a $274 performance package, the other a $199 appearance add-on package that was available only on hatchbacks. An 84-horsepower four-cylinder engine was standard, but Monzas could be ordered with a 145-horsepower 305-cubic-inch V-8 instead. The Monza dashboard contained round gauges in a brushed-aluminum instrument panel. The Towne Coupe Cabriolet was deleted, but a half-vinyl roof and opera windows could still be ordered. The Monza Mirage was produced by Michigan Auto Techniques, an aftermarket company contracted by GM. The Mirage is painted white, with red and blue racing stripes along the length of the car. It also features flared body panels, and a special airdam & spoiler. The vehicles were built in GM's St. Therese plant, and sent to MAT for modification, after which they would ship completed cars to the dealer. There were approx 4,097 1977 Mirages made from MAT, but there were also Mirages created by Chevrolet dealerships, as the body add-ons and stripes were available ordered through dealer parts. The 5.0 liter (305 cid) engine was the only V8 option for the 1977 model year. The standard Vega 2.3 aluminum-block engine was discontinued at the end of the model year, replaced with the Pontiac 2.5 "Iron Duke."
The 1978 Monza line expanded to include rebadged holdovers from the Vega line, which ended production after the 1977 model year. Chevy grafted a new Monza front end onto the previous Vega hatchback and wagon body-styles. The Monza 'S', marketed as the Monza price leader, used the Vega hatchback body. With production of only 2,000 units, it was speculated that this was simply an effort to use up a stock of leftover 1977 Vega bodies. The Monza wagon was also offered in an Estate wood-trimmed version, used the Vega wagon body. The 1978 Monza line gained a new base coupe and 2+2 hatchback with round headlights in an upright front end with a crossbar grille. The Sport 2+2 hatchback and Sport notchback used a modified version of the previous quad rectangular headlamps, now above a full-width open-slot grill. The 151 CID (2.5 liter) inline-4 'Iron Duke' was standard for 1978, replacing the Vega inline-4 engine. Engine options were a Chevrolet-designed 3.2 liter (196 cid) V-6 engine with a 2-barrel carburetor that produced 90 horsepower (67 kW) at 3600 rpm. Replacing the 3.2 liter V-6 in California and high-altitude areas was Buick's 3.8 liter (231 cid) 105-hp V-6 engine. Four-cylinder engines and the 3.2 liter V-6 were not available in high-altitude areas. The 145-horsepower 305-cubic-inch V-8 remained optional in all but the "S" hatchback and wagon models. Discontinued at the end of the 1978 model year were the 'S' hatchback, Towne Coupe Sport option and the Estate version of the wagon.
The 1979 Chevrolet Monza linup was trimmed to four models. Added standard equipment for 1979 included an AM radio, tinted glass, bodyside moldings, and sport steering wheel. Only one Monza model kept the sloped Euro-look front end, the 2+2 Sport hatchback. Others had a freshened grille. A more-potent standard 151-cubic-inch (2.5-liter) four-cylinder with a redesigned cross-flow cylinder head and two-barrel carburetor developed 90-horsepower - five more than in 1978. Three optional engines were available: the 105-horsepower 196-cubic-inch V-6, 115-horsepower 231 V-6, or 130-horsepower 305 V-8. The Spyder performance package cost $164, the Spyder appearance package added $231. All Monzas had a color-keyed instrument panel, and all except the base coupe had a center console, and corrosion protection was improved. Discontinued at the end of the 1979 model year were the Monza wagon, the 196 CID (3.2 liter) V6 and the 305 CID (5.0 liter) V8.
The 1980 model year lineup consisted of a base 2+2 hatchback and notchback and 2+2 Sport hatchback; the 151-cubic-inch (2.5-liter) four-cylinder engine remained standard; the only engine option was the 3.8 liter (231 cid) Buick V6. Chevrolet decided to shelve the antiquated design and let base models of the Chevrolet Camaro and the new Chevrolet Citation X-11 hold the division's place sporty-coupe market.
The Spyder nameplate was originally used to designate the 1962-1964 Corvair turbocharged model. The 'Spyder' name was introduced for the Chevrolet Monza in 1976. This package included performance equipment and some small appearance items. The Monza Spyder Equipment package was available on all 2+2 Hatchbacks and Monza Towne Coupes (with 'Sport Equipment' package) with 5-speed manual and Turbo Hydra-matic automatic transmissions. The Spyder Equipment package included 2-barrel, Dura-Built 2.3 litre engine, floor console unit, large front/rear stabilizer bars, special shock absorbers, steel-belted radial ply blackwall tires, wheel opening mouldings (chrome), Day-Night inside mirror, Sport Steering Wheel (2-spoke wheel), Special instrumentation and 'stitched' instrument panel pad with added wood-grain vinyl accents (standard on 2+2), Distinctive "Spyder" identification (script fender emblems, steering wheel horn button insert and Spyder front facia and rear-lock cover)
Chevrolet made extensive changes to the Spyder package including separate Equipment and Appearance packages with separate RPO codes found on the build sheet. The Spyder Equipment Package was regular production option (RPO) Z01, while the Spyder Appearance Package was RPO Z02. The Spyder packages were available on Monza 2+2 Sport Hatchback. Spyder decal colors were determined by the body color of the Monza ordered. There were 4 color combinations for 1977. For 79, there were 6 combos, which included a green and a blue color scheme.
Z01 - Spyder Equipment
-- BR70-13C Steel-belted radial ply blackwall tires, Sport suspension, Sport Steering Wheel (2-spoke wheel), Center Console, Inside day/night rearview mirror, Spyder identification, Wheel opening moldings (available if the Z02 - Spyder Appearance Package was not ordered), Dual tailpipe system and white lettered tires were available in 1979.
Z02 - Spyder Appearance -- Black highlights on front, side and rear of body headlight openings, parking light openings, windshield, rear window and side window moldings, body sill, door and center pillar louvers, rear end panel - (bright window moldings with black exterior), Black or gold rear accents (taillight blackouts and rear end panel decals), Body color front air dam and rear spoiler, Spyder emblems (front facia, rear lock cover and sport steering wheel horn button insert), Body side stripes with Spyder lettering in red, white or gold depending on body color, Black painted styled-steel wheels with trim rings and center caps, Black sport mirrors, Special hood decal and rear spoiler decal.
For the 1980 model year, Chevrolet combined the Spyder Equipment and Appearance packages into one Spyder Equipment package with an RPO code of Z29 and included newly re-designed bold Spyder side decals and a new front air dam that blends into the front fender wheel openings. Spyder decal color choices (five) were based primarily upon the interior color specified rather than the body color as in previous years.
Z29 - Spyder Equipment Package -- BR70-13C steel-belted radial ply blackwall tires (with option for raised white lettering), Sport suspension, Black front and rear bumper rub strips, Black headlights frames, Black windshield, belt, side and rear window moldings (not available with black exterior), Black painted body sill (also not available with black exterior), Black door and center pillar louvers, Black painted taillight frames, Body color front air dam and rear spoiler, Spyder emblems on front facia, rear lock cover and sport steering wheel (horn button insert), Black sport mirrors (LH remote, RH manual), Rear Spoiler and body stripes with Spyder lettering outlined in accent body colour, Spyder hood decal, Black painted Rally II wheels with bright trim rings and center caps.
Stillborn Wankel engine
In November 1970, GM paid $50 million for initial licenses to produce the Wankel rotary engine, and GM President Ed Cole projected its release in three years. The GM Wankel was initially targeted for an October 1973 introduction as a 1974 Vega option. The General Motors Rotary Combustion Engine (GMRCE) had two rotors displacing 206 cu in (3.38 l), twin distributors and coils, and aluminum housing.
Unwilling to face gas mileage criticism that Mazda withstood, GM felt it could meet 1975 emissions standards with the engine tuned to provide better mileage. Other refinements improved mileage to a remarkable 20 mpg, but with the fuel breakthrough came related side-effect problems — apex seal failures, as well as a rotor tip-seal problem. By December 1973, it was clear the Wankel, now planned for the Monza 2+2, would not be ready for either production or emissions certification in time for the start of the 1975 model year and after paying another $10 million against its rotary licence fees, the company announced the first postponement. Motor Trend in April 1974 predicted the final outcome — On September 24, 1974, Ed Cole postponed the Wankel engine ostensibly due to emissions difficulties. He retired the same month. GM admitted fuel economy for the rotary was sub-standard and postponed production in favor of further development. Pete Estes succeeded Ed Cole as GM President and never showed any special interest in the Wankel or in the perpetuation of Cole's ideas.
End of the H-body
A total 731,504 Monzas were produced in six model years. The rear-wheel drive (RWD) H-body Monza, Sunbird, Skyhawk, and Starfire were replaced in the spring of 1981 with a new front-wheel drive (FWD) line-up, the J-car models: Chevrolet Cavalier, Oldsmobile Firenza, Buick Skyhawk, and the Pontiac J2000 introduced as 1982 models. Because the forthcoming J-body cars were to be sold as 1982 models, there was a long production run of 1980 H-body models in order to provide sufficient inventory to carry dealers until the spring of 1981.
Chevrolet Monzas participated in the IMSA GT Series powered by Chevrolet Corvette engines. Chevrolet Monzas were the challengers in the new AAGT class. The class was designed to allow such cars to compete with the best GT cars in the world. The 1975 season was launched with the new cars that would compete with the dominating Porsche Carreras. A very liberal set of rules allowed some body panels to be retained - the windshield, the rear window and the roof. Everything else was built from scratch.
Al Holbert saw the Monza's potential. By the end of the 1975 season, he had ordered a brand new car, prepared by Dekon Engineering built by Lee Dykstra. Chassis #1008 would be used starting for the 1976 season. In 1976 and 1977, he was the IMSA Camel GT Champion, beating Hans Stuck to Brian Redman to Peter Gregg. In Al Holbert successful 1977 campaign he captured another Camel GT crown. Unfortunately, it would be the last title for an American car. The Porsche 935s were becoming unbeatable right from the beginning of the 1978 season. However, the Dekon built Chevrolet Monza left its footprint on the IMSA Camel GT. They were quite unbeatable in 1976-1977. Chevrolet Monzas were to be seen in IMSA until 1986.