How many other car manufacturers hew so consistently to their history and traditions, so much so that their owners have even developed their own distinctive language and nomenclature?

BMW owners refer familiarly to the “dual kidney grille” that adorns the front end of every BMW, as well as the “Hofmeister kink.” For non-initiates, that’s the forward bend in the base of the c-pillar that dates from a 1961 model and is named after former design director Wilhelm Hofmeister.

(There is also the “Bangle butt,” but that’s another story).

BMW may occasionally miss the mark when it strays from its core models (the $100,000 X6 springs to mind) but almost never with its bread-and-butter sedans. And no car is more representative of the BMW brand than the 5-series four-door. Built since 1972, it is now in its sixth generation. More than five million 5-series cars have been sold. With the all-new 2011 model, BMW’s tradition and values remain intact.

BMW junked the distinctive but chunky look of the 5’s predecessor and adopted a shortened version of the design of its popular 7-series, on which the 5 is based. The effect is to make the car look more sophisticated and elegant, but also less sporty.

The new 5 is 1.5 inches longer than the 2010 model, but the wheelbase has been stretched in excess of three inches, a more than reasonable trade off. With the extra length and additional equipment comes some extra weight. Acceleration, from zero to 60 miles per hour is a tick slower at 5.7 seconds but plenty fast for most purposes.

Fuel economy improves, despite the extra poundage. The 2011 with manual transmission gets 19 miles per gallon city/28 highway for a combined mpg of 22 versus 20 mpg for a 2010 car with a manual shifter.

The 5’s interior has received few changes. The familiar controls are in their familiar places: the shifter that clicks into gear rather than clunks, the easier-to-use iDrive dial, the steering- wheel-mounted cruise and communication controls.

The overall effect, combined with the restraint and impersonality of the trim, is one of efficiency at the expense of warmth and personality. BMW should sneak its designers over to Ingolstadt to see how Audi infuses some style into its instrument panels.

Equipped with the 3.0 liter turbocharged six-cylinder engine, my test car carried a base sticker price of a very reasonable $49,600. But when the bill for all the options, including the Milano Beige Metallic paint, came due, the as-tested price leaped to a less reasonable $65,425.

In an age when perfectly adequate after-market navigation devices are available for under $200, the $1,900 that BMW charges for a factory-installed system seems excessive. And for a company that considers seat assembly a core competency, it is surprising that heated and cooled seats aren’t part of the $2,200 Sport package.

One option worth the money is the $2,700 Option Handling Package. Keep the suspension set in the comfort mode, and the 5-series feels like any 4,000 lb. sedan: quiet, smooth, and powerful but uninvolving. But when you screw the suspension down two notches to sport, the shift points on the eight-speed transmission become tighter, and the car takes on a wholly different character: aggressive, noisy, and fun to drive.

That’s what BMW owners are looking for, and the 2011 5-series delivers. Expect it to generate more applications for membership in the club.