GM Expands eAssist Mild Hybrid System to 2012 Buick Regal

By Nick Chambers

At the 2011 Chicago Auto Show, Buick announced that the 2012 Regal will be its second vehicle to sport the eAssist mild hybrid system—following in the footsteps of the 2012 Buick LaCrosse. With an EPA estimated 26 mpg city and 37 mpg highway, the 2012 Regal with eAssist will be 25 percent more fuel efficient than the conventional four-cylinder Regal.

GM’s mild hybrid system utilizes a relatively simple 15 kW motor/generator mated to a 2.4 liter Ecotec four-cylinder engine with a 6-speed transmission and connected to a 115 Volt, 65 pound lithium-ion battery which is recharged via regenerative braking. The battery is built by Hitachi and tuned for quick power input and output instead of high energy storage, as with a full hybrid or electric vehicle.

“We’re going after the low hanging fruit of hybridization,” said Steve Poulos, Buick’s Global Chief Engineer for Mild Hybrid and Battery Electric Powertrains on a call with media. “We go after the things we can do with a simpler, lower cost electrical system and try and apply those to a mainstream conventional vehicle.”

Poulos added that GM is trying to lead in the “light electrification” arena. “We’ve done a lot of work on the Chevy Volt to try and lead at the high end of things and see how far can we take a technology, but we’re also trying to lead in this more foundational approach,” he said.

The eAssist system uses the energy stored in its batteries via regenerative braking to accomplish three things, as explained by Poulos on the call:

  • “After we recapture energy from regenerative braking, the first trick we do is shut the engine off and turn it back on automatically every time you come to a stop. This is typically thought of as start-stop and it is one of the features that most hybrids have and we’re able to do that very smoothly with the motor/generator.”
  • “The second thing we do is we shut the fuel off completely every time we decelerate and the extra torque of the motor/generator means that when you decide to change your mind in the middle of that, you can very smoothly drive away. You will have the very quick response time you need without having to relight the engine. We can do that very aggressively—much more so than on a conventional powertrain.”
  • “The third thing we do is we provide electric boost during grade type maneuvers. When we get into a [uphill] situation we can apply extra boost from the electric motor and that will keep the transmission from downshifting. With this system we are able to go two final drive ratios more economical than the base vehicle.”

GM says that the end result of the eAssist technology is a car that has the same performance, drivability and comfort as other Buicks, but with higher fuel economy. Although slightly less robust, the system bears similarities to Honda’s mild hybrid technology.

Although eAssist isn’t as flashy as the technology used in the Chevy Volt, the potential for vast fuel savings is not being overlooked by G.M. It’s an effective and affordable technology that can be spread across entire lines of vehicles, much the way that Toyota, for example, wants to extend its hybrid technology to all its popular models. After all, it’s going to take some time for fully electric and plug-in hybrid technology to reach economies of scale, and begin to come down in price.

The 2012 Buick Regal with eAssist goes on sale in late 2011.


  • Bababooey

    I cannot believe that after being bailed out that GM is rebranding the same technology again and touting it as new. Where did all that money go?

  • Charles

    GM adds 20 HP of electric to a 3700 pound car and Honda adds 13 HP of electric to a 2700 pound car. So on a per pound basis Buick added more electric boost. Yet, people blast GM for their system, but most give Honda a pass.

    Please note that GM has learned a few lessons. First, the new system is not called a hybrid. Second, a system must be able to work on many models. Third, for most people to buy a system it must be a good value with very short payback. This new GM system may offer very good value.

    I hope GM does do a good full hybrid to compete with Toyota, Ford and Hyundai. Keep in mind only Toyota and Ford have sold significant numbers of full hybrid cars. There are about 30 major or simi-major car companies in the world. To hammer GM for being with the vast majority seems over critical.

    That said, GM really needs to step up its game in terms of quality and full hybrids. The Volt maybe a very nice car, but it is just a halo vehicle like the Leaf. We really need to see quality high MPG mainstream cars from all manufactures, and so far it looks like full hybrids are the best way to get there.

  • Anonymous

    @Charles:
    “GM adds 20 HP of electric to a 3700 pound car and Honda adds 13 HP of electric to a 2700 pound car. So on a per pound basis Buick added more electric boost.”
    So, how much ‘advantage’ does the GM eAssist really have?
    13×3,700/2,700=17.81 hp. Roughly 2.2 hp.
    Can one really feel the difference of 2.2 additional hp in a 3,700 lb car? Wow.

    “… for most people to buy a system it must be a good value with very short payback. This new GM system may offer very good value.”
    Have GM released the pricing of 2012 Regal eAssist yet? If not, don’t try to act like a prophet (or a psychic) and jump to conclusion.

    Let me say this, this is a good initial step for GM which, apparently, has been fallen behind in its fuel efficiency quest for sometime (unless you count Volt), but, to borrow a cliche, this is no ‘game-changer’, IMO.

  • Anonymous

    Furthermore, according to a previous article on this site about Buick LaCrosse with eAssist:
    “The new batteries bolster the engine with approximately 11 kW (15 horsepower) of electric power assist during heavy acceleration and 15 kW of regenerative braking power.”
    Does it also apply to eAssist of Buick Regal? I won’t be surprised.

    Beware of all those hidden behind marketing material.

  • Anonymous

    Hi, Anon. Just found this from a GM press release of 2012 Regal eAssist:
    “Regenerative braking, which provides up to 15 kW of electricity to charge the battery
    Providing up to 11 kW (15 hp) of electric power assistance during acceleration.”

    Oops. Your suspicion is confirmed. Thanks for your insight.
    Yeah, let the truth be told: ‘the emperor is not wearing any clothes’!

    So actually, the eAssist in Buick is only capable to provide 11 kw of power assist during acceleration, at est. (per Charles above) 3,700 lb. That is roughly (since GM has not released its weight, yet – but looks reasonable as the base CXL is already at 3,600 lb. – may be slightly above if options are added) 336.4 lb. per kw. For a Honda Insight, it is about 270 lb. per kw.

    So the myth that “on a per pound basis Buick added more electric boost” is just, fiction. On the contrary, it seems it’s 25% worse when measured in lb. per kw.

    Currently, a base CXL costs $26.2k. CXL Turbo starts from $28.7k.
    I won’t be surprised if the price of eAssist model is priced close to CXL Turbo.
    For comparison, a Camry hybrid starts from $26.7k.
    I estimate Regal eAssist EPA combined mpg about 30.95 mpg. (Toyota Camry 32.8 mpg) Is it still good value?

  • pat

    After its peak, GM only able to produce good news instead of deliver good products. That is why company like Toyota took GM’s #1 spot in the industry! I think Toyota will recover from its’ recalls disaster quicker than GM regain its industry leader status!

  • Charles

    This article states a “15 kW motor/generator” which works out to about 20 HP. I used the weight of the non-hybrid Honda Civic and after looking at other Buick Regal articles took an educated guess at the weight of the I4 version of the Regal. Now you know were I got my information.

    As for my point, even if the GM system is only 11 HP, GM gets hammered for bad mild hybrids and Honda gets a pass on a system that provides about the same amount of savings in fuel per year. At 15,000 miles per year the Honda Civic Hybrid saves about 151 gallons of fuel compared to the ICE version. The eAssist Regal saves about 141 gallons a year. For comparison the Ford Fusion Hybrid saves around 215 gallons.

    The question is how much eAssist will cost. As the article states it is an affordable system. GM is obviously trying to offer an inexpensive system to boost its MPGs. If the cost is around $1,200 I think it will be a success. At $2,400, forget it.

    As for being a prophet or a psychic. I have to make decisions all the time with incomplete data. If you need complete data to make a decision, I feel sorry for you.

    To state again, I think both Honda and GM need to build good full hybrid systems to compete with Toyota, Ford and Hyundai. If GM and Honda do not step up their hybrid game, Toyota, Ford and Hyundai will bury them. As for the hybrid pretenders, they really have a long way to go, with the exception of VW. VW has the clean Diesel market to themselves, which gives them some breathing room.

  • Max Reid

    Something is better than nothing. Next they should apply this system in Chevy Malibu as well, as its the biggest selling of GM’s sedan.

    BTW, Lucerne the big gas guzzler available in V6 & V8 versions with just the 4 speed tranny is going to be phased out by MY-2011.

  • Nelson Lu

    Buick’s mild hybrid system is likely to save ~25% fuel compared to the conventional version in the Regal.

    Honda’s mild hybrid system saves ~29% fuel compared to the conventional version in the Civic (41 MPG compared to 29 MPG).

    Somehow, though, the GM system is attacked as a failure and Honda’s hailed as a triumph. Somehow, I don’t think a 4% improvement is enough for that kind of a conclusion. As has been noted, it all depends on the cost that the eAssist Regal will add.

  • Anonymous

    Well, the electric motor of Civic hybrid is rated at 15kw(or ~20 hp). A 2011 model would weigh 2,877 lb. That comes to about 191.8 lb. per kw.

    To recap, Honda Insight is about 270 lb. per kw; Buick Regal eAssist in CXL, without additional option, is about 336.4 lb. per kw.

    Contrary to what a poster said above, Buick Regal eAssist is over 75% worse than Honda Civic hybrid when measured in lb. per kw.

    Charles said: “At 15,000 miles per year the Honda Civic Hybrid saves about 151 gallons of fuel compared to the ICE version. The eAssist Regal saves about 141 gallons a year.”

    IMO, this kind of logic is apparently flawed.
    It all depends on which model one uses as base for comparison. The Regal 182 hp 2.4L engine that is rated at 19/30 mpg is not particularly fuel efficient. It costs $2,029 for annual fuel to run 15,000 miles, according to EPA.
    A 2011 Toyota Camry 169 hp 2.5L is rated at 22/32 mpg and costs about $1,796 for annual fuel.
    A 2011 Honda Accord with 190 hp 2.4L is rated 23/34 mpg and costs only $1,726 for annual fuel.
    So comparing the Regal eAssist with a more fuel efficient vehicle like Camry or Accord would significantly reduce the amount of savings one could achieve and lengthens to time period required to recover the eAssist ‘premium’ GM charges.

    If one wants to look for a fuel-efficient mid-size four door sedan and pay as little as possible, it baffles me if they would not consider a Camry 4 cylinder or an Accord 4 cylinder.

  • Anonymous

    Hey Anon,

    Comparing the Buick Regal to the Toyota Camry is a false comparison. I know people on this site have practically anointed Toyota as the greatest thing since sliced bread but can we atleast try to be fair. The Buick is a luxury brand, the equivalent would be lexus not Toyota. To be fair GM does not have a hybrid that competes with the Toyota Camry (a Malibu or Impala hybrid).

    Comparing the Regal to Lexus I would say that it matches with the LS hybrid (203 inch length) which gets 20 mpg combined. If you want to compare the Regal to the HS hybrid however (185 inch length vs the regal 191 inches) then the HS gets 35 mpg combined. But if you are talking value the regal is in the 26 to 28 thousand range while both lexus vehicles are in excess of 30 thousand dollars. So to get a comparable class lexus will cost you $5000 and 5 mpg more fuel economy or $11000 with 12 mpg less fuel economy.

    The regal is not a game changer for the entire industry but it is a new way of business for GM. Lets look at this change in that light and stop making false comparisons just so we can know GM. This system is simple enough that for only a slight increase in cost it could be installed along nearly an entire line.

  • Anonymous

    Nelson Lu said: “Buick’s mild hybrid system is likely to save ~25% fuel compared to the conventional version in the Regal.

    Honda’s mild hybrid system saves ~29% fuel compared to the conventional version in the Civic (41 MPG compared to 29 MPG).”

    Mind you, the Civic hybrid you’re talking about was debuted in 2005. It’s almost 6 years old, for God sake. As posted above, the Regal 2.5L engine is not particularly fuel efficient from the beginning. Therefore, there’s more head room (or low hanging fruit, in GM engineer speak) available to improvement for GM. And yet the ‘new’ eAssist from GM, touting with all the latest technology available, achieves 4 percentage point ‘less’ fuel improvement! (Or 14% less improvement: 1-25/29.)
    What a ‘great’ achievement, some posters here proclaimed. And one tried to justify its ‘advancement’ by using ‘false’ data.

    And some posters want to pretend it’s competitive and try to defend it by comparing it with a vehicle to be replaced soon. Sigh.

    FYI, a new generation Civic hybrid with Li battery will be released in a few weeks time.

  • Anonymous

    Anon: “Comparing the Regal to Lexus I would say that it matches with the LS hybrid (203 inch length) which gets 20 mpg combined.”

    Are you joking? If you want to be treated seriously, may be you need to think before you post.

  • Anonymous

    Anon: “The Buick is a luxury brand, the equivalent would be lexus[sic] not Toyota.”

    What makes Buick a ‘luxury’ brand? Just because GM says so? The Regal is priced closely to a Camry with options.

    I can still remember Lutz has touted that Cobalt was a ‘premium’ product from GM and would be a ‘game-changer’, in today’s word. Few buyers would agree. Now, the Cruze is the new ‘premium’ small car from GM, if you take their words at face value.

  • Anonymous

    Actually its not my opinion that Buick is considered a soft luxury car in the same group with Acura, Lexus, Lincoln and Volvo. That is the opinion of Car and Driver magazine:

    “Buick has now set its stall as a rival to the soft-luxury automakers such as Acura, Lexus, Lincoln, and Volvo, leaving the more hard-core field of German brands to Cadillac. Mind you, brand loyalists might still have a problem getting their heads around a Buick that can actually compete with an Acura.”

    But don’t worry you can keep your pre-existing biases and ignore anything that doesn’t fit. I don’t even know why GM still makes cars, because according to most of the people here nothing they make should even sell.

  • Charles

    OK, I did mess up the HP on the Civic. I thought it was 13, not the 20 that it is. Sorry about that.

    My overall point is still valid. The GM eAssist system offers about the same fuel savings as Honda’s IMA in a Civic. The Honda system is praised and the GM system vilified. That shows that some people do not look at the data. For me, I think both GM and Honda need to improve their hybrid offerings. Maybe the new Civic Hybrid will be that improvement. Honda’s track record with hybrids does not inspire confidence.

    For my money, I will buy a proven full hybrid from Toyota or Ford.

  • Anonymous

    Oh, did you missed the first para. of the C/D article you quoted?

    Oops. It doesn’t look good.

    “If General Motors hadn’t imploded, the Buick Regal wouldn’t have been a Buick; it would have been a Saturn. The Regal is essentially a European-market Opel Insignia—a mid-size sedan that competes with the Ford Mondeo, Honda Accord, and Volkswagen Passat over there—rebadged and rebranded for the U.S. and China.”

    Did C/D just let slip the ‘secret live’ of Buick Regal before it ‘officially’ became Buick?
    May be some Americans would feel that a car in Europe developed to compete with Ford, Honda, and VW and to sell as a Saturn is suddenly ‘good’ enough to fight other ‘luxury’ brands when it is rebadged Buick.
    Sorry, not me. I don’t buy this marketing talk.

    How about Buick’s other new product for 2012 MY – the Verano?

    “[I]t was Lauckner[GM VP of Global Product]‘s assessment of the Verano’s potential competition that sounded off-key to my ears. I was expecting to hear names like Lexus and Audi or perhaps the BMW 1 series, and instead I heard names like Corolla, Camry, Accord and Civic. [...]

    During that press conference, Chevrolet’s sales growth in the BRIC countries was highlighted. If I was the type that connected dots, I’d say that GM is repositioning Chevy as their bargain basement “world” brand, allowing Buick to become their mass market brand for middle America, while Chevrolet does battle not with the Camrys and Civics but with the Sonatas and Optimas. [...]

    Others attending the media preview reported similar comments from lower level GM personnel. Even the attractive “product specialists” hired to work the show for GM more frequently compared the Verano to Toyotas and Hondas than to BMWs, Audis and Lexuses.”

    From LeftLaneNews: A DISAPPOINTING CHAT WITH GM ABOUT THE BUICK VERANO

    So, GM plans to attack Toyota and Honda with Verano? It puzzles me that Buick could be considered a ‘luxury’ brand by some.

  • Anonymous

    Charles said: ” My overall point is still valid. The GM eAssist system offers about the same fuel savings as Honda’s IMA in a Civic. The Honda system is praised and the GM system vilified. “

    Charles, you have an axe to grind against Honda?
    I think Honda’s system is praised because it came to the market more than 6 years ahead (the 2012 Regal eAssist is available near the end of the year) of GM’s Regal eAssist while still saves more fuel (about 14% according to a post above). It seems GM wants to be competitive, but still lags behind despite it tried its best.
    Please, at least, try to show you look at it objectively.

    I think a poster has shown that GM’s claim that eAssist can save up to 25% in fuel economy is partly because the bar set by Buick Regal 2.4L is pretty low, it is more powerful than a Camry 2.5L but consumes about 13% more fuel (according to EPA est.); but it consumes more (about 18%) fuel but still be less powerful than a Honda Accord with 2.4L engine.

  • Anonymous

    Breaking news: “U.S. believes Saudi Arabia is running out of oil”?

  • Charles

    Objectivity?

    Quote 1: “For me, I think both GM and Honda need to improve their hybrid offerings.”

    Quote 2: “To state again, I think both Honda and GM need to build good full hybrid systems to compete with Toyota, Ford and Hyundai. If GM and Honda do not step up their hybrid game, Toyota, Ford and Hyundai will bury them.”

    Quote 3: “That said, GM really needs to step up its game in terms of quality and full hybrids. The Volt maybe a very nice car, but it is just a halo vehicle like the Leaf.”

    Statement 1: The two systems are close to equal.
    Statement 2: One is praised, the other vilified.

    Do you disagree with either statement? If not how am I being unfair to Honda? I am just saying that it is really odd two systems so close in ability are perceived so differently. It is true that I will not consider a Honda IMA hybrid as my next car. I also will not consider an eAssist car. The Honda Insight and CR-Z are both panned by CR, which is enough for me to toss them from consideration. I just do not like the Regal and I do not trust GM.

  • Nelson Lu

    Anonymous, Honda might have made it to the (North American) market first, but during that time span, it made very, very little improvement to its system. During that timespan, Toyota, Ford, GM, and Nissan all entered the marketplace, and each has either made fairly large improvements in its systems (Toyota/Ford) or have introduced potential game-changer cars (GM/Nissan, although Nissan’s manufacturing capabilities may be suspect). Honda has done virtually nothing. And soon, Hyundai is going to be in the marketplace as well. Honda’s being caught flat-footed.

  • Collin Burnell

    Wow! You guys (and gals) are really missing an important point…

    Electric motors are not about horsepower…

    Electric motors provide Torque! This one provides “nearly 80 lb-ft torque of assist during acceleration” (CrunchGear).

    Throw an additional 75+ lbs of torque in there and now you have something!

  • Anonymous

    Charles said: “The question is how much eAssist will cost. As the article states it is an affordable system. GM is obviously trying to offer an inexpensive system to boost its MPGs. If the cost is around $1,200 I think it will be a success. At $2,400, forget it.”

    Currently, a Buick LaCrosse CX starts from about 27k; CXL about 29.6k; CXL with V6 engine starts from about 31k.
    GM has announced the Buick LaCrosse with eAssist will be priced at ‘about’ 30k.

    A Buick Regal starts from about 26.25k; a turbo model from about 28.75k.
    Is a Buick Regal with eAssist going to start from 27.45k(26.25 + 1.2)?
    I won’t hold my breath for it.

  • Anonymous

    @Colin: The additional 75+ lb. ft. of torque provided by the electric motor in GM’s eAssiist sounds impressive, until you realize it max out at 1,000 rpm.

    When the rev reaches over 2,000 rpm, it is calculated that the amount of torque from the motor available will drop to ~40 lb. ft. or lower. Unlike CVT or planetary gear, the 6 speed slush box adopted by GM could not optimize the great torque offered at low rpm.

    Lastly, don’t forget we are talking about a vehicle likely to weigh from 3,800 lb.

  • Music Man

    …so the lb. ft. of torque never get used?

  • Anonymous

    “…so the lb. ft. of torque never get used? “

    Well, to be fair to GM, the eAssist does offer its benefits, e.g. to accelerate from dead stop or very low rpm, like below 2,000 rpm.
    (My concerns are more about the weight of the car relative to the power available from the electric motor and adoption of slush box by GM. An auto transmission has no way to maintain linear engine rpm while accelerating.)
    The increase in fuel economy, as measured in EPA cycle, has to come from somewhere.
    But once the rpm of the engine rises pass low rev of, say, 2,000 rpm, the benefits may dramatically decrease.

    It looks like GM’s eAssist would provide largest benefit if the driver uses a very light foot for acceleration, probably similar to those during EPA test cycles.

    Caveat emptor.

  • Nelson Lu

    Anonymous writes:

    “Currently, a Buick LaCrosse CX starts from about 27k; CXL about 29.6k; CXL with V6 engine starts from about 31k.
    GM has announced the Buick LaCrosse with eAssist will be priced at ‘about’ 30k.”

    Depending on the actual pricing structure, this can be misleading. Some people have misleadingly claimed that Ford adds an $8k premium for the Fusion Hybrid by comparing the price of the base Fusion S with the base Fusion Hybrid. That is completely misleading because the base Fusion Hybrid’s equipment level is the same as the base Fusion SEL. So, part of the question is going to be: how’s the LaCrosse eAssist going to be equipped?

  • Capt. Concernicus

    This “new” technology from GM is really “reheated” tech from the last time GM was touting mild hybrids. When will GM bring out full blown non-plug in hybrids?

  • Anonymous

    whoopie doo… another snail like progress from gm.

    gm needs to “put the peddle to the floor” if they wish to compete with toyota or avoid the next bailout.

  • John Rendo

    I don’t know why you guys are trying to complicate things (lb per kw) and how much assist is actually provided during acceleration. Truth be told the vehicle is getting 26mp in the city and 37 on the highway. Which is 31.1 avg if you want to get technical and I”m sure the good folks at GM will find a way to figure out another 2 to 3 mpg before the vehicle hits the streets. This is what I really would like to know. How on earth are you comparing the Camry Hybrid to a Regal with E-Assist? Have you driven the Regal….. Probably not! You are probably one of these guys that swears that Japanese automobiles are far superior than any other, and that’s how you justify buying one! When you are going to respond to an article in a educated manor, next time, try to leave your personal opinions out of the conversation!

  • Jay

    I know this is an old article and an old comment, but it’s not “an extra 2.2HP in a 4,000-pound car.” It’s an extra 7HP for another 1,000 pounds, and as the commenter mentioned, it’s the power-to-weight ratio that is vastly improved over the Honda. “Horsepower” can be a deceptive rating compared to the horsepower in an internal combustion engine, as an electric motor makes instantaneous torque from “idle”….much more torque than horsepower, in most cases. It’s torque that gets a vehicle moving.

  • Ron Turkett

    I have a 2012 Buick LaCrosse and the fuel economy is much lower than the window sticker and is lower than my Camry V6. If you compare the Buick 4 Cyl with the Camry 4 cyl there is a huge difference. GM models have actual mileage less than the window sticker and Toyota models can beat the window sticker numbers. Also, the DIC in Toyotas are accurate and G.M.s DICs from my experience with many overstate the true mileage. The mileage results are hard to explain since the window sticker numbers come from the same EPA testing. My experience with Camry 4 Cyl is based on highway speeds of 20 to 80 MPH. The Buick drops significantly at 70MPH.

    Field service engineers had my car for two days and pronounced everything checked out OK. I was hoping my car had a problem so other Buicks would be ok.