Toys4RJill

https://www.caranddriver.com/reviews...id-test-review


A passive approach to green technology.

Electrification is perhaps the automotive buzzword today, but General Motors has been offering various hybrids for more than a decade. The Buick division launched its first such vehicle back in 2012: the LaCrosse eAssist, a hybrid version of its large sedan that continued through the 2016 model year. When the third-generation LaCrosse was released for 2017, the technology was absent from the order sheet, but Buick reupped on the hybrid for 2018. The four-cylinder eAssist now is the entry-level powerplant. Unlike many eco-themed vehicles that telegraph their green-leaning powertrains, however, the LaCrosse keeps its electrification on the down low.

HIGHS
Expansive rear seat, excellent fuel economy, seamless hybrid powertrain.

LOWS
Disconnected driving experience, uninteresting interior, confined front-seat space.

Take a walk around the LaCrosse and there are only four badges in sight: the Buick tri-shield logo on the grille and the center of the trunklid, Buick spelled out on the left side of the trunklid, and LaCrosse on the right side. There’s nothing else on the rear or on the body sides to indicate that this car has hybrid technology under the skin. Not even a funky color choice like bright green, chrome yellow, or electric blue. Our test car was white with chrome wheels—classy but conventional.VIEW 86 PHOTOSThe same aesthetic carries through to the interior. There’s no weird dash arrangement for the sake of being different, no strangely patterned or colored trim, no oddball shifter. The one thing that hints something environmentally friendly is going on is a tiny digital leaf on the right side of the gauge cluster; it acts as the needle on a meter that ranges between ACCEL and BRAKE. Seeing such labels might seem silly considering how elementary those tasks are in any car, but it denotes the two areas where the eAssist system comes into play.

Spawn of Saturn

This branch of GM’s family of green machines can be traced back to Saturn—remember that brand?—which launched the Vue Green Line SUV for the 2007 model year. The Green Line introduced the belt-alternator-starter (BAS) system. The BAS technology has been applied to many GM vehicles since then, incrementally improving through the years and eventually being marketed as eAssist. It uses automatic stop/start and a small amount of electric assist and regenerative braking to boost fuel economy.

In the LaCrosse, the hybrid system consists of a 2.5-liter inline-four gasoline engine, an electric motor/generator, and a 24-cell 0.5-kWh lithium-ion battery pack. The electric motor, which GM calls the Motor Generator Unit (MGU), takes the place of a conventional alternator and is belt driven or belt driving, depending on its mode. Regenerative braking collects energy, the MGU converts it to electricity, and it’s stored in the air-cooled battery pack.VIEW 86 PHOTOSWhen the LaCrosse comes to a stop, the gas engine shuts off and the battery powers the rest of the car’s functions, such as the infotainment and HVAC systems. It’s then used to restart the engine when the brake is released and can also provide additional torque when the driver presses the accelerator. Buick claims it provides 9 percent more torque than the previous LaCrosse eAssist, plus the system’s overall size is smaller and has been packaged more efficiently.

Even so, the battery impinges on trunk space. Although the rear seats fold down, the rectangular bump in the trunk floor stretches across the pass-through opening to the car’s cabin. The loss of cargo space is only one cubic foot (14 versus 15), but the disruption of the load floor makes it more of a detriment than those numbers suggest. Still, it’s less intrusive than the previous LaCrosse eAssist’s battery pack.

How Light Is Light Electrification?

The 2018 LaCrosse eAssist is EPA-rated at 25 mpg city, 35 highway, and 29 combined, which is only slightly improved from the 2016 model’s 24/35/28 ratings. We averaged 27 mpg overall and managed an impressive 38 mpg on our 75-mph highway fuel-economy test. The higher-trim LaCrosse models come with a V-6 engine; when we tested a front-wheel-drive V-6 version—152 pounds heavier than this front-drive eAssist—it managed only 31 mpg on its highway run and returned 24 mpg overall.VIEW 86 PHOTOSThe eAssist, which uses a six-speed automatic transmission, took 7.8 seconds to accelerate from zero to 60 mph, which is neither glacial nor zesty. Paired with an eight-speed automatic, the V-6 in the 2017 LaCrosse (2018 V-6 LaCrosses have a nine-speed automatic) showed impressive thrust and propelled the front-wheel-drive model to 60 in 5.9 seconds; an AWD model moved off the line slightly quicker, at 5.8.

So the jump in fuel economy comes at a significant cost in acceleration. But at least the hybrid system is imperceptible in operation. The only indication that the powertrain is trying to save gas is the stop/start function, and that feature is now standard on plenty of nonhybrid vehicles.

They DO Exist

For the rare people who fondly reminisce about the times when couches on wheels roamed the streets, the LaCrosse is a nostalgic blast from the past. At nearly 200 inches long, the LaCrosse is huge, and it drives like it. The steering is slow with zero indication of what’s happening beneath the car, and around turns it feels as if the body is perched on top of a Bosu ball. It’s not floaty, however, but rather purposeful and controlled.VIEW 86 PHOTOSThe disconnect between the road and the driving experience does make for an extremely serene cabin. The powertrain is smooth and quiet, road noise is effectively blocked, and bumps are easily dispatched without disturbing the ride.

The interior does not feel as premium as it should considering our test car’s near-$45,000 price. The dashboard is clean and well organized, but the layout drew some complaints, as the massive center console eats space and creates a confined feeling for the driver and front passenger. The place to be in this Buick is the loungelike back seat. Headroom and legroom in the rear are copious, the seats are plush, and the ride is supple. We’d be ecstatic if our Lyft driver pulled up in one of these.

And with its impressive gas mileage, the LaCrosse eAssist indeed would be a solid choice for a part-time taxi. For those who don’t like the sacrifices that often come with a hybrid, this Buick provides extra mileage in a comfortable and understated package.

Toys4RJill

Why not just go all out and do a full hybrid like the Avalon or ESh?

mmarshall

On the other hand, why invest even more money and development in a car that might not survive another year or two? Its competitor MKZ over at Lincoln, its own brother Chevy Impala, and its upscale brother Cadillac CT6 may also be biting the dust with it.

There's a reason why I ordered my car when I did.

That is EXACTLY why I like this car....and its competitors like the MKZ, Impala, ES350, Cadenza, and G80.

Toys4RJill

Nobody would of known when they released this new LaCrosse that it would potentially be cancelled later. Highly doubtful it will get the axe.

mmarshall

Remember, Jill, this is GM....the corporation notorious for introducing products and then axing them in a few years. I generally like Mary Barra, but that seems to be one of the (few) things at GM that has NOT changed with her at the helm. Hey, you saw what they did to the successful Verano, didn't you?....even in spite of its reliability, stout construction, and good owner-satisfaction rate. Probably the only reason they have even kept the Corvette in production is that, with the demise of the Viper, it is America's only mass-produced two-seat sports car.

Hoovey689

iTrader: (16)

1. Possibly copyrights by Toyota. Ford's system is very similar to HSD and LHD, but a few differences.
2. More expensive to make a full hybrid than sandwich an electric motor between the engine and transmission. GM has been doing these eAssist powertrains for a decade now it seems. Remember the Two-Mode Hybrid Sierra and Silverado
3. Why not make it a PHEV instead. Borrow from Bolt/Volt/ELR.

LexBob2

I wonder how many eAssists are sold? I seems like it must be a very small number. In December GM sold 1,385 (-51%) Lacrosse in the U.S. and for the year <1,700 per month (-27%). It seems like eAssist would be a very small percentage of total sales. Anyone know if they are available in China?.

mmarshall

I've yet to see a new Lacrosse Hybrid at the dealership I bought my Lacrosse from....and it is a BIG place. Even though it's actually the base model of the 2018, the Hybrid seems to be a special-order car, with very few takers.

Toys4RJill

mmarshall

The Chevy Volt is every bit as advanced (if not more so) than the Toyota Prius Prime. But the Volt's days may be numbered, since it is built in the same plant (Detroit/Hamtramck) as the big GM sedans that may be discontinued to convert the plant to trucks/SUVs.

Hoovey689

iTrader: (16)

In regards to a GM hybrid likened to a Toyota one, none that I can think of. eAssist, PHEV, and BEV are the only electrified model types GM has in their portfolio that I'm aware of. Someone please chime in if you can think of one, otherwise I don't believe so.

mmarshall

You don't agree with the Volt/Prius-Prime comparison?

Hoovey689

iTrader: (16)

I do for those two models. But since those are specifically PHEV, and Jill's original question was asking about a GM equivalent to the Avalon Hybrid and ESh, then the answer is no GM doesn't.

There are Parallel Hybrids like the Saturn VUE, Aura Greenline, GM Two-Mode trucks, and the older Honda Insight, Civic, and Accord hybrids which rely on more regnerative braking, auto stop/start, and ICE acting a a generator for supplemental recharging.

Then there are Series Hybrids which are common in diesel-electric locomotives, and ships. In effect the mechanical transmission between the ICE and the wheels is removed and replaced by an electric generator and traction motor. This allows a vehicle with an engine/generator that only operates when needed, such as when the battery is depleted, or to charge the batteries.

Electric Traction Motors are more efficient than ICEs, with high power to weight ratios providing torque over a wide speed range, whereas ICEs are most efficient when turning at a constant speed. Some automotive series hybrid models include the range extender variant of the BMW i3, and the Fisker Karma. The Chevy Volt is almost a series hybrid but includes a mechanical link form the engine to the wheels above 70mph. Series-hybrids incorporate:

• Electric traction only – using only electric motors to turn the wheels.
• ICE – turns only a generator.
• Generator – turned by the ICE to generate electricity and start the engine.
• Battery – energy buffer.
• Regenerative braking – The drive motor becomes a generator and recovers energy by converting kinetic to electrical energy, also slowing the vehicle and preventing thermal losses.
• May be plugged into the grid to recharge the battery.
• Supercapacitors can assist the battery and recover most energy from braking.
• Can have In-Wheel motors

Lastly there are Power-Split or Series-Parallel Hybrids that incorporate power-split devices allowing for power from the ICE to the wheels that can be either mechanical or electrical. The main principle is to decouple the power supplied by the primary source from the power demanded by the driver. Toyota/Lexus used a fixed gear second planetary gearset on the RX400h and Highlander Hybrid. This allows for a motor with less torque but higher power density. Ravigneaux type planetary gearset and two clutches are used in the GS450h, which allows for either higher toque or higher speed while sustaining better transmission efficiency.

Degrees of Hybridization

spwolf

they dont have the tech and it would be likely too expensive to buy it from the supplier. This is likely worst from both worlds.

Sulu

The Belt-Alternator-Starter (BAS) Hybrid system is arguably the easiest (and therefore cheapest) method to electrify the conventional ICE powertrain.

It just replaces the alternator (generator) with a more powerful motor-generator in the same location, on the same serpentine belt. The motor-generator replaces the function of the alternator, acting as a generator and also allowing for regenerative braking; the engine or the transmission turns the generator (alternator), via the serpentine belt, to generate electricity to recharge the battery. It also acts as a motor to restart the engine after an automatic idle stop; after an automatic idle stop, the motor turns over the engine, via the same serpentine belt.

Other than a (small, low-power) hybrid battery, there are no other changes necessary. No changes are necessary to the transmission; it remains the same. There is no electric motor to sandwich between the engine and the transmission. This is what makes the BAS Hybrid system no simple and so inexpensive.

The BAS Hybrid is used in the Buick LaCrosse (labelled as eAssist) and in GM's Silverado / Sierra pickup trucks.

This is not, however, the only hybrid system offered by GM in its history. The BAS Hybrid is the second.

The first was the complex Dual Mode Hybrid system developed by Allison Transmissions (for buses) when Allison was still owned by GM. It embedded 2 electric motors inside a 4-speed automatic transmission. GM later partnered with BMW and DaimlerChrysler to further develop it for cars and light trucks. There were the Chrysler Aspen / Dodge Durango hybrids and the GM light truck hybrids, but other than those, I do not remember any other models using it.

Then there is the Voltec hybrid system used in the plug-in hybrid electric vehicle (PHEV) Chevy Volt. That transmission is, in fact (despite what GM claims it is), a series-parallel power-split device (PSD), although somewhat different in design from Toyota's Hybrid Synergy Drive PSD (and Ford's hybrid system).

The same Voltec transmission (at least the same design) is used in the Volt PHEV / extended-range electric vehicle (EREV), the Chevrolet Malibu Hybrid and the Cadillac CT6 Hybrid.

So, Toyota, Ford and GM have similar series-parallel hybrid systems.

I can understand that an automaker would want to develop and maintain 2 different hybrid systems -- a simpler and cheaper one for small, inexpensive cars, and a more complex series-parallel system for larger full hybrids and plug-in hybrids. There is talk that Toyota may develop a simpler, cheaper hybrid system for its smaller cars. But I do not understand why GM would use the more complex and more expensive Voltec system on the mass-market Malibu yet use the simpler and cheaper BAS on the near-luxury Buick LaCrosse. And would it not be more cost efficient to maintain only 1 hybrid system (either the BAS or the Voltec but not both) on a car platform (the Malibu and LaCrosse share a platform).