The eAssist hybrid delivers both real economy and performance.
Chevrolet Malibu Eco
By: Police Fleet Manager Staff
Introduced in January 2012 as a 2013 model, the eighth generation Malibu is a totally new midsize sedan. The impressive upgrades in powertrain, exterior styling, interior comfort and fuel economy place it solidly into the world-class; fully equal to the Ford Fusion, Toyota Camry and Honda Accord. The new Malibu, in general, and the Malibu Eco, in particular, is an excellent choice for non-police-package police admin use. The Malibu Eco might be, in fact, perfect. It fits the admin need and has a legit green glow.
We covered the first generation 2009 Malibu Hybrid in the Jan-Feb 2009 issue of Police Fleet Manager…and were not impressed. That generation of Malibu was physically smaller; OK for plainclothes, not OK for uniformed use. Also, that first generation of BAS mild hybrid gave just a 2 mpg improvement over the non-hybrid engine. Many midsize sedans gave mileage just as good. This new Malibu Eco is totally different…and we are impressed, very impressed.
The NextGen Malibu has two major changes: the sedan itself has grown roomier, and the hybrid drivetrain on the Eco version is much more fuel efficient and powerful. First, the hybrid drivetrain.
eAssist Hybrid Drivetrain
The 2013 Malibu is available in two drivetrains: a 182 hp 2.4L eAssist I4, and a 197 hp 2.5L I4. (A 259 hp 2.0L turbo I4 is on the way.) GM’s new eAssist mild hybrid was first introduced on 2012 Buick LaCrosse and Regal.
The eAssist is a Gen 2 version of GM’s mild hybrid called a Belt Alternator Starter (BAS) system. A so-called “mild” hybrid is very different from the “full” hybrids that use the electric battery and motor to propel the car under a wide variety of conditions. The Malibu eAssist mild hybrid technology is basically a stop-start system combined with an electric motor that “assists” the gas engine under hard acceleration. The motor/generator provides electric-only operation only at very low speeds and under very low throttle.
The electric motor portion of the drivetrain uses a belt-driven, liquid-cooled electric motor/generator. This is connected to a 115-volt, air-cooled, lithium-ion battery pack. The electric motor is both bolted to the engine and also connected to an engine pulley with a belt. This works both ways. The gas engine powers the electric motor, which acts like a generator to charge the battery. The battery powers the electric motor, which acts like a starter motor to start the engine. (Think rope-pull lawn mower.)
The eAssist motor is rated at 15 hp and 79 lb-ft of torque. The 2.4L four-cylinder engine is rated at 182 hp and 172 lb-ft of torque. You can’t add the two together to get 197 hp, but the electric motor does indeed help acceleration. It is more than just a massive starter motor. You cannot feel the electric motor kicking on or off. The eAssist motor “helps” the gas engine at all vehicle speeds. The key word here is “assist.” The gas engine does all the heavy lifting. The electric motor only “helps.”
The electric motor/generator replaces the standard alternator. The engine shuts off (Auto Stop) as the driver takes his foot off the gas and slows to a stop—whether or not the brake is used. The engine remains off in Drive with the brake applied, preventing idle time. Then it re-starts as soon as the brake pedal is released, as the driver’s foot moves to the gas pedal. There is the slightest delay between the brake pedal being released and the car moving forward, but it is easy to get used to. When the engine is shut off, an electric oil pump keeps the transaxle up to pressure and ready to go.
BAS Hybrid Versus eAssist Hybrid
There are many differences between the Gen1 BAS hybrid in the old Malibu Hybrid and the Gen2 eAssist hybrid in the new Malibu Eco. First, the new electric motor is much larger. It produces 15 hp of assist, instead of a mere 2 hp of assist. It generates 15kW of regenerative braking instead of 5kW. The belt-drive system has been upgraded and redesigned to handle more loads both ways. A lithium-ion battery pack now replaces the nickel-metal battery pack.
The original BAS hybrid used a 164 hp 2.4L I4 engine and a 4-speed auto. The eAssist hybrid is based around a 182 hp 2.4L I4 engine. A 6-speed trans replaces the old 4-speed trans. This new trans gives better first and second gear ratios for take-off and bottom-end acceleration. This also gives more efficient gear ratios (fifth and sixth) for better fuel economy while cruising.
Finally, the eAssist system allows the Malibu Eco powertrain to use a much lower (numerically) final drive ratio, 2.64 versus 3.05. This allows the engine to turn at lower rpm at all vehicle speeds. The combination of a more powerful engine, a three times more powerful electric motor to “assist,” and a wider selection of gear ratios from the 6-speed allowed this huge change to the final drive ratio.
All this adds up to the only thing that matters: better fuel economy under all conditions. The EPA City rating has jumped from 19 mpg to 25 mpg. The EPA Highway estimate has increased from 30 mpg to 37 mpg. Put another way, the 2008-2010 Malibu with the original BAS mild hybrid gave a modest 2 mpg improvement in both City and Highway over the non-hybrid Malibu. The Gen 2 eAssist gives a solid 6 mpg increase in both City and Highway over the non-hybrid version.
AutoStop Doesn’t Always
There are a number of conditions where AutoStop does not activate. This is important to know since you only get the benefit of the hybrid drivetrain when AutoStop activates. The situation the driver has total control over is the HVAC setting. The Malibu Eco has two air conditioning settings: A/C Eco and A/C Comfort. In A/C Comfort, the engine will operate to run the air condition compressor to keep the cabin at the desired level.
With the A/C Comfort setting, the engine will almost never AutoStop. Or if it does, it quickly restarts. In A/C Eco mode, the engine shuts off (AutoStop), but the fans continue to circulate the cabin air. In A/C Eco mode, the engine goes into AutoStop every time the vehicle comes to a full stop.
Conditions outside the driver control may cause AutoStop to activate less frequently or for shorter periods of time, i.e., the engine will continue to run or may restart when the vehicle is stopped. First, when the engine, trans or high voltage battery is not at the required operating temperature. Second, when the outside temperature is below minus 4 deg F. Third, when the high voltage battery is at a low charge.
Fourth, when the rear window defog is activated. Fifth, when the AutoStop has timed out more than two minutes. Sixth, and most importantly, AutoStop only works with the gear selector in Drive (D). AutoStart does not activate when the car is in Park. Put another way, AutoStop is not an anti-idle device. The Malibu Eco will idle indefinitely in Park. AutoStop only reduces engine idle time in Drive.
The Malibu Eco has a five-year/100K-mile powertrain warranty. All of the eAssist components have a warranty of eight-year/100K miles.
The NextGen Malibu was upgraded from the Epsilon LWB platform to the Epsilon II platform, the same platform used by the Buick Regal. The wheelbase is 4.5 inches shorter than the outgoing 2011 Malibu, but the track (front and rear) is 2 inches wider, matching the Impala. Change in platform resulting in a stiffer body structure, better suspension design, and roomier interior. Overall, the new Malibu has 2.3 cubic feet more (97.7 cf to 100.0 cf) passenger space than the old Malibu…and you immediately feel it.
The overall width is 3 inches wider than the previous Malibu, and now equal to the Impala. The front and rear headroom is now comparable to the Impala, and so is the front and rear legroom. The front and rear shoulder room is more than 2 inches greater than the previous Malibu, and now very close to the Impala. The new Malibu has 2.7 inches more hip room, critical to police officers. Again, this is now comparable to the Impala.
As you evaluate the current selection of police-suitable sedans of any make, don’t overlook “foot” room. Patrol, detective, admin…we all wear real shoes. Some sedans are very tight where your feet are placed, i.e., the so-called foot box, the space from the inner wheel well to brake pedal to accelerator to center hump or console. The Malibu Eco has enough room for your feet. Other small full-size and large mid-size sedans do not.
The trunk is larger on the new-generation Malibu models (15.1 cf to 16.3 cf), but some of that is taken up by the Malibu Eco’s battery, reducing it back to 13.2 cf, but trunk space is seldom an issue on an admin sedan.
After hundreds of hours in GM’s wind tunnel, major reductions of drag were accomplished. In fact, the improved aerodynamics alone have been credited with a 2 mpg improvement to the EPA Highway numbers. This is an improvement from a 0.35 Cd to a 0.29 Cd. The restyled Malibu has a drag coefficient almost identical to the slippery Volt and sleek Corvette.
Like the Chevy Cruze and Buick LaCrosse, the Malibu Eco has active grille shutters in the lower front intake opening. Electric motors open and close these lower air shutters based on engine cooling demand (coolant temperature) and vehicle road speed. The shutters are opened at lower speeds, when traveling uphill, when towing, during stop-and-go traffic in hot weather, or any other condition when the engine needs more cooling air.
The shutters are closed at higher speeds when the engine cooling demands are less. When closed, the shutters redirect airflow around the front of the Malibu and down the sides. This makes less aero drag than allowing the air to enter the front of the car and exiting under it or through the wheel wells. On the topic of under the chassis, four under-body panels cover about half of the underside. This makes a cleaner airflow path under the vehicle.
The ride, on both urban streets and rural highways is comfortable, which is just what you would expect from a world-class midsize sedan. The Malibu Eco has tight and responsive steering. Handling is typical of a non-police package, retail sedan—mid-size or full-size. The body roll is dampened—the sedan is very capable in evasive maneuvers and emergency lane changes. Frankly, it felt like the Impala 9C1…almost, which is pretty good for any FWD retail sedan. The suspension is a good balance between firm (handling) and soft (ride comfort).
The new Malibu uses electric-assisted power steering. If you didn’t know it, you would never know it. The feel is very traditional, very conventional. Yet, if you really pay attention (Jackie Stewart’s single-element analysis way to test drive), you can feel an improvement. The on-center feel is better, as is the road-to-wheel feedback, as is the reduced-boost higher effort at higher speeds. But if you just get in and go, you will never know.
The Malibu Eco’s power is surprising. Acceleration is not a major issue in an admin sedan. Even still, the larger 2013 Malibu Eco is much faster than the smaller 2008-2010 Malibu Hybrid. The 2.6 second improvement in 0 to 60 mph time from 11.5 seconds to 8.9 seconds is huge. It accelerates to 60 mph exactly as fast as the Ford CVPI (8.9 seconds). Not that admin-detective vehicles are pushed to 100 mph very often, but the Malibu Eco gets there in 22 seconds, again, just as fast as the Ford CVPI.
Frankly, some of the vastly improved acceleration is due to the upgrade from a 4-speed trans to a 6-speed. The 6-speed does everything better. The lower gears are better matched for acceleration. The higher gears are better matched for acceleration. The higher gears are better matched for fuel economy.
The eAssist mild hybrid drivetrain, the aerodynamic improvements, and reduced rolling resistance tires result in a 25 mpg EPA City and 37 mpg EPA Highway, for a 29 mpg Combined. On pure highway driving, we did not get the EPA Highway estimate of 37 mpg. We got 33 mpg. However, during suburban calls-for-service, we beat the EPA City estimate of 25 mpg. We got 29 mpg. During our 1,100 miles with the 2008 Malibu Hybrid, we averaged 26.6 mpg. During our two weeks and 1,600 miles with the 2013 Malibu Eco, we averaged 30.9 mpg, beating the EPA Combined value.
The NextGen Malibu is as roomy as the Impala. The 2013 Malibu Eco with the NextGen BAS hybrid engine is much more fuel efficient (and much faster) than the original 2008 Malibu Hybrid. Bluntly put, the 2008 Malibu Hybrid was all green hype and definitely not worth the upcharge. And it was slow. And it was cramped.
On the other hand, the 2013 Malibu Eco more than delivers on both gas and mileage and performance. And it is roomy. Seriously consider the Malibu Eco for admin use, whether or not your department is under a green initiative. It is a heads-up, excellent sedan. No drawbacks. No excuses. It is a hybrid without the hybrid hype. It under-promises and over-delivers.