The current 3 Series, already strong on BMW dynamism and identity, now gains an additional measure of both by virtue of discreet updates and refinements. At the rear, a widened track enhances these vehicles' planted-on-the-road stance; careful and subtle modifications to the front, sides and aft end make the total design even more harmonious.

At the front. A new, bolder front spoiler/bumper ensemble imparts sportier, stronger character. Its center air intake is larger than before, enhancing the air supply for mechanical components; upswept lines in the lower air intakes, the bumper itself and the newly shaped headlight clusters emphasize the wide stance. Double longitudinal hood lines, more 3-dimensional than ever, rise toward the A-pillars and frame the hood's power dome. New lighting features include the layered turn-signal lenses, and on models with Xenon Adaptive headlights, BMW's distinctive luminous rings now serve as Daytime Running Lamps (on all models, they also function as parking lights). The optional Park Distance Control now includes front and rear monitoring.; formerly PDC was offered on the 3 Series in a rear-only version.

In profile. The lower character line that runs from just behind the front wheel well to just ahead of the rear wheel well, is more prominently contoured and strongly expresses the low stance. On Sport Package-equipped models, new high-gloss Shadowline (black) trim more elegantly frames the side windows. And new wheel designs freshen the 328i models' 16-in. and the 335i/335d models' 17-in. standard equipment.

At the rear. Restating BMW's traditional L-form are the taillight clusters of both Sedan and Sports Wagon models. Their two main segments, for the taillights and turn signals, are composed of LED rows for an even higher-tech look than before. On Sedans, the trunklid is newly shaped to go with the new taillight design. And the 0.6-in.-wider rear track does its part to strengthen an already road-gripping stance.

New colors. BMW paint colors are notable for their richness and eye-catching appeal. A total of 12 colors are offered with three new metallics for '09: Space Gray, Tasman Green and Blue Water.

Interior: newly refined materials, surfaces and colors. Here too, subtle updates and refinements mark the newest 3 Series Sedan and Sports Wagon interiors. Materials and surface quality add appeal; certain functional elements including the optional iDrive controller and climate and audio controls offer refined appearance and tactile qualities.

The doorsill trims with their distinctive BMW script are new. The somewhat smaller iDrive controller has a fine galvanic surface, and is newly surrounded by the direct-select keys that enhance iDrive's user-friendliness. There's a larger storage tray in the center console including the auxiliary audio input and providing an appropriate place to lay an audio source. Door-panel design has been refined too; on the driver's door the power-window and -mirror controls have been moved 2 cm rearward for an easier, more natural reach.

Colors and color contrasts have been improved, as well. Three new colors for the optional Dakota leather upholstery are offered: Oyster, Saddle Brown and Chestnut Brown. Interior trim choices are updated, too, with a new Fine Line aluminum trim replacing the former brushed aluminum and Light Burl Walnut replacing Light Poplar among the available wood trims.

Lastly, a heated steering wheel - much appreciated by drivers of other BMW Series in winter weather - has been added to the optional Cold Weather Package for all models.

In general, the interior space - with its attractive interplay of convex and concave surfaces, its sporty elegance and technology-oriented esthetics is more appealing than ever.

BMW Efficient Dynamics in the new 3 Series: BMW Advanced Diesel with Blue Performance meets emission standards in all 50 states.

• New inline 6-cylinder twin-turbo diesel engine in 335d Sedan.
• BluePerformance technology meets diesel-engine emission standards in all 50 U.S. states.

In its competitive field, BMW is known for powertrains that achieve an outstanding combination of performance and fuel efficiency. In addition to the commendable mileage ratings of the 3 Series' gasoline engines, the newest evidence of BMW's EfficientDynamics approach is the new twin-turbo diesel engine of the likewise new 335d Sedan model, which combines the new-age diesel performance that has swept European motoring in recent years with truly remarkable Miles per Gallon.

The new 335d Sedan: power, torque and remarkable fuel efficiency. All with refinement and sound worthy of a BMW.

In Europe, where fuel prices have historically been - and remain - much higher than in the U.S., vehicle manufacturers have achieved dramatic gains in the performance, smoothness, quietness and emission control of diesel engines…while maintaining the diesel's historic superiority in fuel efficiency. Now, with the new 335d Sedan, BMW brings this progress to the U.S., with brand-new technology that meets the U.S.' strictest emission standards.

Like all '09 BMW gasoline engines, the 335d's new diesel is constructed with a weight-saving aluminum cylinder block - something that's not taken for granted given the diesel's much higher compression pressures. (All BMW engines have aluminum cylinder heads.) It is an inline 6-cylinder engine maintaining a defining BMW tradition that means exceptional smoothness and unique sound.

In addition, several diesel-specific technologies of this new engine contribute to its achievement of true high performance, diesel fuel economy and clean exhaust:

Common-rail direct fuel injection. One of the most important innovations of recent diesel development, this has replaced the individual-cylinder or distributor-type injection systems of earlier diesel engines.

Common Rail (CR) means that a single, very high-pressure fuel-delivery pump supplies all cylinders, the fuel traveling along a common "rail" or distributor line. From there, fuel is injected at extremely high pressure (180 bar/2645 lb./sq in.) directly into the cylinder.

The basic novelty of common-rail injection was to divorce the production of fuel pressure from the actual injection process; this was necessary to give the diesel engine what gasoline engines have long had, namely completely electronically controlled fuel injection. CR also facilitates multiple injections per combustion cycle. In all, this was a breakthrough that made possible dramatic strides in diesel power, efficiency and emission control.

Piezo injectors. A further breakthrough, already applied by BMW in the 335i (and other BMWs) models' twin-turbo gasoline engines. With direct injection, the injectors - that critical component injecting fuel into each cylinder's combustion chamber - are subject to especially high temperatures and pressures. Instead of most injectors' conventional electrical valves, a "stack" of piezo crystals reacts lighting-fast to impulses from the engine electronics governing the injector needle's opening stroke and duration for ultra-precise control. This, too, facilitates major advances in fuel economy and emission control, in gasoline, as well as diesel engines.

Variable Twin Turbo technology. In contrast to the two small, equal-size turbochargers of BMW's twin-turbo 6-cylinder and V-8 engines, the diesel employs two turbos of different sizes.

At low engine speeds, intake air does pass through the large turbo, but it's the smaller, lower-inertia one that does the air compressing (turbocharging). Thanks to its optimum efficiency within this rpm range, it provides effective boost for driving from a standstill up to modest acceleration rates and driving speeds. So it is that this engine develops a good 390 lb-ft. of torque at as low as 1500 rpm - a remarkable achievement that will amaze first-time 335d drivers and continue to thrill those who drive this BMW regularly.

With increasing engine speed, the larger turbocharger begins to take over: first as a pre-compressor for the smaller one, then progressively until it becomes the primary turbo. The engine reaches its maximum of 425 lb-ft. by 1750 rpm, then maintains this immense torque level until 2250 rpm going on to reach its peak power of 265 hp at 4200 rpm.

Diesel combustion, power and torque characteristics. In its most basic distinction from gasoline engines, a diesel engine achieves its combustion not with a sparkplug, but by much "harder" compression of the fuel-air mixture; the 335d engine, for example, has a compression ratio of 16:5:1, vs. 12.0:1 in today's ultra-high-performance BMW M gasoline engines and the 10.2:1 of the 335i twin-turbo gasoline unit. For one thing, this requires a significantly stronger engine structure; indeed, the 335d engine weighs more than its 335i counterpart.

The diesel combustion process also produces very different torque and power characteristics. Whereas the 335i engine reaches a maximum torque of 300 lb-ft. @ 1400-5000 rpm and a maximum power of 300 hp @ 5800 rpm, the 335d attains its maximum torque of 425 lb-ft. @ 1750-2250 rpm and its maximum power of 265 hp @ just 4200 rpm. In general, diesels have this low-speed-torque, lower-rpm character and in their vehicular application, they are geared differently. The 335d, for example, comes only with automatic transmission - an automatic is the ideal partner for a diesel engine - and its final drive ratio is 2.81:1, vs. 3.46:1 for the 335i with automatic transmission.

Diesel engines also employ a different fuel, the product of a different refining process from that of gasoline. The two fuels are not interchangeable; gasoline cannot be used in a diesel engine, and vice versa. Their prices typically diverge; at any time or in any location, demand may be different for the two, and government taxation policies for gasoline and diesel fuel also diverge.

Stellar pulling moxie, full-bore acceleration - and fuel efficiency. The huge torque output of 425 lb-ft. at relatively low engine speeds speaks for itself; 335d drivers will marvel at this engine's robust response at low to medium speeds. The peak power output of 265 hp also speaks for itself, as does the resulting 0-60-mph time of 6.0 sec. While official EPA mileage estimates are not yet available, preliminary tests indicate 23 mpg city and 33 highway.

Most advanced exhaust gas management: SCR catalyst with AdBlue injection.

BMW Advanced Diesel with BluePerformance optimizes emission management by incorporating an oxidation catalyst placed close to the engine, a diesel particulate filter housed in the same unit, and an SCR catalyst with urea injection. Apart from filtering out even the smallest particles from the flow of exhaust gases, this combination ensures effective reduction of nitric oxides (NOX) by way of a chemical reaction within the exhaust system initiated by the injection of a small dose of urea referred to as AdBlue. The ammonia (NH3) generated in this process within the SCR catalyst subsequently converts the nitric oxides (NO and, respectively, NO2) in the exhaust gas into environmentally compatible nitrogen (N2) and vapor (H2O).

BMW has developed a two-tank system for AdBlue ensuring convenient use of this new technology with all the benefits and ease required by the customer: The amount of AdBlue required in each case is drawn from the active tank comprising approximately 1.6 gallons by means of a dosage pump. And since the urea solution would freeze at a temperature of ?11oC, this active tank, as well as the dosage pipes are heated.

AdBlue technology by BMW: reduced emissions without additional service appointments.

The active tank is connected to a second reservoir, the so-called passive tank. With its additional capacity of approximately 4.5 gallons, this passive tank offers a plentiful supply of the urea solution required within the car. The average range provided on this supply capacity is indeed sufficient to have the tank system replenished as part of normal scheduled maintenance.

From the active tank AdBlue is delivered to the dosing valve and atomized into the exhaust emissions. Consistent distribution of AdBlue within the flow of exhaust emissions is ensured by the SCR mixer. The ammonia generated in this way in the hot emission gas subsequently acts in the SCR catalyst as a reduction agent and converts environmentally harmful nitric oxides into nitrogen and water vapor in a process referred to as selective catalytic reduction.

This process gives the special SCR catalyst its name with the SCR system as such being masterminded by highly efficient engine management. A nitric oxide sensor, finally, provides information on the concentration of NOX in the exhaust emissions.

The large amount of AdBlue provided in the reservoir enables the customer to go on driving as before without having to change service intervals or observe any particular requirements, thus benefiting from the advantages of this environmentally friendly emission technology throughout the entire running life of the car without any additional service or visits to the workshop. During the first four years or 50,000 miles, the replenishment of AdBlue will be covered as part of the BMW Scheduled Maintenance program: not only will there be no additional inconvenience, but no addition cost during that period.