GM Y platform
Encyclopedia
The Y platform, or Y body, designation has been used twice by the General Motors Corporation to describe a series of vehicles all built on the same basic body and sharing many parts and characteristics. The first was for a group of entry-level compacts
including the rear-engine Chevrolet Corvair
from 1960 to 1964 and conventional front-engine compacts built by GM divisions Buick
, Oldsmobile
and Pontiac
from 1961 to 1963. The second, and current, incarnation is used for a high-end rear-wheel drive automobile platform
from the 1980s through the 2000s.
The original Y bodies were:
Initially, each of the Y-body compacts from Buick, Olds and Pontiac were only offered as four-door sedans and station wagons when introduced in the fall of 1960 as 1961 models. In mid-1961, each of three divisions introduced two-door pillared coupes to the line with sportier versions of the Buick and Olds models added including the Special Skylark and F-85 Cutlass, both of which featured bucket seats, custom interior and exterior trim, and more powerful engines. For 1962, convertibles were added to the lineup by each of the divisions, with Pontiac also adding the sportier Tempest LeMans coupe and convertible to its compact lineup.
Also, the rear-engined 1960-69 Chevrolet Corvair
used a variation of the Y-body through the 1964 model year with a rear swing-axle suspension and a transaxle similar to that found on the 1961-63 Pontiac Tempest. The 1961-62 Corvair station wagons even shared the same roofline as the 1961-63 Y-body wagons. The Corvair would undergo major styling and engineering changes for 1965, when it switched to the new Z-body
. Chevrolet's front-engine compact, introduced as the Chevy II
for 1962 had some dimensions similar to the Y-body cars, but had a two-inch shorter wheelbase and was also shorter in length and width, its own X-body
platform which featured unit-body construction, single-leaf rear suspension and conventional in-line four- and six-cylinder engines.
Motor Trend
magazine named the Corvair as its 1960 Car of the Year, Tempest as 1961's Car of the Year, and the V6 Special received the award in 1962.
for the 1964 model year, which was shared with the Chevrolet Chevelle
. With the switch from a senior compact to an intermediate-sized platform, most of these "innovative" features were discontinued such as the Tempest's four-cylinder engine and transaxle, the aluminum block V8 (whose tooling was sold to Rover of England who improved the design enjoying considerable success with it as the Rover V8 in models such as the Rover P5B and Range Rover
) and the Olds Jetfire's turbocharged version of that V8. Also, the unit-body construction used in the Y-body cars was replaced by conventional body-on-frame construction for the A-body. The Buick V6 was continued and enlarged to 225 cubic inches with the basic engine remaining in production for many years, with a 3.8-liter or 231 cubic-inch displacement. The aluminum V8 was replaced by conventional cast-iron block V8s of 300 cubic inches for the Buick Special/Skylark and 330 inches for the Oldsmobile F-85/Cutlass, while Pontiac carried over its 326 cubic-inch V8 to the '64 Tempest/LeMans line while switching the base engine from the four-cylinder to a 215 cubic-inch inline six-cylinder.
Y bodies built after 1964 can be identified by the inclusion of the Y as the fourth character in the Vehicle Identification Number
, or VIN. Only two Y-body cars have been produced in this second group:
The Y-Body has a rear-wheel drive, front-engined V8 layout, accommodating either a small block Chevrolet V8 (such as an LT4 or LS1) in the Corvette, or the 32-valve DOHC Northstar V8 in the XLR. The Y-Body also has 4-wheel independent suspension. Like a standard rear-wheel drive, front-engined chassis, the Y-Body's V8 engine is longitudinally mounted, but unlike many such cars, the Y-Body incorporates a rear-mounted transaxle instead of a transmission mounted directly to the engine. Power is transferred to the transaxle via a torque tube. The transaxle is offered in both 6-speed automatic and 6-speed manual versions.
GM's Kappa platform
was inspired by the Y-body. The distinctive feature of both platforms is the backbone central-tunnel design.
Compact car
A compact car , or small family car , is a classification of cars which are larger than a supermini but smaller than or equal to a mid-size car...
including the rear-engine Chevrolet Corvair
Chevrolet Corvair
-First generation :The 1960 Corvair 500 and 700 series four-door sedans were conceived as economy cars offering few amenities in order to keep the price competitive, with the 500 selling for under $2,000...
from 1960 to 1964 and conventional front-engine compacts built by GM divisions Buick
Buick
Buick is a premium brand of General Motors . Buick models are sold in the United States, Canada, Mexico, China, Taiwan, and Israel, with China being its largest market. Buick holds the distinction as the oldest active American make...
, Oldsmobile
Oldsmobile
Oldsmobile was a brand of American automobile produced for most of its existence by General Motors. It was founded by Ransom E. Olds in 1897. In its 107-year history, it produced 35.2 million cars, including at least 14 million built at its Lansing, Michigan factory...
and Pontiac
Pontiac
Pontiac was an automobile brand that was established in 1926 as a companion make for General Motors' Oakland. Quickly overtaking its parent in popularity, it supplanted the Oakland brand entirely by 1933 and, for most of its life, became a companion make for Chevrolet. Pontiac was sold in the...
from 1961 to 1963. The second, and current, incarnation is used for a high-end rear-wheel drive automobile platform
Automobile platform
An automobile platform is a shared set of common design, engineering, and production efforts, as well as major components over a number of outwardly distinct models and even types of automobiles, often from different, but related marques...
from the 1980s through the 2000s.
First Y platform (1960–1964)
- Chevrolet CorvairChevrolet Corvair-First generation :The 1960 Corvair 500 and 700 series four-door sedans were conceived as economy cars offering few amenities in order to keep the price competitive, with the 500 selling for under $2,000...
(1960–1964) - Buick SpecialBuick SpecialIn 1962, the Special was the first American car to use a V6 engine in volume production; it earned Motor Trends Car of the Year for 1962. This 198 in³ Fireball was engineered down from the 215 and used many of the same design parameters, but was cast in iron. Output was 135 hp at...
(1961–1963) - Buick SkylarkBuick SkylarkThe Buick Skylark was a passenger car produced by the Buick division of General Motors. The model was made in six production runs. In each run, the car design varied dramatically due to changing technology and tastes, as well as new standards implemented over the years.-1953–1954:Introduced to mark...
(1962–1963) - Oldsmobile F-85 (1961–1963)
- Oldsmobile CutlassOldsmobile CutlassThe Oldsmobile Cutlass is a line of automobiles made by the Oldsmobile division of General Motors. The Cutlass began as a unibody compact car, but saw its greatest success as a body-on-frame intermediate car....
(1961–1963) - Oldsmobile Jetfire (1962–1963)
- Pontiac TempestPontiac TempestThe Pontiac Tempest was an entry-level compact produced by the Pontiac Motor Division of General Motors, introduced in September 1960 for the 1961 model year....
(1961–1963) - Pontiac Tempest LeMansPontiac TempestThe Pontiac Tempest was an entry-level compact produced by the Pontiac Motor Division of General Motors, introduced in September 1960 for the 1961 model year....
(1961–1963) - Pontiac LeMansPontiac LeMansThe Pontiac LeMans was a model name applied to compact and intermediate-sized automobiles offered by the Pontiac division of General Motors from 1962 to 1981. The LeMans was replaced by the downsized Pontiac Bonneville for the 1982 model year...
(1963)
Initially, each of the Y-body compacts from Buick, Olds and Pontiac were only offered as four-door sedans and station wagons when introduced in the fall of 1960 as 1961 models. In mid-1961, each of three divisions introduced two-door pillared coupes to the line with sportier versions of the Buick and Olds models added including the Special Skylark and F-85 Cutlass, both of which featured bucket seats, custom interior and exterior trim, and more powerful engines. For 1962, convertibles were added to the lineup by each of the divisions, with Pontiac also adding the sportier Tempest LeMans coupe and convertible to its compact lineup.
Also, the rear-engined 1960-69 Chevrolet Corvair
Chevrolet Corvair
-First generation :The 1960 Corvair 500 and 700 series four-door sedans were conceived as economy cars offering few amenities in order to keep the price competitive, with the 500 selling for under $2,000...
used a variation of the Y-body through the 1964 model year with a rear swing-axle suspension and a transaxle similar to that found on the 1961-63 Pontiac Tempest. The 1961-62 Corvair station wagons even shared the same roofline as the 1961-63 Y-body wagons. The Corvair would undergo major styling and engineering changes for 1965, when it switched to the new Z-body
GM Z platform
The Z platform or Z-body automobile platform designation was used on two different types of vehicles made by General Motors. The first was the second-generation Chevrolet Corvair from 1965 to 1969, which was a rear-wheel-drive and rear-engine compact car that replaced the previous Y-Body Corvair...
. Chevrolet's front-engine compact, introduced as the Chevy II
Chevrolet Nova
The Chevrolet Chevy II/Nova is a compact automobile manufactured by the Chevrolet division of General Motors produced in four generations for the 1962 through 1979 model years. Nova was the top model in the Chevy II lineup through 1968. The Chevy II nameplate was dropped, Nova becoming the...
for 1962 had some dimensions similar to the Y-body cars, but had a two-inch shorter wheelbase and was also shorter in length and width, its own X-body
GM X platform
There have been two X-body automobile platforms from General Motors. All X-bodies were small entry-level models.-Rear wheel drive:The rear-wheel drive X-body underpinned the Chevrolet Nova and similar cars of the late 1960s and 1970s. It was also the basis for the Cadillac Seville's K platform...
platform which featured unit-body construction, single-leaf rear suspension and conventional in-line four- and six-cylinder engines.
First Y platform innovations
The Y-body family of cars contained more innovative features than all other American products of that decade. Each model contained at least one notable advance:- Chevrolet Corvair featured a rear-mounted six-cylinder engine that included many aluminum components and an aluminum block, along with a rear swing-axle suspension and rear transaxle. The 1960 model Corvair also offered a gasoline-powered heaterGasoline heaterA gasoline heater is a small, mounted or portable, gasoline-fueled, space-heating device.In the United States they were used mainly for supplemental heat for the passenger compartments of automobiles and aircraft. Some aircraft continue to use gasoline heaters.-Operation:First, fuel is brought to...
as an option. - Buick Special and Oldsmobile F-85 for all three years shared an aluminum block 215 cubic-inch V8 engine featuring cast-iron liners to prevent overheating and block warpage problems common with aluminum block engines. Although Buick and Olds shared the same basic engine design, both divisions used different camshafts, carburetors and compression ratios. The 215 V8 was also available on the Pontiac Tempest for 1961 and 1962, but very few Tempests were so-equipped.
- For 1962, Buick introduced a new 198 cubic-inch V6 engine for the lower-line Special models in order to allow for a lower base price. That V6 shared many parts and dimensions with the aluminum V8 engine but featured a cast iron block. This was the first production V6 engine to be offered in a passenger car.
- Oldsmobile introduced a turbocharged version of the 215 V8 in mid-1962 for a special performance version of the F-85/CutlassOldsmobile CutlassThe Oldsmobile Cutlass is a line of automobiles made by the Oldsmobile division of General Motors. The Cutlass began as a unibody compact car, but saw its greatest success as a body-on-frame intermediate car....
called the Jetfire. This engine was among the first production turbocharged engines ever offered in a passenger car, the other being the Chevrolet CorvairChevrolet Corvair-First generation :The 1960 Corvair 500 and 700 series four-door sedans were conceived as economy cars offering few amenities in order to keep the price competitive, with the 500 selling for under $2,000...
's 164 cubic-inch six-cylinder introduced simultaneously for the Monza Spyder. The Olds Jetfire turbocharged V8 featured a four-barrel, 10.25 to 1 compression and was rated at 215 horsepower - one horsepower per cubic inch. - The Pontiac Tempest came standard with a 195 cubic-inch slant four-cylinder engine - then the only U.S.-built passenger car with such an engine. The Tempest four was really create from half a 389 cubic inch V8 block used in the standard Pontiacs. This engine, available with one- and four-barrel carburetion offered horsepower ratings ranging from 110 to 166.
- The Tempest also used a rear transmission, or transaxleTransaxleIn the automotive field, a transaxle is a major mechanical component that combines the functionality of the transmission, the differential, and associated components of the driven axle into one integrated assembly....
to permit a flat floor, eliminating the driveshaft hump, for improved interior space, while the Buick Special and Olds F-85 used a conventional front engine/front transmission drivetrain. * The Tempest also used an independent rear swing axle suspension similar to the rear-engine Chevy Corvair while the Buick and Olds compacts featured a conventional rear coil spring suspension. - For 1963, Pontiac replaced the Buick-sourced 215 aluminum V8 with a Pontiac built 326 cubic-inch V8 as the top power option for the Tempest. This 326 was based on the big Pontiac's 389 V8 and shared many of the larger engine's dimensions and components with horsepower ratings of 264 and 280. The '63 326 Tempest/LeMans served as a testbed for the 389-powered 1964 GTOPontiac GTOThe Pontiac GTO is an automobile built by Pontiac Division of General Motors in the United States from 1964 to 1974, and by GM subsidiary Holden in Australia from 2004 to 2006. It is considered an innovative, and now classic muscle car of the 1960s and 1970s...
that would be based on a larger and more conventionally engineered Tempest introduced the following year.
Motor Trend
Motor Trend
Motor Trend is an American automobile magazine. It first appeared in September 1949, issued by Petersen Publishing Company in Los Angeles, and bearing the tag line "The Magazine for a Motoring World". Petersen Publishing was sold to British publisher EMAP in 1998, who sold the former Petersen...
magazine named the Corvair as its 1960 Car of the Year, Tempest as 1961's Car of the Year, and the V6 Special received the award in 1962.
End of the first Y platform
Each of the Buick, Olds and Pontiac Y-body senior compacts were replaced a larger intermediate-sized platform called the A-BodyGM A platform
The General Motors A platform was a mid-size car automobile platform. The A-bodies evolved from rear wheel drive compacts, to rear wheel drive mid-size cars, to front wheel drive mid-size cars over the course of 32 years. The switch in drive layout in 1982 spawned the G-body...
for the 1964 model year, which was shared with the Chevrolet Chevelle
Chevrolet Chevelle
The Chevrolet Chevelle is a mid-sized automobile produced by the Chevrolet division of General Motors in three generations for the 1964 through 1977 model years. Part of the GM A-Body platform, the Chevelle was one of Chevrolet's most successful nameplates. Body styles include coupes, sedans,...
. With the switch from a senior compact to an intermediate-sized platform, most of these "innovative" features were discontinued such as the Tempest's four-cylinder engine and transaxle, the aluminum block V8 (whose tooling was sold to Rover of England who improved the design enjoying considerable success with it as the Rover V8 in models such as the Rover P5B and Range Rover
Range Rover
The Range Rover is a large luxury four-wheel drive sport utility vehicle produced by British car maker Land Rover. The model, launched in 1970, is now in its third generation...
) and the Olds Jetfire's turbocharged version of that V8. Also, the unit-body construction used in the Y-body cars was replaced by conventional body-on-frame construction for the A-body. The Buick V6 was continued and enlarged to 225 cubic inches with the basic engine remaining in production for many years, with a 3.8-liter or 231 cubic-inch displacement. The aluminum V8 was replaced by conventional cast-iron block V8s of 300 cubic inches for the Buick Special/Skylark and 330 inches for the Oldsmobile F-85/Cutlass, while Pontiac carried over its 326 cubic-inch V8 to the '64 Tempest/LeMans line while switching the base engine from the four-cylinder to a 215 cubic-inch inline six-cylinder.
Second Y platform (1984–present)
Vehicle identification number
A Vehicle Identification Number, commonly abbreviated to VIN, is a unique serial number used by the automotive industry to identify individual motor vehicles. VINs were first used in 1954...
, or VIN. Only two Y-body cars have been produced in this second group:
- 2004–2009 Cadillac XLRCadillac XLRThe XLR was a retractable hardtop convertible marketed by the Cadillac division of General Motors, assembled in Bowling Green, Kentucky. Intended to be Cadillac's flagship sports car, the XLR was based on the Chevrolet Corvette's Y platform...
- 1984–present Chevrolet CorvetteChevrolet CorvetteThe Chevrolet Corvette is a sports car by the Chevrolet division of General Motors that has been produced in six generations. The first model, a convertible, was designed by Harley Earl and introduced at the GM Motorama in 1953 as a concept show car. Myron Scott is credited for naming the car after...
The Y-Body has a rear-wheel drive, front-engined V8 layout, accommodating either a small block Chevrolet V8 (such as an LT4 or LS1) in the Corvette, or the 32-valve DOHC Northstar V8 in the XLR. The Y-Body also has 4-wheel independent suspension. Like a standard rear-wheel drive, front-engined chassis, the Y-Body's V8 engine is longitudinally mounted, but unlike many such cars, the Y-Body incorporates a rear-mounted transaxle instead of a transmission mounted directly to the engine. Power is transferred to the transaxle via a torque tube. The transaxle is offered in both 6-speed automatic and 6-speed manual versions.
GM's Kappa platform
GM Kappa platform
Kappa was General Motors' subcompact rear-wheel drive automobile platform for roadster applications. The architecture debuted in the 2006 Pontiac Solstice and 2007 Saturn Sky, and ended production in 2009....
was inspired by the Y-body. The distinctive feature of both platforms is the backbone central-tunnel design.