The 2004 Lexus IS 300 uses a 5-speed automatic transmission. In the United States for that model year, a factory manual option was not offered. The automatic is electronically controlled and paired with the 3.0-liter 2JZ-GE inline-6 engine, featuring adaptive shift logic and a manual/Sequential shift mode for driver control.
To understand this in context, the IS 300 of that era was part of Lexus’s first-generation IS lineup (the XE20 chassis). The powertrain pairing—2JZ-GE with a 5-speed automatic—aimed to deliver smooth, refined performance with user-selectable manual control, but not a traditional manual gearbox in the US market for 2004. Market variations exist in other regions, but the US 2004 model is automatic-only.
Key transmission facts
Below are the essential points about the IS 300’s transmission for the 2004 model year.
- The drivetrain uses a 5-speed electronically controlled automatic transmission.
- Engine pairing is a 3.0-liter 2JZ-GE inline-6, delivering balanced performance with the automatic transmission.
- The automatic includes a manual/Sequential shift mode, allowing the driver to select gears manually through the shifter or a contiguous manual-like control.
- In the United States, a factory manual transmission was not offered for the 2004 IS 300.
The above configuration reflects the common US specification for that year's IS 300. Some international markets historically offered different options and variants, but the US 2004 model year is defined by the automatic transmission with driver-manual shift capability rather than a traditional manual gearbox.
Market variations and notes
Across different regions, Lexus/Toyota has sometimes offered alternative transmissions in analogous models or earlier generations. While some non-US markets have seen manual variants in related Altezza/IS lines, the 2004 US IS 300 remained automatic-only in its standard configuration. If you’re buying a specific car, always verify the original window sticker or VIN-based documentation to confirm the exact transmission installed on that vehicle.
For those considering maintenance or a potential swap, consult a qualified Lexus technician. Transmission components, fluid type, and programming can differ between automatic generations, and any replacement or modification should preserve safety and reliability.
Summary
The 2004 Lexus IS 300 is equipped with a 5-speed electronically controlled automatic transmission, paired with the 3.0L 2JZ-GE engine. A factory manual transmission was not offered in the US for that model year, though manual options have appeared in other markets on related models. The automatic provides a manual-shift mode for driver engagement and continues to be a defining characteristic of the IS 300 in that era.