Hoovey689

iTrader: (16)

Quick Spin: 2012 Buick LaCrosse eAssist

It's hard to talk about all of the good things General Motors is doing these days without referencing the Chevrolet Volt – it is perhaps the most talked-about car on the scene, green or otherwise. In showing the world that highly efficient, practical cars aren't so far out of our reach, GM is preparing to launch a slew of fuel-sipping vehicles in the near term.

We've already spent time with the honest-to-goodness 42-mile-per-gallon Chevrolet Cruze Eco, but the next chapter of GM's efficiency story lies in Buick's eAssist mild hybrid system, coming to both its LaCrosse and Regal sedans later this year.

We recently had the chance to drive the 2012 Buick LaCrosse eAssist on the roads near GM's proving grounds in Milford, Michigan, and while some hybrid systems vastly change a car's overall driving experience, we walked away from our time in the Buick feeling as good as we ever have in a LaCrosse. The beauty of eAssist is that it functions in an almost entirely transparent manner, and that's a very, very good thing.

The LaCrosse is a sharp-looking sedan, and Buick made a point of not changing 98 percent of the car's exterior design in fitting it with the eAssist package. The only real change is the addition of model-specific 17-inch alloy wheels wrapped in Michelin Energy Saver A/S 245/50-series rubber. These tires were designed by the Bibendum Bunch specifically for GM, and while we're perfectly happy with the use of these energy-saving tires, we'd be thrilled if they were fitted to slightly larger wheels, if only for aesthetics. The LaCrosse's large dimensions and wheel wells designed to properly house 19-inchers at all four corners just make this eAssist-specific set look teeny-tiny.

There are no eAssist badges on the LaCrosse, either – an intentional omission that GM admits will have both positive and negative ramifications. While having a badge on the car is basically free advertising for one's green initiatives, GM didn't want to alter any other parts of the LaCrosse's design, however small. This is an interesting decision, especially from the company that was perfectly okay with fitting an obnoxious decal package to its Chevrolet Tahoe, GMC Yukon and Cadillac Escalade hybrid SUVs.


Buick engineers have spent a lot of time enhancing the LaCrosse's aerodynamics, and in doing so, they've managed to cut the sedan's coefficient of drag from 0.314 to 0.30. Active air shutters are used on the lower front air intakes – the same parts as the Cruze Eco, actually – and covers have been added to the underbody to keep air flowing smoothly beneath the car. You won't notice any of this during a walk-around of the eAssist LaCrosse, but get the car up on a lift, and you'll definitely be able to point out all of the changes.

The LaCrosse's comfortable, well-appointed cabin hasn't been altered much, either. There was no sacrifice in luxury or available features, and the only big changes to note are the slightly revised gauge cluster with a revised tachometer and eco driving gauge, and new functionality built into the large LCD screen that shows the eAssist's power flow while in motion.


As we previously discussed, Buick is eliminating trim levels for the 2012 LaCrosse, and optional amenities will be clumped together in large option packages. eAssist vehicles can be had with all the same kit as the V6 LaCrosse – save all-wheel drive – including leather, a panoramic sunroof, HID headlamps, navigation and so on.

The eAssist powerplant will serve as the base engine for the 2012 LaCrosse, with GM's 3.6-liter direct-injected V6 available as a no-cost option. In this case, the eAssist hardware is mated to The General's already efficient 2.4-liter Ecotec inline four-cylinder engine that produces a perfectly adequate 182 horsepower and 172 pound-feet of torque. The 115-volt lithium-ion battery and 15-kilowatt electric motor combine to offer as much as 15-hp worth of assist during initial acceleration, and eAssist uses other typical mild hybrid features like regenerative braking, fuel cut-off, torque smoothing and start-stop to maximize efficiency.


The end result? An EPA-estimated 25/37 mpg city/highway fuel economy rating. These aren't the lofty 40-plus-mpg numbers we're getting so used to hearing about, but in the 3,835-pound LaCrosse, it's hugely impressive. No other cars in the Buick's size category even come close.

Perhaps the best part about driving the LaCrosse eAssist is how unobtrusive the system is to the car's already serene driving experience. Sure, you notice the start/stop system at lights, but there's no engine shake upon startup, and because of all the sound-deadening put into the LaCrosse's interior, you barely hear it all working. The engine turns on as soon as the brake pedal is released, so there's no delay in power upon pressing the accelerator.

It's not quick, this LaCrosse, but it accelerates smoothly and it never feels overly sluggish, the six-speed automatic transmission firing off shifts smoothly in an effort to keep engine revs as low as possible. What's more, eAssist sends electric boost to the engine – almost like a turbocharger – to eliminate the need for downshifting during mid-range acceleration. When the transmission does kick down, however, we found that the noise isn't pretty, especially higher up in the rev range. Keep steady on the accelerator, however, and it's something you won't notice.


Adding eAssist doesn't really change anything else mechanically, but the special fuel-saving tires required slight readjustments to the steering and suspension system – a minor complaint. Even with its newly fitted electrically assisted steering, driving the LaCrosse is perfectly pleasant; steering response is good without feeling overboosted, and very much in-character for a big, loping sedan. The brakes have a linear, secure feel, whereas most regenerative systems are a bit touchy upon initial touch of the stop pedal. Suspension damping is perfectly tuned for a vehicle like the LaCrosse, offering a smooth, comfortable ride even over the broken pavement surrounding GM's test facility.

Buick tells us that the eAssist system is pretty much plug-and-play with GM's 2.4-liter engine, which is why we'll be seeing it on the smaller Regal later this year. Beyond that, there are plenty of options for further placement. Could we see an eAssist-equipped Verano? Maybe. What about a GMC Terrain, Chevrolet Equinox or next-gen Malibu? It's not such a far stretch.


Buick says that the 2012 LaCrosse will be priced from "around $30,000" when it hits dealerships this Fall – a price jump of over $3,000 based on the 2011 model's MSRP. And while that's quite a hike, Buick has added more features like a premium audio system as standard equipment in order to keep things competitive. It's still a decent price to pay when you consider that the LaCrosse offers solid value and eAssist represents a 25-percent gain in fuel economy.

Buyers will shortly be able to walk into a showroom and see two LaCrosse models at one price point – the eAssist focused on efficiency and the V6 geared toward a more commanding driving experience. It's a great proposition for new buyers, but with a mild hybrid system that's so streamlined and nicely integrated – not to mention one that carries a 37-mpg highway economy rating – we doubt Buick dealers will have any trouble making substantial sales strides with this new eAssist system.

Gallery:
http://www.autoblog.com/photos/2012-...-spin/#4019530

http://www.autoblog.com/2011/04/01/2...k-spin-review/

bad co

Maybe I missed it but, the e assist program is a hybrid variant. I always assumed that H cars get better street MPG's how does this system improve highway MPG?

Sulu

The eAssist, like GM's original Belt Alternator Starter (BAS), is a MILD hybrid system, unlike Toyota's Hybrid Synergy Drive, which is a FULL hybrid system. A mild hybrid system has a small electric motor/generator that gives the car only limited features:

1. The electric motor/generator assists the gas engine (as described, it acts like an electric turbocharger). That allows for a smaller gas engine, which is where the fuel economy savings comes from.

2. The electric motor/generator provides regenerative braking, recharging the battery.

3. The electric motor/generator provides an idle-stop feature, stopping the engine when idling at rest and instantly restarting it again when needed. This is also where some fuel economy savings comes from.

4. Unlike a full hybrid system, the mild hybrid system's electric motor/generator is not powerful enough to drive the car in electric vehicle (EV) mode. EV mode is what allows the full hybrid's city fuel economy to be better than its highway fuel economy. The HSD can accelerate from rest and drive the Prius (for instance) for short distances, at limited speeds; this is what gives the full hybrid system city fuel consumption that is lower than its highway fuel consumption.

The mild hybrid car's gasoline engine is always running when the car is running (just like a normal car); the electric motor merely provides an extra boost of power (similar in concept to a turbocharger) and allows for the fuel-saving idle-stop feature.

The eAssist, like the BAS, replaces the engine's alternator with a slightly more powerful motor/generator that can provide that electric turbocharger boost and restart the engine after it stops at idle. It is a very simple system.

spwolf

at $3k price surcharge, i would have liked them to report their mpg...

bitkahuna

iTrader: (20)

that distinction will be lost on 99% of the public with blizzards of advertising.

isn't that up to like 20mph? in the hybrids i've been in/driven it only runs in electric mode for a few yards unless it's a careful parking lot demo.

not knocking toyota/lexus system, it is superior, but i think the differences will be lost on the car buying public, unless economy figures are hugely different.

spwolf

difference is easily felt - this is basically a lot like Honda's IMA system and you can read pretty much anywhere how it is hard for it to use electricity only... on HSD you can be crusing at highway speed and it could switch you to eletric only.

This is why city rating is so poor compared to full hybrids (for instance 12 MPG compared to Fusion)

Ty419

I'd have thought that since GM's hybrid systems could have a significant impact on the company's long-term viability, they would have chosen a better name than eAssist. I'm guessing they either had a high school competition to name the system or their marketing team is super jealous of Apple's use of i-everything.

spwolf

might be them trying to tell us how their Volt is game changer and how hybrids are much inferior :-)

SLegacy99

37 MPG on the highway vs. 30 for the gas only model. You have my attention.

Sulu

The type of hybrid system -- mild or full -- will be lost on most buyers, but this really does not matter. What will be noticeable is the fact that a full hybrid vehicle will get much better (lower) city fuel consumption.

I don't know what the top speed is nor what the typical distance is before the gasoline engine kicks in for the Prius or the Camry Hybrid (or Lexus Hybrids). But the fact that a full hybrid car can actually accelerate away from stop completely in EV mode is what matters. It is the acceleration from stop that consumes a lot of fuel. The faster you can go and the farther you can go in EV mode will help the city fuel consumption figures. That is why the Ford Fusion Hybrid does better than the Camry Hybrid -- it can drive faster and longer in EV mode; I don't know if this is because of a more powerful and efficient electric motor or a greater capacity battery (or both).

Ideally, I think that if you can accelerate from rest right up to typical urban/suburban street cruising speeds -- anywhere from 30mph/50km/h to 45mph/70km/h -- completely in EV mode before switching on the gasoline engine for the steady-state cruise, you will get the lowest city fuel consumption possible. I believe that the Fusion Hybrid can do that.

The technology differences will be lost on the general car buying public but the bottom-line numbers -- city fuel economy and price premium over a comparable gasoline engine-only car -- will be what sways them. If the price premium for a mild hybrid (like GM's eAssist or Honda's IMA (Integrated Motor Assist)) is too high compared to the fuel savings, the mild hybrid car will not sell in large numbers. That may be one reason why Honda has never been a bigger player in the hybrid vehicle market.

Conceptually, it would have been so easy for Honda to turn its IMA from a mild hybrid system into a full hybrid system -- just add a clutch between the gasoline engine and the electric motor. That is what most other full hybrid systems -- Hyundai's, Porsche's/Audi's/VW's, and BMW's and MB's recent hybrid cars -- have done, allowing the gasoline engine to be disconnected from the electric motor so that the motor can spin without also turning the engine. This allows the electric motor to drive the car in EV mode without spinning the engine.

The "eAssist" (perhaps derived from "electric Assistance") name is similar to Honda's "Integrated Motor Assist" (IMA) name. These mild hybrid systems serve only in an ASSIST function: give a boost to the gasoline engine while accelerating (allowing the car to run with a smaller gasoline engine), and give the car an idle-stop feature (allowing the gas engine to automatically shut off while idling). This is a very simple concept. And, yes, the name may have been chosen to differentiate the mild hybrid from the Volt's Extended-Range Electric Vehicle (full hybrid) system.