BMW 528i xDrive Hits Home Run but Auto-Stop Strikes Out

BMWBMW bats .500 with the new fuel-saving technologies in its 2012 528i xDrive sport sedan.

That would get a wing of the Hall of Fame named after a baseball player, but it?s a ticket straight to the minor leagues for a $49,000-plus luxury car.

The midsize sport sedan is a great car in many ways, but the poor performance of its fuel-saving auto-stop feature grievously reduces its appeal.

Prices for the 2012 5-series start at $46,900 for a rear-wheel drive 528i with a 240-horsepower turbocharged 2.0-liter engine.

The all-wheel drive 528i xDrive raises the price to $49,200. All 5-series sedans have a fine eight-speed automatic transmission.

The four-cylinder engine, all-wheel drive and auto-stop systems are the 5-series? main changes this year.

The rear drive 535i features a 300-horsepower twin-turbo 3.0-liter straight-six and a base price of $52,500.

Add all-wheel drive for the 535i xDrive and the sticker rises to $54,800. The 550i comes with a 400-horsepower twin-turbo 4.4-liter V-8 and costs $62,000; the AWD 550i xDrive raises the tab to $64,300.

The well-equipped 528i xDrive I tested cost $60,250. It had metallic paint, specialty leather upholstery, navigation, a power trunk lid, 18-inch alloy wheels and many other options. All prices exclude destination charges.

The 528i?s powertrain is a wonder. The 2.0-liter engine?s 240 horsepower and 260 pound-feet of torque are more than the 2012 528i?s naturally aspirated 3.0-liter straight-six produced. It also uses less fuel and accelerates the car to 60 mph quicker; 6.2 seconds vs. 6.6 seconds.

The eight-speed automatic transmission shifts quickly and smoothly. The engine produces less power than competitors? V-6s, but the 528i?s power is more than adequate.

The 528i xDrive?s EPA ratings are outstanding. At 22 mpg in the city, 32 on the highway and 26 in combined driving, it beats by 4 to 6 mpg the combined rating of AWD sport sedans like the Audi A6 Quattro, Cadillac CTS, Infiniti M37x, Lexus GS 350 AWD and Mercedes-Benz E350 4Matic.

Unfortunately, one of the major enablers of that fuel economy is BMW?s poorly executed auto-stop system. It?s by far the car?s biggest flaw.

The system feels slower and more intrusive than the auto-stops on much less expensive cars like the 2013 Chevrolet Malibu Eco and eAssist-equipped versions of the 2012 Buick Regal and LaCrosse.

Auto-stop shuts the engine off when a vehicle stops moving for more than a few seconds. It?s becoming common as car companies look to improve fuel economy and reduce emissions. You can disable BMW?s auto-stop, but that eliminates the system?s contribution to the EPA combined fuel economy rating ? probably 3-4 percent.

Automakers program the system in varying ways, but they share the same goal: Don?t waste fuel idling at a traffic light, stop sign, etc.

The systems automatically restart the engine, too. That should happen in milliseconds, so the driver can move immediately, as if the engine had never shut down.

Automakers and suppliers have different names for the system: auto-stop, auto-start and stop-start, for example. Regardless of the name, they all aim to stop and restart the engine quickly and inconspicuously to save fuel.

The best systems shut off so smoothly the cars? occupants may not even notice.

BMW?s auto-stop feels neither inconspicuous nor quick. The two-ton 528i xDrive I tested shuddered every time auto-stop shut the engine off and again when it started. Restarts also felt slow.

The last system I tested, in the Chevy Malibu Eco, cranked the engine the moment I eased off the brake, assuring the car was ready to move by the time my foot reached the accelerator.

The 528i xDrive?s restart felt sluggish enough that I frequently caught myself reconsidering whether I had enough time to complete a turn or slip into traffic.

Note to BMW: People don?t buy your cars to worry about whether they can clear an intersection before the oncoming minivan arrives.

Aside from that frustrating problem, and a shortage of interior storage space common to all 5-series sedans, the 528i xDrive is almost perfect.

It?s roomy, fast, responsive, comfortable and very attractive.

The 101.5-cubic-foot passenger compartment is one of the largest among midsize sport sedans. The seats are comfortable.

The center console and map pockets don?t offer much storage room. The 14-cubic-foot trunk is smaller than what Audi, Infiniti, Lexus and Mercedes offer.

The 5-series? responsive steering, excellent handling and comfortable ride are unchanged from 2011. BMW?s voice recognition control for phone calls and the navigation system is very good.

In fact, nearly everything about the 2102 528i xDrive is very good. If BMW can fix the stop-start, it will be back in the big leagues pronto.

2012 BMW 528I XDRIVE:

?All-wheel drive five-passenger sport sedan

?Base price for 528i xDrive, excluding destination charge: $49,200

?Price as tested: $60,250

?Rating: Three out of four stars

?Reasons to buy: Fuel economy, performance, style features

?Shortcomings: Performance of auto-stop feature, interior storage

Source: MCT Information Services