2026 Mazda Mazda3 Sedan

Skyactiv-G

2.5L Naturally Aspirated I4

A naturally aspirated four that breathes freely and rewards revs rather than relying on a turbo, delivering its torque with a linear, fuss-free responsiveness that suits Mazda's driver-focused ethos.

Part of Mazda's Skyactiv family launched in 2011, engineered in Hiroshima as the centerpiece of Mazda's holistic efficiency philosophy that re-thought the whole car rather than just chasing displacement.

• The Skyactiv-G was the first mass-production gasoline engine to reach a 14:1 compression ratio (detuned to 13:1 for North America), a figure usually associated with race engines.
• It uses an unusual 4-2-1 exhaust manifold to suppress engine knock, which let Mazda run that sky-high compression on regular pump fuel.
• Its pistons have a small cavity carved into the crown to control the flame and avoid hot spots during combustion.