Toyota UK has quietly introduced a dealer-installed power and drivetrain software upgrade for the first-generation GR Yaris, effectively bridging the gap between the original car’s performance and its successor’s.

While peak power remains unchanged at 257bhp, the ‘area under the curve’ has shifted thanks to a 20Nm increase in torque, bringing the total to 380Nm. While Toyota UK is yet to confirm, it’s safe to assume the engine software mirrors the one already available in Japan and Germany.

Where the standard car offers peak torque of 360Nm between 3,000-4,600rpm, the upgrade narrows the plateau to 3,200-4,000rpm. However, output remains higher across the entire 1,600rpm band, improving in-gear and roll-on response. In Japan, the upgrade makes a slightly higher peak of 390Nm, owing to the lack of a particulate filter in the exhaust. 

That will go some way to justifying the £995 asking price – as will the new drivetrain and throttle customisation modes. Alongside the performance bump, the software unlocks greater control over the GR Yaris’s advanced GR-Four all-wheel-drive system. Owners can now toggle between three torque splits – 55:45, 45:55, and a neutral 50:50. Electronic power steering gains selectable modes (Light or Heavy), and throttle response can be adjusted with three profiles: Original, Quick, or Control.

These drive modes represent a meaningful upgrade, but they don’t exactly mirror the torque distribution settings offered on the second-generation GR Yaris. That car features a more rear-biased 40:60 to 30:70 range as part of its revised GR-Four calibration – suggesting that while the new Gen I software adds welcome flexibility, it still operates within the limits of the original hardware.

In Japan, GR Yaris owners can go further by taking part in a “personalisation day”, driving three designated test courses – braking, slalom, and steady-state circle – under the guidance of Gazoo Racing engineers, who then fine-tune a customised driving mode based on individual characteristics.

The update is applied by trained technicians at authorised Toyota retailers and is offered as a “while-you-wait” service. For those enrolled in the Relax extended warranty programme, there’s peace of mind too – coverage remains valid for up to 10 years, unaffected by the upgrade.

The aftermarket was quick to respond with tuning options following the GR Yaris’s launch in 2020, but this marks the first time Toyota has offered an official performance upgrade of its own – and notably, one that doesn’t carry the badge of a tuning affiliate like TRD. The changes may be subtle, but for owners reluctant to make the jump to the more expensive second-generation model, the upgrade could prove a worthwhile investment.