The Smart Roadster 371568 gear change improvement is one of the most debated topics in the 452 community. Owners upgrading to firmware version 1037371568 — colloquially called ‘371568’ — often report snappier, more confident shifts from the Softouch automated-manual gearbox. But is the improvement real, how large is it, and is the firmware change alone enough to transform the driving experience? This article examines exactly what the 371568 calibration changes, how it interacts with the Softouch transmission control unit, what earlier firmware versions did differently, and what realistic expectations you should have before reflashing your ECU.
Understanding the Softouch Gearbox and Why Firmware Matters
Before comparing firmware versions it helps to understand what the Softouch actually is. Unlike a conventional torque-converter automatic, the Softouch is an automated manual: a standard six-speed manual gearbox with electro-hydraulic actuators that operate the clutch and select gears in response to commands from the transmission control unit (TCU). The TCU and the engine ECU (Bosch MEG 1.1) communicate constantly — when a gear change is requested, the ECU must cut torque at precisely the right moment, hold the engine at the correct speed during the gear engagement, then restore torque smoothly once the new ratio is locked.
This handshake between ECU and TCU is governed almost entirely by software calibration tables. Even a modest revision to the torque-cut window, the rpm target during engagement, or the ramp-up rate after the gear is selected can produce a noticeable difference in shift feel. Earlier firmware versions were conservative — Smart’s engineers were cautious about drivetrain stress on a car they knew would be bought by enthusiasts who would push it hard. The 371568 calibration reflects lessons learned across the production run and represents Bosch and Smart’s final, most refined tune for the MEG 1.1 platform. To understand exactly how this ECU architecture works, our detailed breakdown of the Bosch MEG 1.1’s internal structure and calibration layers is essential reading before you attempt any firmware work.
What Exactly Changed Between Firmware Versions
Smart Roadster ECUs left the factory with several different firmware revisions throughout the 2003–2006 production run. The earliest calibrations — those found on 2003 and early 2004 cars — tend to have the slowest, most cushioned shift behaviour. The torque-cut window is long, meaning the engine power is suppressed for an extended period during each ratio change. The result is the characteristic ‘lurch and pause’ that many owners mistake for a mechanical fault.
Intermediate versions improved matters slightly, but the 1037371568 calibration introduced several meaningful refinements:
- Shorter torque-cut duration: The window during which the ECU suppresses engine output is tightened, reducing the ‘dead’ feeling mid-shift.
- Revised rpm matching targets: The engine speed the ECU aims for during gear engagement is better optimised for the 698cc three-cylinder’s torque curve, reducing the small speed bump or dip felt as the clutch re-engages.
- Faster torque restoration ramp: Once the gear is confirmed as engaged, power returns more quickly and with a steeper gradient, giving the sensation of a more decisive, purposeful change.
- Improved part-throttle shift logic: Earlier maps were tuned almost exclusively around wide-open-throttle behaviour. The 371568 calibration pays more attention to the light- and mid-throttle shifts that make up the majority of everyday driving.
The combined effect is a shift that owners consistently describe as 10–20 per cent quicker in perceived duration, with less of the spongy, indeterminate feel that characterises the earlier calibrations. That may not sound dramatic, but on a car whose gearbox is already a significant talking point, it makes a genuine qualitative difference to enjoyment.
How to Identify Which Firmware Your Car Currently Runs
You cannot determine your firmware version by looking at the car. You need an OBD-II reader capable of querying the Bosch MEG 1.1 — a standard ELM327 adapter paired with software that can read ECU identification data will show the calibration number. The string you are looking for is the software part number; if it ends in 1037371568, you already have the latest standard calibration. Anything else — common alternatives include earlier 371xxx suffixes or entirely different part numbers — means the car left the factory or was last serviced with an older map.
It is worth noting that if a previous owner had the car professionally remapped, the firmware string may have been altered by the tuner’s software. A custom map built on the 371568 base calibration is the preferred starting point for any performance work precisely because the shift logic improvements are already baked in. Starting a remap on an older base calibration and then porting across the gear-change tables is more complex and less reliable.
Real-World Owner Experiences and the Limits of Firmware Alone
Community feedback from forums including the Smart Roadster Club and various European owner groups is broadly consistent: owners who reflash to 371568 from a 2003–2004 calibration report a clearly improved shift character, particularly on upshifts under moderate to brisk acceleration. Downshifts — which involve a more complex engine-speed blip — also feel cleaner, though the improvement is less dramatic than on upshifts.
However, it is equally important to be honest about what the firmware does not fix. The Softouch is a fundamentally mechanical system, and worn actuators, degraded hydraulic fluid, or a clutch approaching end of life will not be cured by any software change. If your gearbox is slow even after a firmware update, the next diagnostic step is checking actuator operation and hydraulic pressure. The firmware improvement is most noticeable on a mechanically healthy gearbox — on a worn system, you may see little or no change.
It is also worth understanding that the smart roadster 371568 gear change improvement does not make the Softouch feel like a modern dual-clutch transmission. The shift times are still measured in hundreds of milliseconds rather than tens. What the firmware delivers is the best possible version of what the Softouch was designed to be — not a transformation into something it was never engineered to achieve.
Firmware 371568 as the Foundation for a Remap
For owners considering a full ECU remap — whether for power, torque, or both — the 371568 firmware is not just the preferred base, it is effectively the required base for any professional calibration work on the MEG 1.1. The improved gear-change logic means that when a remapper raises boost pressure and increases peak torque, the torque-cut and torque-restoration tables are already optimised to handle the higher loads. Attempting to run a high-power calibration on an older firmware base risks introducing clunky, aggressive shifts that stress the actuators and clutch.
Our own maps — from the BASIC 90 HP calibration through to the EVOLUTION 125 HP — are all built on the 371568 platform. If you are curious about what a remapped 452 can offer beyond the gear-change improvements, the full performance package details are here. The shift-quality benefit of the firmware is present at every power level; at higher outputs, the importance of having that clean torque handshake between ECU and TCU is amplified further.
Should You Update to 371568 Even Without a Full Remap?
Absolutely, yes — provided your car is in good mechanical health. Reflashing a Smart Roadster ECU to the 371568 firmware is a low-risk, well-documented procedure that delivers a measurable improvement in everyday usability at no mechanical cost. The process requires a compatible interface, the correct calibration file, and care to avoid interrupting the flash — but it is reversible, and there is no change to engine power or emissions compliance. Think of it as the software equivalent of replacing a worn component: you are simply restoring the car to the best version of its factory specification.
For context on the broader ECU landscape — including how the 256-byte EEPROM stores adaptive data that accumulates over the car’s lifetime and can itself affect shift behaviour — the MEG 1.1 technical overview covers the architecture in full.
Practical Checklist Before and After Flashing
Before the flash
- Verify current firmware version via OBD-II readout
- Check gearbox oil level and condition — dark, burnt-smelling fluid should be replaced first
- Confirm battery is fully charged; a voltage drop during flashing can corrupt the ECU
- Note any existing fault codes and clear them; some codes may recur after the flash and need separate investigation
After the flash
- Allow the ECU to complete at least two warm-up cycles before judging shift quality — adaptive tables need to reset and relearn
- Drive gently for the first 50–100 km to allow the transmission self-adaptation to build a baseline on the new calibration
- If shift quality is still poor after the relearn period, investigate mechanical causes: actuator seals, hydraulic pressure, clutch wear
- Re-read fault codes after 200 km of normal driving to confirm no new issues have emerged
The Smart Roadster 371568 gear change improvement is one of the most cost-effective upgrades available to 452 owners. It costs nothing in hardware, requires no mechanical disassembly, and on a healthy gearbox delivers a perceptible, consistent uplift in shift speed and quality that makes the Softouch substantially more enjoyable to use in daily driving. Pair it with fresh gearbox oil, verify your actuators are functioning correctly, and you will have the best-shifting version of the 452 that Bosch and Smart’s engineers were able to produce — an excellent foundation whether you plan to remap further or simply want a more satisfying standard car.
