1989-1994
Overview
Also called	Toyota Celsior (Japan)
Production	May 1989–September 1994
Model years	1990–1994
Designer	Kunihiro Uchida (1987)
Powertrain
Engine	4.0 L 1UZ-FE V8
Transmission	4-speed A341E automatic
Dimensions
Wheelbase	2,814 mm (110.8 in)
Length	4,996 mm (196.7 in)
Width	1,821–1,829 mm (71.7–72.0 in)
Height	1,405–1,415 mm (55.3–55.7 in)
Curb weight	1,705–1,750 kg (3,759–3,860 lb)

Lexus UCF10 is the internal name of the of the fall of 1989 built by the end of 1994 the first generation of the Lexus LS400 sold luxury-class sedan Lexus LS of the Japanese automobile company Toyota belonging brand Lexus .

With the Lexus 400, Toyota introduced the premium brand Lexus in October 1989 , initially only on the US market, with the model being offered in Japan in parallel as Toyota Celsior .The car and the new brand immediately proved to be successful, with over 42,000 vehicles sold in the first year - a value that the LS did not reach again until at least 2009.

A total of 169,000 first generation units were sold.

In August 1983, Toyota chairman Eiji Toyoda initiated the F1 project ("Flagship" and "No. 1" vehicle; alternatively called the "Circle-F" project), a clandestine effort aimed at producing a world-class luxury sedan for international markets. The F1 development effort did not have a specific budget or time constraints, and the resulting vehicle did not utilize existing Toyota platforms or parts. Instead, chief engineer Ichiro Suzuki sought to develop an all-new design, aiming to surpass rival American and European flagship sedans in specific target areas, including aerodynamics, cabin quietness, overall top speed, and fuel efficiency. During development, 3,900 F1 personnel built approximately 450 flagship prototypes and 900 engine prototypes and logged 2.7 million kilometres of testing on locations ranging from winter Europe roadways; deserts in Arizona, Australia, and Saudi Arabia; to U.S. highways and wilderness areas.

In late 1985, designers presented the first exterior study models to F1 management, featuring a sports car-like design with a low-slung hood and narrow front profile. By 1986, the sedan used a three box design with an upright stance, more prominent grille, and a two-tone body. Extensive modeling and wind tunnel tests resulted in a low drag coefficient for a conventional production vehicle of the time (C_d 0.29).For the passenger cabin, materials selection tests evaluated 24 different kinds of wood and multiple types of leather for two years before settling on specific trim combinations. By 1986, the Lexus marque was created to support the launch of the flagship sedan,and the vehicle became known as the Lexus LS. Following eight design reviews, subsequent revisions, and over US$1 billion in development expenses, the final design for the production Lexus LS 400 (chassis code UCF10) was approved in May 1987 with design patents filed on May 13, 1987.

In January 1989, the LS 400 made its debut as a 1990 model at the North American International Auto Show, in Detroit, Michigan. U.S. sales began in September 1989, followed by limited exports to Australia, Canada, and the United Kingdom. The LS 400's new 4.0 liter 1UZ-FE 32-valve V8 engine, capable of 190 kilowatts (250 hp) and 353 newton metres (260 ft·lbf) of torque, was linked to a new four-speed automatic transmission with electronically controlled shifts. The chassis used an independent, double-wishbone suspension setup, and an air suspension system was optional.The LS 400's 0–100 kilometres per hour (62 mph) time was 8.5 seconds, and its top speed was 250 kilometres per hour (160 mph).Compared to the rival target BMW 735i (E32) and Mercedes-Benz 420 SE (W126), the LS 400 had a quieter cabin, with 58 dB at 100 kilometres per hour (62 mph); a higher top speed; a lower drag coefficient and curb weight; and it avoided the U.S. Gas Guzzler Tax.

The LS 400 was among the first luxury sedans to feature an automatic tilt-and-telescoping steering wheel with SRS airbag, power adjustable shoulder seat belts, and an electrochromic rear-view mirror. The five-passenger cabin included California walnut and leather trim, power-adjustable seats, and soft-touch controls. A back-lit electroluminescent gauge cluster featured a holographic visual effect, with indicator lights projected onto the instrument panel. The memory system stored the driver's seat, side mirror, steering wheel, and seat belt positions. Available luxury options included a Nakamichi premium sound system and an integrated cellular telephone with hands-free capabilities. The LS 400 further contained some 300 technological innovations to aid smooth operation and silence, including fluid-damped cabin fixtures, vibration-insulating rubber mounts, airflow fairings, and sandwich steel body panels.

In Japan, the launch of Lexus was complicated by Toyota's existing four domestic dealership networks at the time of its introduction.The Toyota Crown and Toyota Century were exclusive to Toyota Store locations. During the LS 400's development, local dealers' requests for a Japanese domestic market version had grown, and a right-hand-drive Toyota Celsior-badged version was introduced shortly after the LS 400's U.S. debut, and introduced October 9, 1989 and only available at Toyopet Store locations The Celsior, named after the Latin word for "supreme", was largely identical to the LS. Models came in either basic "A", upgraded suspension "B", or fully equipped "C" trim specifications. The Crown and the Crown Majesta, which appeared later in 1991, were only available at Toyota Store locations which carried Japan-only Toyota luxury models, like the Century.

Adding incentive for early U.S. sales was a base price of US$35,000, which undercut competitors by thousands of dollars and brought accusations of selling below cost from rival BMW In December 1989, shortly after the LS 400's launch, Lexus ordered a voluntary recall of the 8,000 vehicles sold so far, based upon two customer complaints over defective wiring and an overheated brake light. All vehicles were serviced within 20 days, and the incident helped establish Lexus' customer service reputation. By 1990, U.S. sales of the LS 400 had surpassed those of competing Mercedes-Benz, BMW, and Jaguar models. Production of the first-generation LS 400 totaled over 165,000 units. Years after its introduction, the LS 400 remained a reliable choice for a used car, making Consumer Reports' 2007 list of recommended vehicles that regularly last 320,000 km (200,000 mi) or more with proper maintenance.

1992–1994

Debuting in September 1992 as a 1993 model, the refreshed LS 400(designed in 1991) was introduced with more than 50 changes, largely in response to customer and dealer requests. The vehicle received larger disc brakes, wheels, and tires, and adjustments were made to the suspension and power steering systems to improve handling. Stylistic changes included additional body side moldings and a revised grille, along with a greater selection of colors. For the interior, passenger front airbags, an external temperature gauge, digital odometer, seat belt pretensioners, and chlorofluorocarbon-free refrigerant were added. By 1994, the LS 400's U.S. base price exceeded US$50,000, a figure that had steadily risen since the vehicle's introduction. Customer demand for the vehicle and shifts in foreign exchange rates contributed to the increase in price. The growing popularity of the LS internationally was an asset to Toyota, as Japan had entered into an economic recession in 1991, that later became what was called the collapse of the Japanese asset price bubble or "bubble economy". Production of the first-generation LS ended in September 1994 to make way for production of the second-generation model in October.