You can almost visualize Homer Simpson salivating over these pictures. While they look like giant doughnuts, these circular snowballs are better known

One of the biggest keys to BMW’s success has been its consistency.

Price and position in the lineup mean little: Whether it’s the entry-level Three Series or the top-of-the-heap Seven Series, performance, handling and comfort are top drawer.

And no wonder. BMW actually has somebody on staff whose job it is to ensure just that kind of “BMW-ness” in all of its products. You might say he’s the protector of BMW DNA.

This month, I was lucky enough to drive two 2007 BMWs — a 525i and a 335i, both sedans.

The rear-wheel drive 525i sedan came equipped with a 3.0-liter, 215-horsepower in-line 6-cylinder engine, rated at 21 mpg in the city and 30 mpg on the highway. Standard equipment included the usual power assists, dynamic brake and stability control, traction control and alloy wheels. The final price was $49,315.

The rear-wheel-drive 335i sported the same equipment, along with brushed aluminum trim, moon roof, satellite radio, cold weather package and many other features. Final price was $46,645.

Not surprisingly, these cars have a lot in common.

Both are wickedly fast and handle like they invented the word. Driving them is a challenging, spine-tingling, yet satisfying experience. These cars get an almost absurd amount of power and energy from what seems on paper to be a relatively modest amount of horsepower.

But it’s the subtleties of these cars that sets them apart from just about anything else on the road.

For example, the steering wheel feels good in your hands: It’s the texture of the leather and the thickness of the rim and the way it snaps back quickly in turns and curves.

Responses to everything, from acceleration to cornering, is hair-trigger quick. And the braking leaves you with a feeling of utter invincibility because these cars stop on a speck of dust, let alone a dime.

Inside, there’s the satisfying snap and click to the turn signal and the “snick” of the gearshift. And of course, there’s also the aural experience: The sweet symphony of a top-drawer engine furiously at work resonates in your ears. It’s a marvelous combination of jet engine and Grand Prix race car, all concocted just for you.

No, these two cars are not perfect, of course. There’s cramped quarters in the rear seats, more so in the Three series than the Five series. The interiors come across as Spartan and quite Germanic to some eyes. The cruise control system is in a maddening location that sometimes causes you to engage it when you really want the turn signal.

And iDrive? Even after years of using this mouse-driven computer system, I still have trouble with it every now and then. Others just plain hate it.

The Three series is the car that basically defines the term “sports sedan.” Yes, it’s nicely appointed, but there’s no mistaking what this car is all about: performance. There are firm, supportive seats and not a bit of trim or glitz more than it needs. Gauges are, of course, simple and direct.

The acceleration with this twin-turboed, 6-cylinder, 3.0-liter, 300-horsepower demon is explosive, and it corners like a bobsled. Fuel economy was rated at 20 mpg in the city and 29 mpg on the highway.

After driving the Three series, I was surprised to find that the 525i felt almost sedate. This one’s the comfortable cruiser for the highway, the faithful companion on a long trip, the terrific sidekick for a long, casual drive over a varied and sometimes challenging course.

It’s got the suspension setup, the powertrain, and the interior comfort to make it the “go to” sports sedan for families who love road trips.

The styling of the Five series has been an issue since the current generation was introduced. It has held up well in my view, looking smart and contemporary. It is particularly handsome looking in a darker color.

The BMW Three and Five series sedans are land-going dreamboats if ever there were a pair.