Its automobile platform, the Z-body, was developed entirely in-house at Saturn, and it shared very little with the rest of the General Motors model line.

It implemented a spaceframe design, used on the Pontiac Fiero during the 1980s, with non-load-carrying side panels made of plastic instead of metal.

Although nearly every year of the S-series's existence brought some minor changes to the architecture of the car, each model kept the same basic body styling throughout its respective production period.

The S series all used either the SOHC LK0/L24 or the DOHC LL0 version of the completely original, designed in-house Saturn 1.9L engine.

As a result, it's not uncommon for enthusiast-owners to swap a tall-geared MP2 manual into a car equipped with a DOHC engine for better fuel economy on the highway.

This type of door had previously been used in extended cab pickup trucks, but was an innovation in coupe design.

[3] The level 1 S-series equipped with a manual transmission were among the most fuel-efficient cars available in the United States when they were produced, reaching 40 miles per US gallon (5.9 L/100 km; 48 mpg‑imp) in EPA highway tests at the time (this would likely translate to 36 miles per US gallon (6.5 L/100 km; 43 mpg‑imp) under current methodologies).

Taiwan was selected as a way to test the car's competitiveness in what was a small, level market, with most international players present and with no significant domestic brands.

The first generation SL was constructed for the 1991 to 1995 model years, with the first Saturn rolling off the assembly line in the Spring Hill, Tennessee factory on July 30, 1990, the same day that then-CEO of GM, Roger Bonham Smith, retired.

On the inside, the SL featured a standard AM/FM radio with no cassette player and lower-grade cloth material on the seats.

The SL1 trim level added power steering, a passenger mirror, different hubcaps for the 14-inch wheels, an AM/FM cassette player, and softer cloth material on the seats.

Owners of the base model typically report real-world fuel mileage of about 38–41  mpg-US (6.2–5.7 L/100 km; 46–49 mpg-imp) on the highway with the manual transmission.

The 1990–1992 Saturn SC featured a DOHC 1.9-liter LL0 inline-four engine that was rated at 123 hp (92 kW).

The first generation SC2 had received a minor refresh in 1995 in which the lower front bumper and the vehicle's taillights were both updated.

The first generation SC1 coupe featured a SOHC 1.9-liter LK0 inline-four engine that was rated at 85 hp (63 kW).

[7] Saturn owner's manuals from this period made mention to the SL3- it would have featured an SC front end on an SL2 body, with all options as standard.

Beginning with all of the Saturn S-series vehicles that were made in late 1999 (sometimes referred to as 1999.5 models) had received improvements to both the SOHC and the DOHC engines in the S series.

Also introduced for the 1999 model year S-series vehicles that were sold in California was a different type of exhaust manifold that housed an upstream catalytic converter (this converter had heated up much faster than the conventional unit, and it had also decreased exhaust emissions faster as well), and it also had provisions for an air-injection reaction system (This had injected fresh air into the exhaust to reduce hydrocarbons during the startup of the vehicle, as it would help the oxygen sensors and catalytic converters reach their operating temperatures faster).

While retaining the previous generation's bodywork, it was facelifted with redesigned fascias front and rear, as well as new headlamps and tail lamps.

It had special Pearl White paint (a "silver-tint" pearl, shared with Cadillac models of this year), black Saturn emblems, spoiler, 15 in (381 mm) "teardrop" wheels, anti-lock four-wheel disc brakes, grey leather/cloth interior, rear headrests, fog lamps, and power locks and windows.

In 1998 and 1999, prospective buyers of a red or white SC2 had the option of purchasing the "Black Top Coupe Package" for $225.00 (US).

In 1999, a second Homecoming Edition was produced in a special "Mint Color" with tan leather interior, special off-white gauge faceplates, and black Saturn badges to commemorate the second "Homecoming" visit to the Spring Hill, Tennessee manufacturing facility.

The "Bumblebee Edition" included embroidered headrests, black leather interior with yellow leather inserts on the seats and door panels, black roof and mirrors, number designation inside the fuel filler door, and a certificate of authenticity.

There were also a limited number of Saturns that were exported to Japan as right-hand-drive vehicles circa between 1997 and 2000 (during the lifetime of the second-generation model).

Aside from having the steering wheel on the other side, Japanese market Saturns were also fitted with slightly different light units.

The rear lamps had amber turn signals and the front indicators were mounted closer to the corners rather than inboard.

As the Japanese had less money to spend on "luxury goods", as imported products are regarded, Saturn found very few buyers.

[citation needed] Saturn SCs competed in the SCCA World Challenge in the 1990s, winning several races from 1995 to 1997.