The market for mid-size prestige has grown inexorably in the past quarter century, and while BMW itself now builds far smaller cars, the 3 Series remains the company's financial backbone, accounting for 40% of worldwide sales.

自1975年第一代3系列(其内部命名为E21，被狂热者所知)问世以来，宝马一直在努力，将威望和技术掌握融合到这个以前不太大的市场领域。在汽车公司将市场分割成无数的分支和分拆之前，3系列车完全位于一个简单等级的基础上：一家小型轿车，拥有更大、更贵的兄弟的品牌价值。在过去的25年里，中型汽车市场无情地增长了，尽管宝马自己现在生产的轿车要小得多，但3系车仍然是该公司的财务支柱，占全球销量的40%。当目前的模式推出时，它立即受到好评。因此，这一中年改革并没有彻底改变。尽管如此，随着奥迪(Audi)和梅赛德斯·查姆(MercedesChamping)等公司竞相在这一盈利领域取得胜利，宝马选择在新工程领域大举投资，以保持它们领先于日益激烈的反对意见。细微的差异和复杂的变化是显而易见的，通过更密切的检查，跨越范围。虽然跑车和敞篷车(后者的特点是快速可伸缩的硬顶，该公司第一次使用这种技术)有温和的风格更新，以提高他们的体育吸引力，最重要的新发展是肤浅的。考虑到即将出现的减排新目标，宝马已经投入了大量的专业知识，以使这款车型尽可能节能，这一任务最终导致了卓越的新320 d高效动力轿车。虽然并不完全是高端车型，但320 d生产智能汽车的排放水平，其燃油经济性几乎超过了市场上的每一种混合动力车。尽管该公司高调进军氢动力领域，并为其规模更大的汽车制造混合动力车，但3系扎哈哈迪德设计的莱比锡工厂的受人尊敬的人士已决定将重点放在改进柴油内燃机上。因此，320 d自鸣得意，拥有惊人的综合每加仑68.9，同时仍然踢出163 bhp，并在8秒内达到每小时62英里。十二个月前，这些数字会引起难以置信的呼声-甚至可能是巫术的建议。目前的3系列范围是广泛的能力，如果宁愿混合在信息。320 d是与强大的M3配对，仍然是市场上性能最好的汽车之一。布

Nonetheless, with the likes of Audi and Mercedes champing at the company's heels, vying for victory in this profitable sector, BMW have opted to invest heavily in new engineering to keep them ahead of the ever-encroaching opposition.  

 The 320d is paired with the mighty M3, still one of the best performance cars on the market.

Mindful of the looming new targets for cutting emissions, BMW has poured expertise into ways of making this model as energy efficient as possible, a task that culminates in the remarkable new 320d Efficient Dynamic Saloon.

While not exactly a high-end model, the 320d produces gets Smart-car levels of emissions, with fuel economy that trounces practically every hybrid on the market.

While the company has made high-profile forays into hydrogen-power and builds hybrid variants of its more sizeable cars, the esteemed folk at the 3 Series' Zaha Hadid-designed Leipzig factory have decided to focus on refining the diesel combustion engine

The 320d boasts an astonishing combined mpg of 68.9, while still kicking out 163bhp and reaching 62mph in 8 seconds

Since the inception of the very first generation 3 Series (known by its internal designation, the E21, by aficionados) in 1975, BMW has worked industriously to build a blend of prestige and technological mastery into this formerly modest market sector.  

But as the car market becomes ever more littered with brands, spin-offs, sub-divisions and new innovation (including BMW's own forthcoming Megacity concepts), the 3 Series represents the apex of traditional car-making, relatively conservative in form, technologically advanced, but never in your face 

 For all the high-profile bluster afforded to both sport- and eco-supercars, the ongoing success of this Bavarian mainstay shows that the conventional car still has a lot to offer. Provided, that is, the detail design is up to scratch.

Subtle differences and sophisticated alterations are evident on closer inspection across the range.

When the current model was launched, it was instantly acclaimed. As a result, this mid-life overhaul doesn't exactly scream radical change.

Although the Coupe and Convertible have mild styling updates to heighten their sporting appeal, the most significant new developments are under the skin.