What is Turbo Lag and How to Reduce it

With need for more power, lower emission and higher fuel effciencies, car manufacturer world over adopted turbo chargers to realise these benefits, however, with all things good you do have the other side too, so does turbocharges have their own inefficiencies and that's the turbo lag.

What is a Turbo Lag and how can one overcome it in a car?

What is Turbo Lag and How to Reduce it


Turbo lag is common with all engines using a turbo charger to boost power output of an engine, it's normally used in diesel engine wherein a naturally aspirated engine is more heavier, more polluting, have higher power losses and makes a diesel engine car more lethargic. Turbo charged engine are more fuel efficient, emit lower emissions and have better power output. Even a smaller sized turbocharged engine can deliver power figures equivalent of a much larger sized engine.

Turbocharged engines however have an issue of turbo lag. Time required to change power output  in response to throttle inputs is called Turbo Lag. Turbo lag manifests itself as a hesitation or slow increase in speed when we press the accelerator, the car seems to just stall and one feels quite helpless. This is due to the time needed for the exhaust system and turbocharger to generate the required boost. Load on the compressor, friction and inertia are prime contributor of Turbo Lag. Turbo lag can become a real cause for concern  when rapid changes in power are required  for example during overtaking.

Turbo Lag can be reduced in following ways:

Use lighter and smaller radius parts will allow faster spool-up, reduce rotational inertia of the turbocharger.

Change turbine aspect ratio.

Increase compressor discharge pressure and improve waste-gate response.

Reduce bearing frictional losses by using a foil bearing instead of conventional oil bearing.

Use Twin Scroll turbochargers or multiple turbos either in sequence or in parallel.

Antilag system can also help reduce lag.


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  • I experience the Turbo lag in my Duster 110 PS as well. I would really appreciate if somebody could tell me how to reduce it in a layman language. The reduction process as explained were bouncers to me.

    Ankan (1) reply