Fiat TwinAir (two-cylinder)

0.9 L · inline-2 · turbocharged · petrol · 2010–present

Also known as: twinair, twin air, 0.9 twinair, sge twinair

Fiat's 875 cc two-cylinder — in the 500, Panda, Punto and the Alfa MiTo and Lancia Ypsilon.

A two-cylinder petrol engine in a modern car is rare enough to be the whole story, and everything about how it behaves follows from having two cylinders: it is inherently unbalanced, so what feels like a misfire or a mount problem on any other engine is often just the engine running.

Its distinctive technology is MultiAir, an electro-hydraulic system that opens the inlet valves through oil pressure rather than a cam lobe. That makes the oil part of the valve gear rather than merely a lubricant — and the MultiAir actuator unit is the engine's known expensive failure, giving a rough idle, a misfire and a loss of power that reads as ignition and is not.

⚑ The oil specification and interval are therefore not negotiable on this engine in the way they are on a conventional one, and a TwinAir that has been serviced late or with the wrong oil is the common version of a failed actuator.

Its real-world fuel consumption famously disappoints, and that is not a fault: a small engine worked hard uses what a larger one worked gently would.

Cars fitted with this engine

6 generations, across 3 makes. From the authored catalogue — an absent car means the catalogue has not reached it, not that the engine was never fitted.

Alfa Romeo

MiTo 955 2008–2018

Fiat

Lancia

Ypsilon 846 2011–present

Information, not instruction

CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.

Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.

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