Search our store

80 reviews


mTune SMARTflash m235 Upgrade [Mk8 Fiesta ST]

Kit Type

The new flagship mountune m235 power upgrade for the Mk8 Fiesta ST releases the ultimate potential from the ST's 1.5-litre 3-cylinder  EcoBoost engine, substantially yet safely raising power and torque output; improving performance and drivability, whilst adding a host of functionality, unique to mountune.

As with all mountune upgrades, it's had to pass our own stringent durability testing criteria, which included additional months of in-cylinder pressure monitoring to ensure engine robustness, whilst retaining all safety parameters, so you can have complete peace of mind that you're not just buying the best upgrade for your Fiesta ST, but also the most robust aftermarket calibration, too.

Peak power is increased to 235PS, whilst torque is uplifted to 350Nm but, as can be seen from the power graphs, it's the substantial increase throughout the rev-range and the way the torque is delivered that transforms the driving experience.

Working together with industry leading software and hardware teams has enabled the very latest technology available to be incorporated, taking mTune - and making it a whole lot smarter!

The mTune SMARTflash app allows you to easily DIY install and update calibrations to your ECU using nothing more than our app, the supplied Bluetooth OBD interface and your Smartphone; no laptop, no wires, no handsets, no problem!

m235 SMARTflash includes three calibrations, with unique functionality:

  • m235 performance
Increased power and torque (235ps / 350nm)
More aggressive launch control strategy
Enhanced audible exhaust output in Sport / Track modes
Optimised no-lift shift functionality
  • Stock performance
  • Anti-theft

In addition, the SMARTflash app, which is available for Apple and Android users, also allows for easy future calibration updates and includes a handy VIN and calibration ID reader as standard.

The m235 calibration has been fully optimised around the mountune induction kit, which itself delivers a 
1.5kPa pressure drop, allowing the engine and turbocharger to work more efficiently in achieving the increase in power and torque.

Induction noise is also boosted and, with an engineered approach that retains the OE appearance, the airbox provides a subtle improvement to engine bay aesthetics, whilst also capable of flowing enough air to support further, future increases in power output.

m235 is available in two versions that support all known regional variations and as it can be installed and removed anywhere in the world, at any time yourself, you could say the power's in your hands, quite literally!

  • mTune SMARTflash m235 upgrade
    (supplied with induction kit)
  • mTune SMARTflash m235 lite
    for owners that have already upgraded their induction kit)

What's in the box?

✓ smartflash obd bluetooth interface
✓ smartflash app (free download)
✓ aluminium dual entry-airbox
✓ high-flow panel filter
✓ porous lower air feed (hose)
✓ mountune zip-up case, info card and user guide

iphone shown for illustration, not included.

Our numbers don't lie

m235 delivers a substantial, yet safe increase in power and torque across the entire rev-range. 
genuine gains of up to 65nm and 36ps over the oe calibration transform the driving dynamic and in-gear performance and also allows the sprint from 0-60mph to arrive in just 5.9secs and knock well over a second off ford's standardised in-gear 31-62mph benchmark!

power output may vary based on individual vehicle condition, fuel grade and method of recording.

please note: all hardware is supplied as standard with a 12-month, 12,000-mile warranty against manufacturing defects.
installing the m235 calibration without the correct hardware may result in failure to achieve the quoted power / torque figures, abnormal running, detrimental fuel consumption or engine warning light illumination or, in extreme circumstances, damage to and / or failure of the engine. in any such instance no warranty is offered or implied by mountune.

by purchasing this product you agree for mountune to send you email about new updates or technical features relating to smartflash. you can opt out at any time.

Customer Reviews
5.0 Based on 80 Reviews
Write a Review Ask a Question
  • Reviews
  • Questions

Thank you for submitting a review!

Your input is very much appreciated. Share it with your friends so they can enjoy it too!

Filter Reviews:
    Lelard E.
    France France
    SmartFlash m235

    Very simply to install Just disappointed with the tax to import in France


    Thanks for your feedback - obviously we can't do anything about each countries import duty, but as you would've previously paid UK VAT @ 20% pre-Brexit, it actually works out a very similar overall price, you're just paying the tax to your country, rather than to ours.

    Jean-Christophe B.
    France France

    No problem, it's easy to install.

    Bernard P.
    Reunion Reunion
    Excellent upgrade

    Very happy with the upgrade. The fitting of the intake was very easy and the sound of the induction is quite noticeable now without the remap. I have fitted the M235 yesterday and I have to say this thing is beast. In conjonction with the chassis quality, I have the feeling of driving my old Integra type R with the Mugen ECU installed. The torque is quite impressive and the sound is nice even better with a Milltek exhaust. Thanks Mountune, I am very pleased for my purchase. PS: I only wonder if I need to use octane booster for my car since I live in a remote island of Indina Ocean (Reunion) where the gas quality is quite poor.


    Thanks for taking the time to leave such positive feedback, we're really pleased to hear how much you've enjoyed using our SMARTflash m235 upgrade. We leave all the factory knock detection strategy in place unlike some others, so if you add octane booster and it can take advantage of it, just as it would adapt itself the other way if you put a 95RON tank of fuel in it.