Showing posts with label bmw hybrid. Show all posts
Showing posts with label bmw hybrid. Show all posts

Thursday, May 27, 2010

2010 BMW ActiveHybrid 7 - First Drive Review

BMW seems to be on a mission lately to offer something for everyone, no matter how nonsensical a certain consumer’s particular set of needs and wants may be. Case in point: the brilliant X6 and its mutant half-sister, the 5-series Gran Turismo. The latest in Bavaria’s barrage of the bizarre, the ActiveHybrid 7—a full-size “luxury performance” hybrid—seems to actually make sense relative to those two. It doesn’t hurt the argument for its existence that a competitor from Lexus—the LS600hL—has been on the road for two years now.

What makes the ActiveHybrid 7 strange is BMW’s boast that it is the quickest hybrid sedan on the market. If speed is the objective, we’re not sure why a hybrid is the answer. Likewise, if fuel economy is the end goal, tuning the twin-turbo V-8 gas engine for an additional 40 hp and 30 lb-ft of torque seems silly. However, if a 7-series customer believes he needs a car more powerful than the 750i but doesn’t want to step up to the 12-cylinder 760Li—which we think he should—and also wants 15 percent or so better fuel economy, BMW has just the model.

BMW’s engineers claim they set out to increase fuel economy, and the performance gains are a secondary benefit they hadn’t intended, but that sounds like PR script to us. No dimbulbs, they probably had a hunch that adding a bunch of extra power and torque would make the car quicker. The official claim is a half-second quicker to 60 mph over the nonhybrid 750i, or 4.7 seconds—which would beat our tested time for the LS600hL by 0.7 second. A brief blast up the autobahn during our test drive confirms that the hybrid 7 rockets to its 150-mph governor without any of the lethargy commonly associated with hybrids. Later on, driving more like downtrodden suburban Americans, we saw an indicated 20 mpg.

So, It’s Fast. How Hybrid-y Is It?

Okay, so you really care about the hybrid bits? It’s a mild hybrid, meaning no gliding about on electric power and smugness alone. You want motion, you’re going to have to choke the planet with the internal-combustion engine. There’s an electric motor sandwiched between the gas engine and the torque converter in the eight-speed automatic transmission. It contributes an additional 20 hp and 155 lb-ft—for a combined output of 455 hp and 515 lb-ft—and allows the engine to sit quiet at stops, as it powers the accessories. Although it isn’t a completely seamless stop and start, the transition doesn’t call attention to itself.

Our larger complaint is that, although the engine fires up as soon as you lift your foot from the brake, if you snooze at a light or are inching through a left-turn lane waiting for a break in traffic, a quick leap from brake to gas beats the reignition process and results in a herky jerk forward. However, if you plan on a quick dive for the gas, you can disable the stop/start feature by putting the shifter into sport mode.
Braking with Convention

This 7’s hybridity is also inconspicuous under braking. Although the mere mention of regenerative braking usually erodes the feel of the stop pedal in question, the ActiveHybrid 7’s brakes remain firm and linear. We noticed slight lurches under deceleration, but they seem to be the fault of the transmission downshifting, and not attributable to the brakes. Of course, the fact that the transmission is causing the disruptions doesn’t lessen their obnoxiousness or somehow make them more welcome in an otherwise serene car.

A mild-hybrid setup requires a smaller battery than more-advanced systems, and the 7 hides its lithium-ion pack under the trunk floor. It deals a meager one-cubic-foot blow to trunk volume—dropping it from 14 to 13—leaving BMW with a one-cube advantage over the LS600hL. BMW engineers tell us trunk space is the reason the hybrid 7-series and ActiveHybrid X6—which is launching simultaneously—use different systems. Although the X6’s full-hybrid setup allows for greater gains in fuel economy, its larger battery would have consumed more of the already-tight trunk space. Also, BMW is quick to point out that the battery in the trunk helps preserve the 7’s weight distribution, which is the same 51.5/48.5-percent front/rear for the long-wheelbase car as it is for the nonhybrid version, while the stubbier model pushes a bit more forward for 51.3/48.7. Weight increases by about 250 pounds from the hybrid components and the beefier rear axle borrowed from the V-12 7-series, necessitated by the increased torque load.

Look, Ma, Fewer Emissions!

Like other hybrids based on plain old polluters, the hybrid 7-series relies on badging to convey its uniqueness, although it’s not so subtle compared with other 7s. “ActiveHybrid 7” badges adorn the trunklid and C-pillars, and there’s also a unique 19-inch wheel design and a bespoke Bluewater Metallic color. (We’d have gone with a nice peaceful gray and called it “Blackwater Metallic.”)

Interior cues are limited to some tweaks to the instrumentation—an instant fuel-economy meter and the battery-charging monitor live in the lower part of the tach—and additional displays in the vehicle information screen. One, a bar graph, shows how active the hybrid system has been for the past 15 minutes, and the other shows the usual hybrid energy flow in beautiful high definition. Otherwise, it’s the same old 7-series, which is to say it is attractive, spacious, and comfortable (especially in long-wheelbase form).

How Much Did Captain Planet’s Costume Cost?

It is not, however, the same old pricing. Like the ActiveHybrid’s acceleration, the sticker price will get a little electronic boost when the hybrid 7 goes on sale here in the spring of 2010. Figure on $100,000 to $110,000 in the U.S., depending on how BMW decides to equip it. Considering the 750i’s base price of just over $80,000—and the more-palatable $7500 premium for the hybrid in Europe—that’s quite a leap, but if BMW rolls in one or two of the big-money options packages, that could start to look a little more acceptable.

So now there are two ways to spend $100,000 on a full-size luxury hybrid sedan. We’d buy this one. (As long as 2000 U.S. customers agree with us, BMW will be happy.) Then again, if BMW and Lexus were buying retired tugboats, lining them in leather, and putting wheels on them for street use, we’d have an opinion on which of those to buy, too. But that wouldn’t make it any less of a goofy purchase.

BY JARED GALL, PHOTOGRAPHY BY FOREST CASEY October 2009
CarAndDriver.com

BMW ActiveHybrid 7


Now reviews of the second car, the 2010 BMW ActiveHybrid 7 sedan, are starting to filter out. It's one of a growing number of luxury hybrids from BMW, Cadillac, and Mercedes-Benz that join Lexus (who created the category), with Fisker arriving next year as well.
It's a mild hybrid, meaning that its electric motor restarts the engine after it shuts off at stops and also adds torque to assist the gasoline engine. But unlike such full hybrids as the ActiveHybrid X6, it cannot travel on electric power alone.

It's a mild hybrid, meaning that its electric motor restarts the engine after it shuts off at stops and also adds torque to assist the gasoline engine. But unlike such full hybrids as the ActiveHybrid X6, it cannot travel on electric power alone.

World's "fastest hybrid sedan"

Car and Driver was among the first to test the hybrid 7-Series, saying it "seems to actually make sense" [sic] relative to some other vehicles in "Bavaria's barrage of the bizarre," including the BMW X6 and the BMW 5-Series Gran Turismo.
Similar to the title of "most powerful hybrid in the world" for its ActiveHybrid X6, BMW dubs the hybrid 7 to be "the fastest hybrid sedan in the world."


Autobahn "rocket"

It's faster than the BMW 750i, which uses a similar V-8 engine, though the hybrid 7 is both slower and less expensive than the low-volume V-12 BMW 760Li.
A "brief blast up the autobahn," Car and Driver says, "confirms that the hybrid 7 rockets to its 150-mph governor without any of the lethargy commonly associated with hybrids." And the magazine saw an indicated 20 miles per gallon in usage more like that of typical U.S. drivers.

Typical buff-book sneer

The regenerative brakes were well-integrated, according to the long-established buff book, though the test driver found that the hybrid 7 jerked if he accelerated just as the engine was shutting off at a stop. The engine shut-off can be disabled by putting the transmission into Sport mode, however.
In the end, given its typical sneers toward anything with electric drive other than a Tesla Roadster, it's probably not a shock that Car and Driver dismisses the 2010 BMW ActiveHybrid 7 as "goofy".

Another joint BMW-Benz project

The ActiveHybrid 7 uses some of the same hardware as the 2010 Mercedes-Benz S400 Hybrid, including the lithium-ion battery pack and electric motor. As they did (with other partners) on the Two-Mode Hybrid project, the German luxury carmakers cooperated on their first mild hybrids.

But unlike BMW, Mercedes-Benz fitted a smaller V-6 engine to its hybrid full-size sedan to maximize fuel efficiency, giving gas mileage of 25 miles per gallon or better in real-world usage.

More mild models?

BMW is likely to extend its homegrown mild-hybrid system into other models. Peter Tünnermann, project manager for the 2010 BMW ActiveHybrid X6, told the British magazine Autocar that the company would launch a third hybrid within 12 months.
Which model? He didn't specify precisely, but he did say, "Volume models like the 3-, 5- and 7-series are clearly more suited towards a mild hybrid set-up on the basis of their packaging and broad appeal." We expect the 5-Series to be BMW's next hybrid.

By John Voelcker, Senior Editor, November 16th, 2009
GreenCarReport.com