The 1KR series uses aluminium engine blocks and chain driven DOHC cylinder heads.

The engine was also adapted to meet European emission standard EU6 and can have CO2 levels as low as 88/89 g/km in Toyota Aygo or Citroën C1/Peugeot 108 since 2014 in NEDC.

[10] New 1.0-litre VVT-i engine is lighter & compact for better fuel consumption, better performance, reduced vibration & noise level.

Perodua claims ECE fuel consumption figures of 22.8 km/L (64 mpg‑imp; 54 mpg‑US) for the manual variant and 21.3 km/L (60 mpg‑imp; 50 mpg‑US) with the automatic, both exhibiting a 1.2 km/L (3.4 mpg‑imp; 2.8 mpg‑US) improvement over the old 1KR-DE2.

The new 1KR-VE engine now features variable-valve timing with intelligence (VVT-i) on the intake valves.

Several minor changes and refinements were also introduced for increased fuel efficiency and more linear power delivery.

The engine was modified to meet the Euro 6.2 emission standard[11] whilst boosting performance to 73 PS (54 kW; 72 bhp) and economy up to 58.8 mpg on combined WLTP cycle while keeping emissions at 110 g/km co2 on WLTP cycle.