Ford Mustang GT 5.0 V8 421hp Remap

The Ford Mustang GT 5.0 V8 421hp is a 5.0L naturally aspirated petrol engine producing 421 BHP and 542 Nm from the factory. With a typical Stage 1 remap, output increases to approximately 441 BHP and 562 Nm — a gain of around 20 BHP (5%) and 20 Nm (4%).

This engine has low remap suitability, though the available headroom is limited, so gains are modest compared to higher-output variants. The tuning headroom is classified as limited, based on the percentage gain available from the factory output.

Considerations: Naturally aspirated engine: gains are usually limited; results vary widely.. High tuned torque: check transmission torque capacity and service history.

All figures shown are typical estimates based on aggregated Stage 1 data for this engine variant. Actual results depend on vehicle condition, mileage, and the chosen tuning method. We recommend discussing your specific vehicle with a qualified remap professional.