It used to be, you had to sacrifice performance if you wanted superior fuel economy. That was before the advent of the luxury hybrid, and BMW now offers a handful of them. The 2015 BMW ActiveHybrid 5 is the hybrid version of the midsize 5 Series sedan (reviewed separately). Its gasoline engine/electric motor drive system delivers a combined EPA fuel economy rating of 26 mpg, which is good but not great when you consider that most current compact cars have a combined rating in the low 30-mpg range. Yet this hybrid BMW 5 Series sedan also gallops to 60 mph in less than 6 seconds and fronts just about every luxury feature you could want.

Like most hybrids, though, the ActiveHybrid 5 takes a complicated path to achieve its particular blend of fuel efficiency and performance. If maximizing fuel economy is a chief priority, you'll find that there are quite a few more efficient and less expensive alternatives to the technically impressive 2015 ActiveHybrid 5. First, there's BMW's own diesel-engined 535d, which serves up a combined 30 mpg rating (not to mention a colossal 38 mpg highway performance), upholds the brand's performance promise and costs several thousand dollars less than the 2015 ActiveHybrid 5. BMW's 528i, the four-cylinder-powered sibling of the ActiveHybrid 5, is just a half-second slower to 60 mph, but delivers slightly better fuel economy and will save you a bundle.

Outside the BMW family, the diesel Audi A6 TDI is just as desirable and luxurious as the ActiveHybrid 5 in our estimation, and it has a 29 mpg combined fuel economy rating and standard all-wheel drive. The diesel-powered Mercedes-Benz E250 Bluetec, oriented for maximum efficiency and thus not quite a match in outright performance for the ActiveHybrid 5, balances the ledger with an excellent 33 mpg combined rating. And if you really want a hybrid, the Lexus GS 450h is certainly worth a look, given its 31 mpg combined rating.

Of course, the 2015 ActiveHybrid 5 is a fine luxury car that won't disappoint either a first-time BMW shopper or those who've had several BMWs in their garage. But unless having both a BMW and a hybrid are must-haves, you'll find that other luxury sedans offer better combinations of fuel economy, performance and overall value.

The 2015 BMW ActiveHybrid 5 is a midsize luxury sedan available in a single trim level. BMW's other 5 Series models are reviewed separately.

Standard equipment includes 18-inch wheels with run-flat tires, automatic adaptive headlights, LED foglights, automatic wipers, a sunroof and power-folding and auto-dimming heated mirrors. Inside the cabin, there's a power tilt-and-telescoping steering wheel, four-zone automatic climate control, leather upholstery and 10-way power front seats with four-way lumbar adjustments and driver seat memory functions.

Standard technology features for the 2015 ActiveHybrid 5 include BMW's iDrive control interface, a navigation system, voice recognition for most audio, navigation and phone functions, Bluetooth phone and audio connectivity, BMW Assist emergency communications, smartphone app integration and a 10-speaker sound system with a CD player, a USB input and HD radio.

The Luxury Line and the M Sport optional equipment groups incorporate upgraded leather upholstery, unique 18-inch wheel designs and other distinctive exterior and interior details such as specific wood trim. The M Sport package also includes several upgraded exterior components such as sport bumpers, a choice of performance or all-season tires and "shadowline" exterior trim, while inside there is a special steering wheel, dark gray interior wood trim and a matching headliner. The Luxury and M Sport packages also offer access to other added-cost items, like special paint colors and other customization choices.

More traditional options groups for the 2015 ActiveHybrid 5 include the Cold Weather package, which incorporates heated front and rear seats and a heated steering wheel. The Premium package adds a hands-free power trunk lid (opens or closes automatically when you pass your foot under the rear bumper with the key fob on your person), keyless ignition and entry and satellite radio. The Lighting package consists of LED adaptive headlights with automatic high-beam control.

The Luxury Seating package adds 20-way power front seats with ventilation and massage functions. The Driver Assistance package adds a head-up display, a rearview camera and front and rear parking sensors, while the Driver Assistance Plus package features numerous high-tech safety technologies (see the "Safety" section below).

There is no lack of other available premium features for the 2015 ActiveHybrid 5: Single optionsinclude the rearview camera, self-parking and night vision systems, wood steering wheel trim, self-closing doors, a power rear sunshade with manual rear side window shades, ceramic controls (try them and you'll find the extra cost is immediately justified), a 16-speaker Harman Kardon audio system, a 16-speaker Bang & Olufsen audio system, a rear seat entertainment system and some of the individual items from the options packages above. There's also BMW's "Individual Composition" collection, which consists largely of à la carte trim items.

The 2015 BMW ActiveHybrid 5 features a 3.0-liter turbocharged inline six-cylinder engine teamed with an electric motor, an eight-speed automatic transmission and rear-wheel drive. An extremely modest call for acceleration can have the ActiveHybrid 5 travel up to 37 mph propelled only by the system's electric motor; power for the motor comes from a lithium-ion battery located in the trunk. Total combined output of the gasoline engine and electric motor is 335 horsepower and 332 pound-feet of torque.

BMW estimates that the ActiveHybrid 5 will accelerate from zero to 60 mph in 5.7 seconds, essentially identical to times Edmunds testing recorded in both the regular 535i sedan (with an automatic transmission) and the diesel 535d.

Perhaps most important, EPA fuel economy ratings for the 2015 ActiveHybrid 5 are 26 mpg combined (23 city/30 highway).

Standard safety equipment for the 2015 BMW ActiveHybrid 5 includes stability and traction control, antilock disc brakes, front seat side airbags, side curtain airbags and active front head restraints. The stability control system integrates several features designed to improve braking performance, such as periodically wiping the brake rotors dry in wet conditions and automatically snugging the brake pads to the rotors when the driver abruptly lifts off the throttle. Also standard is the BMW Assist emergency communications system, which includes automatic crash notification, an emergency response button, remote door unlock and stolen vehicle recovery.

A rearview camera and parking sensors are optional. The comprehensive Driver Assistance Plus package adds speed-limit information, a forward collision warning and mitigation system (with pedestrian detection), a lane departure warning system, blind spot monitoring, driver drowsiness detection and side- and top-view cameras. Finally, the optional night vision system is capable of displaying possible hazards (including pedestrians) that might otherwise not be seen with the conventional headlights.

In government crash tests, the conventional 5 Series sedan earned a top five-star rating overall, including four stars for frontal impacts and five stars for side impacts. The Insurance Institute for Highway Safety awarded the 5 Series its highest score of "Good" in moderate-overlap frontal-offset, side-impact and roof-strength crash tests, but it earned only a "Marginal" rating in the institute's small-overlap frontal-offset crash test. The 5 Series' seat/head restraint design was rated "Good" by the IIHS for whiplash protection in rear impacts.

As soon as you get underway, it's clear BMW intends this car's hybrid powertrain mainly as a performance booster that also happens to add a modicum of efficiency enhancement. Hit the gas pedal at low to moderate speeds and the ActiveHybrid 5 jumps to your command, the wonderful inline six-cylinder engine revving with exceptional smoothness.

Although this particular BMW six-cylinder has long been regarded as a peerlessly refined gasoline engine, we're not totally fond of how the ActiveHybrid 5 blends gasoline and electric power. Demand for moderate power at lower speeds can elicit jerky responses as the system struggles to decide how to most efficiently respond. And although the ActiveHybrid 5 theoretically can drive solely on electric power up to suburban speeds, the reality is that the gasoline engine fires to life at even the slightest provocation.

Most drivers will appreciate the quiet and dense fashion in which the 2015 BMW ActiveHybrid 5 rides on almost all surfaces. The car comes standard with BMW's Driving Dynamics Control, which allows the driver to fine-tune the engine, steering and automatic transmission sensitivity based on defined settings. Even dialed up to the sportiest settings, though, the heavy ActiveHybrid 5 still feels oriented more for cruising than we'd prefer, underscoring the fact that it is far from BMW's sharpest-handling sedan.

BMW sees little reason that a hybrid model should be any different inside than its conventionally powered counterparts, so the 2015 ActiveHybrid 5's interior gives little evidence about its alternative powertrain. The ActiveHybrid 5 uses BMW's standard and effective dual-dial gauges with traditional orange night lighting. All the hybrid information you could ask for, however, can be found in the iDrive system's menus. The iDrive system itself has been improved over the years, and we now consider it one of the more straightforward human-machine interfaces you'll find in a vehicle at any price.

And just as in every other 5 Series model, you're treated to outstanding materials and meticulous build quality. The front seats are roomy enough for large frames, and the standard adjustable seats can be made comfortable for anyone, while the optional "multicontour" seats bring new meaning to comfort and support.

Even fairly tall occupants will find the rear seats of the ActiveHybrid 5 to be spacious and supportive enough for an all-day drive. But don't plan too many multi-passenger, weeklong trips: This car's battery pack squeezes trunk capacity to a meager 10 cubic feet, markedly tighter than the trunk of any nonhybrid midsize luxury sedan and significantly smaller than even the Lexus GS 450h, which offers 13 cubic feet.