Engine, interior updates highlight 5-Series

German automaker BMW is at it again, changing the name of its six-cylinder-powered, midsize, luxury, 5-Series cars for 2008 to reflect larger, more powerful engines.

So, the 525i becomes the 528i, now with 230 horsepower, while the old 530i becomes the 535i with 300 horsepower.

In fact, the addition of the twin-turbocharged, 300-horsepower six cylinder to the 2008 BMW 535xi Sports Wagon makes it more powerful than the predecessor 540i wagon with 290-horsepower V-8.

BMW also updated the interiors of its early-for-2008 5-Series sedans and wagons and adds an optional Lane Departure Warning system that subtly vibrates the steering wheel when it detects a driver might be wandering out of his or her lane.

With annual sales of more than 50,000 in the United States, the five-passenger 5-Series cars are used both as family and business cars and rank as BMW's second most popular models, after the smaller, lower-priced 3-Series.

For 2008, 5-Series manufacturer's suggested retail prices, including destination charge, start at $45,075 for the base 528i. This is up from the $44,195 starting price for a 2007 525i.

But the 2008 starting price still is midway between major competing luxury sedans such as the 2008 Audi A6, which starts at $43,725, and the 2007 Mercedes-Benz E350, which starts at $51,325.

Buyers of the 5-Series sedan like the image that the BMW badge conveys -- of a four-door car that has a performance heritage, a good bit of technology and is anything but stodgy.

But while the 5-Series is a recommended buy of "Consumer Reports" magazine, it's not among the top vehicles in J.D. Power and Associates' Initial Quality Study that tallies problems in the first three months of ownership. In the 2007 IQS released this month, BMW ranked below average and below lower-priced brands like Chevrolet and Kia.

But it's worth mentioning that BMW owners also receive four years/50,000 miles of free maintenance that includes scheduled oil changes and even replacement of worn windshield wiper blades. This is in addition to a four-year/50,000-mile limited, bumper-to-bumper warranty.

It is easy to notice the newfound power in the 2008 BMWs.

The test 535xi could zoom forward after just a hint of a lag when the gas pedal was slammed down. I found the car moving aggressively to claim openings in traffic and bound up hills, though with a feeling of some heaviness and solidity attached.

The 535xi weighs in at nearly 4,000 pounds, which is about the same weight as a Chevrolet Colorado pickup truck, so this BMW doesn't feel lightweight or flighty. Peak torque of 300 foot-pounds can come on as low as 1,400 rpm and stay to 5,000 rpm, which is a satisfying range for any kind of driving.

The 3-liter, twin-turbocharged, double overhead cam, inline six cylinder with variable valve timing for both intake and exhaust functions is the same one put into the BMW 335i and adds a significant 45 horsepower and 80 foot-pounds of torque to the 5-Series vis-Ga-vis the previous engine.

It was mated in the test car to an updated, Steptronic automatic transmission that could be shifted manually, if I wanted, without clutch pedal.

Best of all, for 2008, the Steptronic is a no-cost option on all 5-Series cars, so drivers don't incur a charge to get it instead of a manual transmission.

And BMW has finally dropped its confounding and difficult-to-operate Sequential Manual Gearbox.

Power is increased -- to its highest ever -- in the base 5-Series car for 2008. Now called the 528i, it gets a 230-horsepower, 3-liter, double overhead cam, inline six cylinder with variable valve timing and no turbocharging. Peak torque is 200 foot-pounds at 2,750 rpm.

The top 550i sedan retains its 360-horsepower, 4.8-liter V-8.

Fuel economy isn't a highly touted characteristic of BMWs, but the tester performed within the government's ratings of 17 miles a gallon in city driving and 25 mpg on the highway, even though I didn't try to conserve fuel.

Handling, as expected in a BMW, was exceptional. The car body was well-controlled in all maneuvers, giving the feeling of it hunkering down securely over the wheels even over some busy road surfaces.

I didn't notice wind noise emanating from the exterior with its very subtle changes here and there. But I did hear road noise from the tires coming inside the car.

I appreciated the bigger door map pockets and better positioning of the window buttons inside the 5-Series on the door armrests. Other minor improvements include a flowing line of wood trim from the dashboard onto the doors.

The test car had optional, multi-contour seats that offer so many adjustment possibilities, it would be difficult to not be able to find a comfortable resting position.

Still, I continue to detest BMW's one-knob iDrive system for managing everything from navigation to ventilation. There are too many menus to be skipped through via the iDrive display screen.

With all-wheel drive, I never lacked traction, even on dirt-strewn pavement. Even non-all-wheel drive 5-Series cars come with standard traction control and stability control as well as frontal, curtain and front-seat, side-mounted air bags.

Beware the costly and lengthy list of options on these cars.

For example, leather upholstery, which you might expect to be standard in cars priced over $45,000, comes in option packages that start at $2,100.

And BMW's Park Distance Control, which warns drivers of obstacles in front and behind the car during parking, is a $700 option on all but the 550i and 535xi Sports Wagon.