Does the GS 400 have a 1UZ?
Yes—the Lexus GS 400 uses the 1UZ-FE 4.0-liter V8 engine.
In the late 1990s, Lexus offered the GS 400 as the V8-powered variant of the GS sedan. The 1UZ-FE is part of the Toyota/Lexus UZ family and was also used in the LS400 and SC400, providing the smooth, refined performance Lexus buyers expected from a luxury V8. As Lexus updated the GS lineup in later years, the brand shifted to different engines such as the 3UZ-FE in the GS430, and engine availability varied by market.
Engine lineage and model alignment
Key facts about how the GS 400 fits within the Lexus V8 lineup and the 1UZ-FE engine family are outlined below.
- The GS 400 was the V8-powered option in the early GS lineup and used the 1UZ-FE 4.0-liter V8 engine.
- The 1UZ-FE is part of Lexus's UZ family and was used in the LS400, SC400, and GS400 models of that era.
- In subsequent generations, Lexus transitioned to the 3UZ-FE-based GS430 for the higher end of the line, while the GS 400 designation largely disappeared as models evolved.
- Engine characteristics include a DOHC configuration with four valves per cylinder and an all-new design for its time, contributing to smooth power delivery and refined performance for a luxury sedan.
In summary, the GS 400 is indeed equipped with the 1UZ-FE 4.0L V8 in most markets, aligning it with Lexus's "UZ" V8 family across LS400 and SC400 as well.
How to verify in your vehicle
To confirm the exact engine in a particular GS 400, check the engine code on the block or the vehicle’s emission label. Look for the marking "1UZ-FE" on the engine itself, often on the valve cover or near the intake manifold. The VIN can also help; service manuals and dealer databases typically list the original engine code by VIN.
Notes on later GS generations
As the GS line evolved, Lexus introduced larger V8s and, in some markets, replaced the 1UZ-FE-powered variants. The GS430, for example, used a 4.3-liter 3UZ-FE engine, a distinct family from the 1UZ-FE. This evolution is part of Lexus's broader strategy to refresh the lineup with newer powertrains while maintaining a focus on luxury and performance.
Summary
Ultimately, the GS 400 did feature the 1UZ-FE 4.0-liter V8 engine in its era, sharing the engine family with the LS400 and SC400. As Lexus updated the GS lineup, newer variants adopted the 3UZ-FE and other powertrains, with market variations occurring across regions. If you’re researching a specific GS 400, verify the engine code on the block or label to confirm the 1UZ-FE configuration.
