Porsche 911 evolution

O-series — the original 911 (badged 901 until Peugeot's naming objection); air-cooled flat-six growing from 2.0 to 2.7L, culminating in the 1973 Carrera RS 2.7.

G-series — the impact-bumper era; introduced the 911 Turbo (930) in 1975 and the 3.2 Carrera and SC, plus the first factory Cabriolet.

Modernized 911 with coil-spring suspension, power steering, ABS and available Carrera 4 all-wheel drive; 3.6L air-cooled flat-six.

The last air-cooled 911; new multilink rear suspension and the twin-turbo 993 Turbo, widely seen as a high point of the classic shape.

First water-cooled 911; all-new platform shared with the Boxster and the controversial shared "fried-egg" headlights.

Return to round headlights; introduced direct fuel injection and the PDK dual-clutch gearbox in the 2008 facelift.

Longer wheelbase and largely aluminum body; the facelift moved the Carrera range to turbocharged flat-sixes.

Current generation with a full-width light bar, wider body across the range, and the first 911 hybrid (Carrera GTS T-Hybrid).