What does TD04 stand for in a turbocharger?

1. What is TD04?

Identity: TD04 is a series of turbochargers produced by Mitsubishi, 

encompassing several specific models.

Model Name Meaning (following Mitsubishi's naming conventions):

T: Turbocharger

D: Series code, a very classic and universal series.

04: Basic code representing the turbine housing size and specifications.

Key Features: The TD04 series is a typical small turbocharger. Its design goal is to provide quick 

throttle response and strong low-to-mid-range torque, rather than pursuing extremely high peak horsepower. 

This makes it very suitable for daily driving and small-to-medium displacement performance cars.

2. Common TD04 Models and Applications

TD04 is not a single model, but a family. What we commonly see are its specific sub-models, 

whose full numbers are usually similar to TD04L-13T, TD04HR-15TK, etc. 

These suffixes and numbers (such as L, HR, 13T, 15T) represent details such as the size of the compressor and turbine, 

and their interfaces.

This turbocharger is factory-installed in a vast number of vehicles, most notably:

Mitsubishi Lancer Evolution IV - IX: Generations 4-9 of the Evo used the TD05 series,

 but performance versions or market-specific variants also used the TD04.

Subaru WRX / WRX STI: This is one of the most famous applications of the TD04. 

Many generations of the Subaru WRX used the TD04 as the factory turbocharger.

Saab 9-3 / 9-5: Many Saab 2.0T models also widely used the TD04 turbocharger.

Volvo: Many older Volvo T5 models also used the TD04 series turbocharger.

Numerous other brands: Including some turbocharged models from Ford, Opel, and other brands.

3. Status in the Tuning Market

The TD04 holds a near-mythical status in the tuning market because:

Widely Available: Due to its widespread use in many vehicles, secondhand 

and refurbished parts are readily available at relatively low prices.

Huge Potential: For many small-displacement engines (such as Honda's B-series and D-series engines), 

swapping in a TD04 turbo is a highly cost-effective entry-level tuning option, easily achieving a significant power boost.

Fast Response: Its small size allows it to maintain excellent low-end torque response even after modification.

Conclusion

When you see the TD04, you can understand it as follows:

It is an extremely classic and universal small turbo series in Mitsubishi's turbocharger family, widely used 

by manufacturers in 2.0L performance cars from multiple brands such as the Subaru WRX and Mitsubishi Evo. 

It is also a highly cost-effective and popular choice in the tuning market.

It is a "must-learn" turbo model that almost every performance car enthusiast or tuning enthusiast will encounter.