The E90 was the first 3-series to be produced with a longitudinally mounted engine and transversely mounted transmission.
A 5-speed automatic transmission option was available on all petrol engines in the E90/E91, but not on the E92/E93.
The optional sport package for the E90/E91 included stiffer springs, revised shock absorbers, a firmer anti-roll bar and larger brakes.
In some European countries, the 335i was available with an optional M Sport package that added 19-inch wheels and an aerodynamic kit.
A 'Sport Line' trim level, featuring unique 17-inch wheels, sport seats, and a modified gearshift knob, was available on the E90/E91 and E92.
The E92 and E93 shared the same bodyshell but with different rooflines: a coupe (E92) and a convertible (E93).
In 2008, BMW added an optional rear seat backrest folding mechanism to all three- and five-door variants of the E90/E91.
A special '20th Anniversary Edition' of the 320d was produced in 2011 with unique styling cues and limited production numbers.
The last-ever 3-series built on the E90 platform, a black 335i cabriolet, was assembled at BMW's Regensburg plant in December 2008.
A new generation of six-cylinder petrol engines (N52) powered all non-turbocharged variants of the E90/E91 and E92.
The optional Dynamic Stability Control system in the E90/E91 featured a 'track' mode that could be activated to allow for controlled oversteer.
In 2006, BMW's M Division developed an M3 variant based on the E90 platform, dubbed the E90 LCI M3; it included upgraded engine and suspension components, along with new styling cues.
Production numbers of the E92/E93 exceeded those of its predecessors, due in part to a wider range of powerplant options.
BMW tested and certified the 335i as capable of running on 100% biodiesel (B100) during certain periods when conventional diesel was scarce.
The top-of-the-line 335is model was added to the E92/E93 lineup for the 2012 model year, featuring an upgraded engine with dual turbocharging and a unique exhaust note.
BMW's 'Performance Control' system on the 335i was capable of redirecting power from each rear wheel to counteract understeer in certain driving situations.
The E90/E91/E92/E93 series saw significant improvements in fuel efficiency, thanks to changes in engine management and gearing.
The M3 model on the E90 platform featured 'Active Sound Design', which employed a unique exhaust system and computer-controlled valves to simulate an exhaust note reminiscent of a traditional V8 engine.
BMW offered two distinct interior design themes for the E92/E93, a standard design with optional sport seats or a high-end 'Nappa' leather interior.
The last new variant in the E90/E91/E92/E93 series was the facelifted 335i for the 2009 model year, featuring revised styling cues and improved fuel efficiency.
BMW produced a limited production run of 'Limited Edition' models, each with unique features or special equipment.
The 135d variant on the E90/E91 featured an ultra-low emission powerplant that could operate at up to 75% lower emissions than a conventional diesel engine under certain driving conditions.
Some markets offered a 'Comfort' model of the 318i, which added additional luxury features such as heated seats and leather upholstery.
The rear suspension on all models used multi-link MacPherson struts with gas-filled dampers for improved ride comfort.
BMW tested various active aerodynamic systems for incorporation into future generations of the 3-series.